Aneurysmal bone cyst

Aneurysmal bone cyst is a benign, blood-filled lesion in the bone that tends to expand or grow and mostly diagnosed in children and adolescents. While it is referred to as a cyst, it is a true benign bone tumor surrounded by a thin wall of bone. Aneurysmal bone cyst is a type of osseous lesion characterized by a benign pseudocyst with fibrous connective tissue stroma and large spaces filled with blood and no endothelial lining ¹. The World Health Organization (WHO) defines aneurysmal bone cyst as a benign tumorlike lesion that is described as “an expanding osteolytic lesion consisting of blood-filled spaces of variable size separated by connective tissue septa containing trabeculae or osteoid tissue and osteoclast giant cells” ². Even though aneurysmal bone cysts are not cancerous, aneurysmal bone cysts tend to grow quickly, and treatment is recommended. If an aneurysmal bone cyst is not treated it can cause pain, fractures, disrupt growth and cause neurological symptoms.

Aneurysmal bone cysts can occur in any bones, but they are more common in the long bones, most commonly found around the knee, pelvis or spine with prevalence of only 2% in the jaws ³.

Aneurysmal bone cysts are typically eccentrically located in the metaphysis of long bones, adjacent to an unfused growth plate. Although they have been described in most bones, the most common locations are ⁴:

• Long bones: 50-60%, typically the metaphysis
  • lower limb: 40%
    • tibia and fibula: 24%, especially proximal tibia
    • femur: 13%, especially proximally
  • upper limb: 20%
• Spine and sacrum: 20-30%
  • especially posterior elements, with extension into the vertebral body in 40% of cases ⁵
• Craniofacial: jaw, basisphenoid, and paranasal sinuses
• Epiphysis, epiphyseal equivalent, or apophysis: rare but important

Almost all aneurysmal bone cysts of the spine involve the posterior elements, and a high incidence of neurologic symptoms is observed, as well as more local aggressive behavior.

The pelvis accounts for approximately 50% of lesions occurring in the flat bones ⁶. Secondary lesions tend to have a predilection for the areas of the body in which the primary lesion typically arises.

Although the aneurysmal bone cyst can appear in persons of any age, it is generally a disease of the young (albeit a rare one in the very young). About 50-80% of aneurysmal bone cysts occur before age 20 ⁷, with 70-86% occurring in patients between 10 and 20 years of age ³. The mean patient age at onset is 13-17.7 years and 13 years the median age of patients reported by many studies ⁸. Most studies have also found aneurysmal bone cysts occur slightly more frequently in females than males.

Aneurysmal bone cysts are generally considered rare, accounting for only 1-6% of all primary bony tumors ⁹. A group from Austria reported an annual incidence of 0.14 aneurysmal bone cysts per 100,000 people ¹⁰; however, the true incidence is difficult to calculate because of the existence of spontaneous regression and clinically silent cases.

A biopsy-proven incidence study from the Netherlands showed that aneurysmal bone cysts were the second most common tumor or tumorlike lesion found in children ¹¹.

Aneurysmal bone cysts may occur spontaneously, or be a secondary reaction to another bony growth elsewhere in the body. Research has revealed a high incidence of accompanying tumors specifically chondroblastoma and giant cell tumors in 23 to 32 percent of patients with an aneurysmal bone cyst.

There is no consensus in the literature regarding the best therapeutic method for treating aneurysmal bone cysts. The most commonly used treatment methods are resection, curettage, embolization and intracystic injections. The choice of treatment method varies greatly, especially in children ¹². But, despite of the method chosen, the goal is always the success of the treatment, which consists of complete reossification, with new bone formation with normal volume and mineralization characteristics ¹³ and without recurrence of the cystic lesion ¹⁴. There is a 10-15 percent recurrence rate with treatment ¹⁵.

Figure 1. Aneurysmal bone cyst calcaneus

Figure 2. Aneurysmal bone cyst jaw

Figure 3. Aneurysmal bone cyst of the clavicle

Figure 4. Aneurysmal bone cyst spine

Footnote: MRI scan of the lumbar spine sagittal T1 (a) and T2 (b) Weighted images and axial sections; (c and d) of T2 weighted images showing characteristic findings of aneurysmal bone cyst with multiple fluid-fluid levels.

Aneurysmal bone cyst causes

While the cause of aneurysmal bone cysts is currently unknown. Most investigators believe that aneurysmal bone cysts are the result of a vascular malformation within the bone; however, the ultimate cause of the malformation is a topic of controversy. Different theories about several vascular malformations exist; these include arteriovenous fistulas and venous blockage. The vascular lesions then cause increased pressure, expansion, erosion, and resorption of the surrounding bone. The malformation is also believed to cause local hemorrhage that initiates the formation of reactive osteolytic tissue. Findings from a study in which manometric pressures within the aneurysmal bone cysts were measured support the theory of altered hemodynamics.

Three commonly proposed theories are as follows:

• Aneurysmal bone cysts may be caused by a reaction secondary to another bony lesion – This theory has been proposed because of the high incidence of accompanying tumors in 23-32% of aneurysmal bone cysts; although giant cell tumors of bone are most commonly present, many other benign and malignant tumors are found, including fibrous dysplasia, osteoblastoma, chondromyxoid fibroma, nonossifying fibroma, chondroblastoma, osteosarcoma, chondrosarcoma, unicameral or solitary bone cyst, hemangioendothelioma, and metastatic carcinoma; aneurysmal bone cysts in the presence of another lesion are called secondary aneurysmal bone cysts, and treatment of these aneurysmal bone cysts is based on what is appropriate for the underlying tumor
• Aneurysmal bone cysts may arise de novo; those that arise without evidence of another lesion are classified as primary aneurysmal bone cysts
• Aneurysmal bone cysts may arise in an area of previous trauma

Recently aneurysmal bone cysts have been linked to a mutation of the ubiquitin specific peptidase 6 (USP6) gene on chromosome 17. Researchers are currently working to better understand the genetic mutation, learn when it develops, and discover how it may affect a child’s development.

A certain percentage of primary aneurysmal bone cysts may be truly neoplastic—as opposed to vascular, developmental, or reactive—phenomena. It has been shown that as many as 69% of primary aneurysmal bone cysts demonstrate a characteristic clonal t(16;17) genetic translocation ¹⁸ leading to upregulation of the TRE17/USP6 oncogene ¹⁹, whereas no secondary aneurysmal bone cysts demonstrate this cytogenetic aberration.

Most primary aneurysmal bone cysts demonstrate a t(16;17)(q22;p13) fusion of the TRE17/CDH11-USP6 oncogene. This fusion leads to increased cellular cadherin-11 activity that seems to arrest osteoblastic maturation in a more primitive state ²⁰. This process may be the neoplastic driving force behind primary aneurysmal bone cysts as opposed to secondary aneurysmal bone cysts, which seem to occur reactively as a result of another underlying disease process.

Aneurysmal bone cysts consist of blood-filled spaces of variable size that are separated by connective tissue containing trabeculae of bone or osteoid tissue and osteoclast giant cells. They are not lined by endothelium. A fine needle aspiration cytology is usually nondiagnostic, often dominated by fresh blood ²¹.

Although often primary, up to a third of aneurysmal bone cysts are secondary to an underlying lesion (e.g. fibrous dysplasia, osteosarcoma, giant cell tumor, chondromyxoid fibroma6, non-ossifying fibroma, chondroblastoma) ²², ²³.

A variant of aneurysmal bone cysts is the giant cell reparative granuloma which is usually seen in the tubular bones of the hands and feet as well as in the craniofacial skeleton. Occasionally they are also seen in appendicular long bones where they are known as solid aneurysmal bone cysts. Histologically these two entities are identical ²⁴.

Aneurysmal bone cyst symptoms

Patients with aneurysmal bone cyst may present with pain, which may be of insidious onset or abrupt due to pathological fracture, with a palpable lump or with restricted movement or a combination of these symptoms in the affected area. The symptoms are usually present for several weeks to months before the diagnosis is made, and the patient may also have a history of a rapidly enlarging mass. Neurologic symptoms associated with aneurysmal bone cysts may develop secondary to pressure or tenting of the nerve over the lesion, typically in the spine.

Pathologic fracture occurs in about 8% of aneurysmal bone cysts, but the incidence may be as high as 21% in aneurysmal bone cysts that have spinal involvement.

The symptoms of an aneurysmal bone cyst can include:

• Pain
• Swelling
• Stiffness
• Deformity in the area of the growth
• The feeling of warmth over the affected area
• Decreased range of motion, weakness or stiffness
• Reactive torticollis
• Occasionally, bruit over the affected area
• Warmth over the affected area

Aneurysmal bone cyst diagnosis

Diagnostic tests to diagnose aneurysmal bone cysts, including:

• X-rays, which produce images of bones.
• Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
• Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to examine bones and produces cross-sectional images (“slices”) of the body.
• EOS imaging, an imaging technology that creates 3-dimensional models from two flat images. Unlike a CT scan, EOS images are taken while the child is in an upright or standing position, enabling improved diagnosis due to weight-bearing positioning.
• Angiography, a radiograph-type X-ray test which reveals the inside of blood vessels and organs.
• Needle biopsy, which is a procedure where a doctor places a small needle through the skin and into the lesion to withdraw a small sample of the abnormal tissue. The tissue is analyzed to confirm any findings.

In addition to diagnosing the specific type of growth your child may have, these tests will also help determine the size and location of the tumor. All of this information is crucial in determining the best treatment options for your child.

Aneurysmal bone cyst staging

The staging of benign musculoskeletal neoplasms was described by Enneking in 1986 ²⁵, who classified benign lesions into the following three broad categories:

• Stage 1: Latent (inactive)
• Stage 2: Active
• Stage 3: Aggressive

This system has been adopted by the Musculoskeletal Tumor Society (MSTS). Part of the Enneking classification contains the Lodwick radiographic grading system (see below) ²⁶.

Lodwick radiographic grading with bone destruction

Lodwick grade 1A is characterized as follows ²⁷:

• Mandatory geographic destruction
• Characteristic regular, lobulated, or multicentric edge
• No or partial cortex penetration
• Mandatory sclerotic rim
• Expanded shell optional, 1 cm or less

Lodwick grade 1B is characterized as follows:

• Mandatory geographic destruction
• Characteristic regular, lobulated, multicentric, or ragged or poorly defined edge
• No or partial cortex penetration
• Optional sclerotic rim
• If sclerotic rim present, expanded shell must be larger than 1 cm

Lodwick grade 1C is characterized as follows:

• Mandatory geographic destruction
• Edge characteristic is regular, lobulated, multicentric, ragged or poorly defined, or moth-eaten, 1 cm or smaller
• Mandatory total penetration of the cortex
• Optional sclerotic rim
• Optional expanded shell

Lodwick grade 2 is characterized as follows:

• Moth-eaten or geographic destruction – If geographic destruction, mandatory moth-eaten edge is larger than 1 cm
• By definition, total penetration of cortex
• Optional sclerotic rim, but unlikely
• Optional expanded shell, but unlikely

Lodwick grade 3 is characterized as follows:

• Mandatory permeated destruction
• Any edge
• By definition, total penetration of cortex
• Optional sclerotic rim, but unlikely

Latent or inactive musculoskeletal neoplasms

Latent (inactive) musculoskeletal neoplasms have the following characteristics:

• Asymptomatic
• Usually incidental findings
• Rare to have a pathologic fracture or other dysfunction
• May grow slowly, but almost always reach a steady state where they no longer grow
• Remain intracompartmental
• Do not deform the compartment
• If palpable, are small, movable, and nontender
• Radiography – Well marginated, with a mature shell of cortical-like reactive bone without deformation or expansion of the encasing bone; Lodwick 1A
• Isotope scan – Little or no increased uptake
• Angiography – No significant neoangiogenesis
• CT – Homogeneous density, good margination, no cortical broaching or cross-facial extension
• Histology – Low cell-to-matrix ratio; mature, well-differentiated matrices; benign cytologic characteristics; encapsulation by mature fibrous tissue or cortical bone; little or no reactive mesenchymal proliferation, inflammatory infiltrate, or neoangiogenesis about the lesions

Active musculoskeletal neoplasms

Active musculoskeletal neoplasms have the following characteristics:

• Mildly symptomatic
• Discovered because of patient discomfort or the presence of a pathologic fracture or mechanical dysfunction
• Grow steadily, continue to enlarge during observation
• Appear responsive to contact inhibition but not at normal levels
• Can expand by deformation of the overlying cortical bone, articular cartilage, or fascial septa
• Remain encapsulated
• Only a thin layer of filmy areolar tissue separates the reactive zone between the lesions and the surrounding normal tissue.
• If palpable, are small with moderate tenderness and movable (The increase in size can be felt on serial examinations.)
• Radiography – Well-defined, yet irregular margination; a mature cancellous ring margin, rather than a cortical shell; irregular or corrugated inner aspect, resulting in a septated appearance; expansion, bulging, deformation, or the combination of overlying cortex/reactive bone is frequently observed; Lodwick 1B
• Isotope scan – Increased isotope uptake only around the limits of the defect
• Angiography – Often, a reactive angiogenesis is observed around the lesion, almost never within.
• CT – Homogeneous density; irregular but intact reactive bone, expansion of the overlying cortex, and intracompartmental containment by bone or fascia
• Histology – Relatively balanced cell-to-matrix ratio; well-defined matrices; benign cytologic characteristics; intact capsule of mature fibrous tissue and/or cancellous bone; narrow zone of mesenchymal, inflammatory, and vascular reactive tissue between the capsule and the surrounding normal tissue; resorption of the preexisting bone by osteoclasts, rather than by neoplastic cells, as the mechanism of expansion; may have areas of intermittent resorption that produce an irregular, serrated, and sometimes corrugated interface between the capsule and the adjacent reactive bone

Aggressive musculoskeletal neoplasms

Aggressive musculoskeletal neoplasms have the following characteristics:

• Despite being benign, may act more like a low-grade malignancy
• Often symptomatic
• Discovered because of patient discomfort, a growing mass, or a pathologic fracture
• If palpable, are often large and tender; may feel rapid enlargement on serial physical examinations; may feel more fixed
• May have an inflammatory appearance
• Little contact inhibition
• Penetrate or permeate the natural barriers to tumor growth, which are cortical bone, fascial septa, and articular cartilage
• Penetrate the capsule with fingerlike projections directly into the surrounding zone
• Destroy or resorb the surrounding bone or fascia and permeate into adjacent tissues or compartments rather than expanding by concomitant endosteal resorption and subperiosteal apposition
• In unrestrained areas, may expand rapidly and may be preceded by a pseudocapsule
• Radiography – Ragged, permeative interface with adjacent bone; incomplete attempts at containment by reactive bone; cortical destruction; endosteal buttresses; periosteal Codman triangles; rapid soft-tissue expansion; Lodwick 1C
• Isotope scan – Increased uptake in the early vascular phase and the late bone phase, often beyond radiographic limits
• Angiography – Distinct reactive zone of neovasculature on the early arterial phase and an intralesional hypervascular blush on the late venous phase
• CT – Nonhomogeneous, mottled, attenuating areas with defects in attempts at reactive containment; early extracompartmental extension from bone; indistinct margins in soft tissues; possible neurovascular bundle involvement
• Histology – High cell-to-matrix ratio; clearly differentiated matrices of varying maturity; predominantly benign cytologic characteristics without anaplasia or pleomorphism, but with frequent hyperchromatic nuclei; mitosis occasionally encountered; possible vascular invasion; extensions are usually still continuous with the main mass but may have some satellite lesions; thick, succulent zone of reactive tissue between the penetrated capsule and the more peripheral normal tissue (zone or pseudocapsule encircles but does not inhibit growth of the aggressive tumor; however, it does inhibit tumor nodules from extending directly into normal tissue); destruction of surrounding bone via reactive osteoclasts, not by tumor cells; tumor fingers that may grow into the reactive bone

Aneurysmal bone cyst treatment

There are many treatment options available for bone and soft tissue tumors, and some children will need a combination of these therapies. Orthopaedic, oncology and other specialists collaborate to provide your child with individualized care and the best possible outcomes. Your child’s clinical team will recommend the best treatment for your child’s individual situation.

Treatment for aneurysmal bone cysts may include:

• Intralesional curettage, which involves scraping out the bone to completely remove the tumor and all cyst lining
• Intraoperative adjuvants — such as cryotherapy (liquid nitrogen), phenol (a chemical) or cauterization (burning the tumor bed) — which are used to remove microscopic tumor cells
• Bone grafting, a surgical procedure to replace missing bone with artificial graft material or cadaver bone

Depending on the size and location of aneurysmal bone cyst removed, your child may be able to return home that day or may spend one night in the hospital.

Aneurysmal bone cysts generally are treated surgically usually with curettage and resection ²⁸. The extent of the treatment depends on the localization of the cyst, its size, its clinical characteristics and the age of the patient ²⁹. With the vascular type, bleeding may be intense ³, especially when the lesion is reached. Accordingly, preoperative embolization is commonly performed to minimize excessive bleeding during the curettage procedure.

Some anatomic locations may be difficult to access surgically. If this situation is encountered, other methods of treatment, such as intralesional injection, selective serial arterial embolization and sclerotherapy performed by an interventional radiologist, may be successful ¹². Percutaneous embolization, or sclerotherapy, has been considered a treatment option for aneurysmal bone cysts as reported by some authors ¹² primarily because, if performed by an experienced professional, it is an easy, safe, cost-effective and minimally invasive procedure compared to surgery. In addition, a success rate of over 90% with the use of sclerotherapy for treating aneurysmal bone cysts is reported ³⁰.

It is possible to find different fibrosing agents in the literature, including Ethibloc®, Absolute Alcohol and Histoacryl® ¹⁴. However, the most commonly used agents are Ethibloc and Absolute Alcohol.

Histoacryl® consists of an acrylic resine (n-butyl-2-cyanoacrylate) that acts as a tissue glue, and in contact with blood, it is quickly polymerized, preventing bleeding ³¹. In order to prevent n-butyl-2-cyanoacrylate solidification from occurring too fast, mixing with lipiodol is required ³¹. After injection, the cystic lesion is filled with this solidifying mixture that is visualized as an opacified image ³². The Histoacryl® will then be reabsorbed, and the reossification process will take place in the region of the lesion ³². Many authors had demonstrated new bone formation occurring in different areas of the human body when sclerosis of bone lesions are performed with fibrosing agents ³³.

The first use of n-butyl-2-cyanoacrylate in sclerotherapy was reported by Soehendra et al. in 1986 ³⁴, who used this tissue adhesive agent to treat bleeding gastric varices, reporting the success of the therapy in 3 patients. Since then, many authors have begun to use this fibrosing agent in sclerotherapy.

However, since aneurysmal bone cysts are most frequently found in the long bones, the therapeutic procedures most commonly reported also involve these skeletal regions. According to the literature, percutaneous embolization with Histoacryl® is generally used to treat aneurysmal bone cysts in long bones ¹⁴. In addition, this fibrosing agent is the only recommended to treat aneurysmal bone cyst in the skull and spine, due to the considerable inflammatory reaction caused by Ethibloc ¹⁴. Rossi et al. ³⁵ reported 36 aneurysmal bone cysts (4 in the thoracic cage, 6 in the spine, 9 in the long bones and 17 in the pelvis) treated with n-butyl-2-cyanoacrylate injection. The authors reported a success rate of 94%, and in most lesions (61%) only one embolization was required. In a total of 55 procedures performed, complications were observed only in 3 of them (5%) ³⁵.

The literature also reports the use of Histoacryl® in other facial lesions. Alaraj et al. ³⁶ reported a series of 20 patients with cranial, facial, and neck tumors treated with n-butyl-2-cyanoacrylate embolization, either preoperatively or palliatively in cases of uncontrollable bleeding.

In the future, advances in osteoinductive materials (eg, genetically engineered bone morphogenic protein) may offer a less invasive treatment of aneurysmal bone cyst.

Impending pathologic fracture, especially a fracture of the hip, is a challenging problem and an indication for intervention, which often includes curettage, adjuvant treatment, and internal fixation.

Rarely, asymptomatic aneurysmal bone cysts may be seen in which there is clinically insignificant destruction of bone. In such cases, close monitoring alone of the lesion may be indicated because of the evidence that some aneurysmal bone cysts spontaneously resolve. When a patient is monitored in this manner, the diagnosis must be certain, and the lesion should not be increasing in size.

Surgical therapy

Extensive preoperative planning should be completed with the use of cross-sectional imaging. Embolization as a treatment or preoperative technique should be considered. When possible, a tourniquet should be used. Thought should also be given to what possible methods and materials may be needed to provide stability after aneurysmal bone cyst excision or resection.

Depending on the size and nature of the lesion, the patient’s fluid volume and blood loss may have to be monitored closely.

Curettage and excision

The unusual stage 1 aneurysmal bone cyst can be treated with intralesional curettage ³⁷; the more common stage 2 aneurysmal bone cyst is treated by intralesional excision. The difference between curettage and excision is that excision involves wide unroofing of the lesion through a cortical window by careful abrasion of all the surfaces with a high-speed burr and, possibly, local adjuvants such as phenol, methylmethacrylate (MMA), or liquid nitrogen. These adjuvants are controversial because firm evidence that they are effective is lacking, and their use entails considerable risk.

En-bloc or wide excision is typically reserved for stage 3 aneurysmal bone cysts that are not amenable to intralesional excision (eg, extensive bony destruction); the recurrence rate after en-bloc excision is about 7%. Reconstructive options after wide excision include structural allografting and reconstruction with either endoprostheses or allograft-prosthetic composites.

In the past, intralesional excision was the mainstay of treatment. The aneurysmal bone cyst is accessed, a window is opened in the bony wall, and then the contents of the aneurysmal bone cyst are removed. Excision of the walls with curettes, rongeurs, or high-speed burrs has been described. The intralesional method leaves more bony structure intact than en-bloc or regional resection.

Intralesional excision may also be used around joints and other vital areas to try to preserve function. The defect may then be filled with bone chips, bone strut, or other supporting material to add strength and to enhance healing of the excised area.

Concerns for local resection include the following:

• The region must be expendable and not affect function (eg, spinous process, rib, clavicle, or fibula)
• Some investigators believe that elective arterial embolization should be tried first if it is not contraindicated

Concerns for en-bloc excision of a deep lesion include the following:

• Resection destabilizes the area; some surgeons use more than one third of the bone width
• Loss of function (eg, joint loss) is possible
• Some investigators believe that elective arterial embolization should be tried first if it is not contraindicated

Concerns for intralesional removal include the following:

• The area may be surgically inaccessible
• Some investigators believe that elective arterial embolization should be tried first if it is not contraindicated

Adjuvant therapy

The surgeon may also use adjuvant therapy, which extends the area of treatment beyond that which can be physically excised. The use of liquid nitrogen, phenol, argon beam gas plasma photocoagulation, and polymethylmethacrylate (PMMA) may achieve an extended area of treatment.

The adjuvants involve the use of chemical, freezing, or thermal means to cause bone necrosis and microvascular damage to the walls of the physically excised cyst, disrupting the possible etiology. Compared with en-bloc and regional resection, the use of adjuvants leaves more bone intact, and an increased area is treated compared with the area treated with intralesional resection alone.

Liquid nitrogen is the most popular adjuvant, and it is often described in the literature. After the aneurysmal bone cyst is exposed and a window is opened, liquid nitrogen may be applied by pouring it into the cyst through a funnel or by using a machine that is designed to spray the liquid onto the walls of the lesion. The surgeon should be sure to leave the window open, allowing the gas to escape.

A total of two or three cycles of freezing and thawing should be used to obtain maximum bone necrosis. The surrounding tissue, especially the neurovascular bundles, must be protected to ensure these structures are not damaged. Avoiding the use of a tourniquet with cryotherapy is suggested to keep the surrounding tissue vascularized, making it more resistant to freezing.

Phenol is much less often used as an adjuvant. Some authors have questioned the effectiveness of phenol because of its poor penetration of bony tissue compared with that of liquid nitrogen. However, phenol has had some success in certain studies, and it has the benefit of being easy to use. Phenol is simply applied to the mechanically removed walls by using soaked swabs. Any remaining phenol is removed with suction, and the cavity is filled with absolute alcohol. Finally, the cavity is irrigated with isotonic sodium chloride solution.

Polymethylmethacrylate (PMMA) may also be used, though the effectiveness of its thermal properties in causing bone necrosis has been questioned in the literature. However, polymethylmethacrylate (PMMA) does have the benefit of rendering a large lesion mechanically sound and making it easier to recognize a local recurrence. If polymethylmethacrylate (PMMA) is used in a subchondral location, the joint surface should be protected by placing cancellous grafts or Gelfoam (Pharmacia & Upjohn Co, Kalamazoo, MI) before cementation. It is not clear that removing the cement and replacing it with a bone graft is necessary.

Argon beam coagulation has also been used in several studies, with some promising results ³⁸. One study noted that surgical treatment with curettage and adjuvant argon beam coagulation is an effective treatment option for aneurysmal bone cyst; the primary complication was postoperative fracture ³⁸.

An additional study found that argon beam photocoagulation, while avoiding the toxic effects of phenol, yielded statistically equivalent recurrence rates, functional outcomes, and complication rates in the treatment of benign-aggressive bone tumors ³⁹. However, the authors also noted an increased fracture rate in the argon beam photocoagulation cohort as compared with the phenol cohort.

Concerns for adjuvant intralesional therapy include the following:

• Substances such as liquid nitrogen and phenol could penetrate tissues and damage the surrounding structures, with neural and vascular tissues being at particularly high risk; for this reason, some investigators discourage the use of intralesional therapy in the spine
• Caution should be used in areas prone to fracture; liquid nitrogen and argon beam photocoagulation can make the surrounding bone stock more brittle and thus increase the likelihood of fracture

Additional considerations

NOTE: Special consideration is necessary in dealing with aneurysmal bone cysts that are near open physes. The reader is referred to the literature for general considerations when operating around physes. The reported rate of physeal injury is significant, and patients and their families must be made aware of this possibility. Furthermore, it has been shown that attempts to spare the adjacent physes by performing a less-than-aggressive curettage of aneurysmal bone cysts have resulted in increased risk of local recurrence in patients with open growth plates ⁴⁰.

Spinal aneurysmal bone cysts usually cause neurologic symptoms and pose treatment challenges. The details of surgical excision can be found elsewhere. There is evidence to support an attempt at one or two trials of selective arterial embolization before surgical excision.

A group in Japan developed an endoscopic approach to the treatment of aneurysmal bone cyst ⁴¹. They successfully treated four patients with aneurysmal bone cysts that lacked the aneurysmal component. The technique was completed with a variety of curettes, ball forceps, Kirschner wires (K-wires), an arthroscope, and a drill. The method may leave a more stable structure and is minimally invasive.

Treatment for a secondary aneurysmal bone cyst is that which is appropriate for the underlying lesion.

Selective arterial embolization

Selective arterial embolization has shown much promise for aneurysmal bone cysts in small studies. However, the number of cases treated with this therapy is not large, both because aneurysmal bone cysts are rare and because selective arterial embolization has been available only since the 1980s ⁴².

With the use of angiography, an embolic agent is placed at a feeding artery to the aneurysmal bone cyst, cutting off the nutrient supply and altering the hemodynamics of the lesion. Various materials, such as springs and foam, have been used to create the emboli.

Selective arterial embolization has the advantage of being able to reach difficult locations, being able to save joint function when subchondral bone destruction is present, and making the complications that are associated with invasive surgery (eg, bleeding) less likely to occur. Selective arterial embolization may be performed within 48 hours before surgery to reduce the amount of intraoperative hemorrhage.

Some of the literature suggests that selective arterial embolization can be a primary treatment for aneurysmal bone cyst if the following conditions are met:

• Histologically confirmed tissue diagnosis of aneurysmal bone cyst
• Technical feasibility and safety
• Stability; no evidence of pathologic fracture or impeding fracture
• No neurologic involvement

Contraindications for selective arterial embolization include the following:

• Uncertain diagnosis; need to perform an open biopsy
• Structural instability; pathologic or impending fracture
• Neurologic symptoms
• Mechanical disruption
• Unsafe location to embolize with angiography or anatomically (eg, segmental arteries, certain cervical and thoracic areas that may lead to spinal cord ischemia, or subcutaneous bones [such as the clavicle or iliac crest] that may lead to adjacent skin necrosis and need for flap or skin graft coverage)

Intralesional injection

Only case evidence exists for intralesional injection, but the injection may be attempted for cases in which surgical access is difficult and for those in which other modalities are contraindicated ⁴³.

Note: Do not use this approach if the patient has allergies to the injection components, a pathologic or impeding fracture, neurologic symptoms, or unbearable symptoms such as pain. Do not use intralesional injection if a more proven treatment is indicated.

There has also been case evidence for the use of calcitonin ⁴⁴ and methylprednisolone injections in the regression of aneurysmal bone cysts. This is thought to combine the inhibitory angiostatic and fibroblastic effects of methylprednisolone with the osteoclastic inhibitory effect and the trabecular bone-stimulating properties of calcitonin. The injections are performed under computed tomography (CT) guidance and anesthesia. Growth of the aneurysmal bone cyst must be closely monitored, and the treatment may need to be repeated several times. Years may pass before the aneurysmal bone cyst resolves.

ETHIBLOC (Ethicon, Norderstedt, Germany) injection is also performed under CT guidance and anesthesia ⁴⁵. The injected solution is a mixture of zein, oleum papaveris, and propylene glycol and acts as a fibrosing agent, and an inflammatory reaction may occur after its administration. Bony healing may take months to years. Side effects (eg, localized thrombosis, pulmonary embolus, osseocutaneous fistula formation, and severe surrounding tissue necrosis) make it a poor first-line choice in the absence of an obvious surgical contraindication ⁴⁶.

Some case evidence also suggests healing improvement when systemic calcitonin treatment is used as an adjuvant to other treatment modalities.

An Australian study by Clayer ¹⁵ in 15 patients with pathologically confirmed aneurysmal bone cyst suggests that percutaneous aspiration and injection of aneurysmal bone cysts using an aqueous solution of calcium sulfate may have value. All patients except one who have reported pain before the procedure were completely without symptoms at 4 weeks post injection. The calcium sulfate was reabsorbed within 8 weeks.

During the minimum 2-year follow-up period, two patients developed local recurrence of the lesion, one of whom later developed a pathologic fracture. Two other patients sustained pathologic fractures at 12 and 22 months post injection, respectively. Clayer concluded that this procedure has “early clinical and radiological responses and a low complication rate in a consecutive group of patients with aneurysmal bone cyst” ¹⁵.

In several series, intralesional percutaneous injection of doxycycline has been reported to be beneficial in inducing stromal cell necrosis, reversing bone destruction, and preserving neighboring anatomy including physes and subchondral bone ⁴⁷. The principal proposed mechanisms of action for the success seen include the following ⁴⁸:

• Matrix metalloproteinase (MMP) and angiogenesis inhibition
• Osteoclast inhibition and apoptosis
• Enhanced osteoblastic bone healing

Contraindications for intralesional injection are as follows:

• Uncertain diagnosis; need to obtain an open biopsy
• Structural instability; pathologic or impending fracture
• Neurologic symptoms
• Mechanical disruption
• Allergy to injected substance
• Unbearable symptoms; lengthy time to resolution.

Treatment complications

Complications can vary with the location in which the aneurysmal bone cyst arises. Many of these are related to the proximity of the surrounding tissues.

Universal complications that have been described with surgery include the following:

• Recurrence
• Blood loss
• Wound infection
• Wound slough
• Wound hematoma
• Osteomyelitis
• Damage to the surrounding tissue
• Possible physis damage
• Pulmonary embolism

Additional complications that have been shown with spinal locations include the following:

• Tear of the dura
• Transient spastic paralysis from hematomas
• Tear in the vena cava
• Persistent back ache
• Deformity
• Neurologic symptoms

Complications that are associated with liquid nitrogen include the following:

• Rare gas embolism
• Rare late fracture
• Wound necrosis
• Damage to the surrounding tissue (eg, neurovascular bundles, physis)

A complication that is associated with phenol is necrosis of the surrounding tissue exposed to the phenol (eg, neurovascular bundles, physis).

A complication that is associated with selective arterial embolization is unintentional embolization of a vital area.

Finally, fracture risk may be elevated in those adjuvantly treated with argon beam photocoagulation, particularly in weightbearing bones.

Aneurysmal bone cyst recurrence

Aneurysmal bone cysts can recur in 10-15 percent of patients, so it is important for your child to continue to see your child’s surgeon after treatment. Recurrence usually happens within the first year after surgery, and almost all episodes occur within 2 years ⁴⁹. However, patients should still be monitored on a regular basis for 5 years. It is beneficial to detect recurrence early when the lesion is still small and easier to treat. Children should be monitored until they have reached maturity to ensure that any possible recurrence does not cause deformity or interfere with their growth. Any patients who have received radiation should be monitored for life because of the risk of secondary sarcoma.

Your child will see the orthopaedic surgeon about one to two weeks after surgery, then again every three to four months for two years to monitor for possible recurrence of the growth.

During follow-up visits, X-rays and other diagnostic testing of the tumor site are recommended to closely monitor your child’s health, check the reconstruction, and make sure there is no recurrence.

If the aneurysmal bone cyst returns, surgeons will treat the recurrence with intralesional curettage, intraoperative adjuvants, and bone grafting.

In most cases, an aneurysmal bone cyst tumor will not recur more than two years after surgery.

In a published review of 897 cases of aneurysmal bone cyst, the following rates of occurrence were reported ⁵⁰:

• Tibia – 17.5%
• Femur – 15.9%
• Vertebra – 11.2%
• Pelvis – 11.6%
• Humerus – 9.1%
• Fibula – 7.3%
• Foot – 6.3%
• Hand – 4.7%
• Ulna – 3.8%
• Radius – 3.1%
• Other – 9.2%

Spontaneous regression may occur, including following partial removal, but this is not the typical natural history ⁵¹.

Aneurysmal bone cyst prognosis

The prognosis for an aneurysmal bone cyst is generally excellent, though some patients need repeated treatments because of recurrence, which is the most common problem encountered when treating an aneurysmal bone cyst.

The overall cure rate is 90-95% ⁵². A younger age, open growth plates, and a metaphyseal location all have been associated with an increased risk of recurrence ⁵². The stage of the aneurysmal bone cyst has not been shown to influence the rate of recurrence; however, most clinicians believe that Enneking/Musculoskeletal Tumor Society (MSTS) stage 3 lesions have the highest recurrence rate, other factors being equal. Capanna morphologic types I and II recur more often than types III, IV, and V.

Reported primary recurrence rates have varied greatly. Small studies have shown a benefit to using selective arterial embolization, and some authors advocate it as a first-line treatment. Other authors argue that not enough data on selective embolization exist and that surgery is the first-line treatment. Intralesional excision has the most data to suggest that it is a safe and effective method.

Recurrence rates for different techniques have varied. Some studies have reported recurrence rates as high as 59% with intralesional excision ⁵³ and as low as 0% with resection ⁵⁰. In a summary of studies of different treatment methods, the following rates of recurrence were reported ⁵⁰:

• Irradiation – 34 performed with 4 recurrences (11.8% recurrence rate)
• Irradiation and curettage – 35 performed with 5 recurrences (14.3% recurrence rate)
• Curettage and bone graft – 484 performed with 149 recurrences (30.8% recurrence rate)
• Curettage and cryobiopsy – 78 performed with 10 recurrences (12.8% recurrence rate)
• Marginal resection – 81 performed with 6 recurrences (7.4% recurrence rate)
• Wide resection – 59 performed with 0 recurrences (0% recurrence rate).

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Kids sprained ankle

A sprained ankle means one or more ligaments on the outer side of your ankle were stretched or torn. Ankle sprains are one of the most common injuries in children. Ankles are made up of three bones with ligaments (tough, stretchy tissue that hold the bones together). The ligaments help stop the ankle joint from moving around too much.

Ankle sprains usually happen when there is a sudden movement or twist – often when the foot rolls over – and the ligaments are overstretched. This causes tears and bleeding (which show as bruising and swelling) around the ankle joint. These movements are more likely to happen when a person is running, jumping or quickly changing direction e.g. in sports such as basketball, netball or football. Risk factors for both include poor conditioning, fatigue, poor warm up, slippery surfaces and poorly fitting footwear.

Pain, swelling, bruising, tenderness, difficulty moving the ankle or difficulty walking are common symptoms of an ankle sprain. However,  symptoms of a severe sprain are similar to those of a broken bone and require prompt medical evaluation.

A sprained ankle can vary greatly in severity from a minor “rolled ankle” to a complete ligament rupture with or without bone tendon or muscle injury. They are graded as 1, 2 or 3 depending on the severity. If a sprained ankle is not treated properly, you could have long-term problems. Typically sprained ankle is rolled either inward (inversion sprain) or outward (eversion sprain). Inversion sprains cause pain along the outer side of the ankle and are the most common type. Pain along the inner side of the ankle may represent a more serious injury to the tendons or to the ligaments that support the arch and should always be evaluated by a doctor.

Ankle sprains happen when you overstretch or torn a ligament. Ankle sprains occur most commonly by a sudden twisting or rolling action of your ankle often on unstable irregular surfaces. The ligaments affected is determined by the direction the foot rolls. The most common ankle sprain is the ligament on the side which occurs when the foot is turned in.

Certain factors can put a person at greater risk of spraining their ankle including poor footwear, not warming up before exercising, tired muscles and playing sport, previous injury, reduced strength, poor biomechanics or poor balance receptors. You’re most likely to sprain your ankle when you have your toes on the ground and heel up (plantar flexion). This position puts your ankle’s ligaments under tension, making them vulnerable. A sudden force like landing on an uneven surface may turn your ankle inward (inversion). When this happens, one, two or three of your ligaments may be hurt.

A sprained ankle can be difficult to differentiate from a fracture (broken bone) without an x-ray. If you are unable to bear weight after this type of injury, or if there is significant swelling or deformity, you should seek medical treatment from a doctor. This may be your primary care physician, an emergency department, or an orthopaedist, depending on the severity of your injury.

Ankle sprains are very common injuries. There’s a good chance that while playing or stepping on an uneven surface you sprained your ankle–some 25,000 people do it every day.​​​

Sometimes, it is an awkward moment when you lose your balance, but the pain quickly fades away and you go on your way. But the sprain could be more severe; your ankle might swell and it might hurt too much to stand on it. If it’s a severe sprain, you might have felt a “pop” when the injury happened.

Treatment for a sprained ankle depends on the severity of the injury. Although self-care measures and over-the-counter pain medications may be all you need, a medical evaluation might be necessary to reveal how badly you’ve sprained your ankle and to determine the appropriate treatment.

Minor ankle strains/sprains require rest, ice, compression, elevation (RICE) and over-the-counter pain relievers for treatment. An ankle brace may be helpful to support the ankle while it heals.

Surgical treatment for ankle sprains is rare. Surgery is reserved for injuries that fail to respond to nonsurgical treatment, and for patients who experience persistent ankle instability after months of rehabilitation and nonsurgical treatment.

Ankle Joint ligaments

The ankle (talocrural) joint includes two articulations—a medial joint between the tibia and talus and a lateral joint between the fibula and talus, both enclosed in one joint capsule. The malleoli of the tibia and fibula overhang the talus on each side like a cap and prevent most side-to-side motion. The ankle therefore has a more restricted range of motion than the wrist.

Ligaments are strong, fibrous tissues that connect bones to other bones. The ligaments in the ankle help to keep the bones in proper position and stabilize the joint.

The ligaments of the ankle include (1) anterior and posterior tibiofibular ligaments, which bind the tibia to the fibula; (2) a multipart medial (deltoid) ligament, which binds the tibia to the foot on the medial side; and (3) a multipart lateral (collateral) ligament, which binds the fibula to the foot on the lateral side.

Most sprained ankles occur in the lateral ligaments on the outside of the ankle. Sprains can range from tiny tears in the fibers that make up the ligament to complete tears through the tissue.

The ankle joint is responsible for plantarflexion and dorsiflexion of the ankle. The subtalar joint lies underneath the true ankle joint and is the articulation between the talus and calcaneus. It assists the talo-crural joint in inversion and eversion. Most ankle sprains occur from an inversion mechanism of injury (rolled in).

The calcaneal (Achilles) tendon extends from the calf muscles to the calcaneus. It plantarflexes the foot and limits dorsiflexion. Plantar flexion is limited by extensor tendons on the anterior side of the ankle and by the anterior part of the joint capsule.

The most commonly injured ligaments of the ankle are the lateral ligaments which sit on the outside of the ankle. These include the anterior talofibular ligament, calcaneofibular ligament and posterior talofibular ligament. The ligament on the inside of the ankle is called the deltoid ligament which is much stronger and hence more difficult to injure.

Sprains (torn ligaments and tendons) are common at the ankle, especially when the foot is suddenly inverted or everted to excess. They are painful and usually accompanied by immediate swelling. They are best treated by immobilizing the joint and reducing swelling with an ice pack, but in extreme cases may require a cast or surgery.

High ankle sprains refer to injury to the inferior tibiofibular ligaments and syndesmosis which bind the tibia (shin bone) and fibula (calf bone) together above the ankle. A high ankle sprain is a much more debilitating injury, requiring a longer recovery time.

Figure 1. Ankle joint ligaments

What is Chronic Ankle Sprains?

Once you have sprained your ankle, you may continue to sprain it if the ligaments do not have time to completely heal. It can be hard for patients to tell if a sprain has healed because even an ankle with a chronic tear can be highly functional because overlying tendons help with stability and motion.

If pain continues for more than 4 to 6 weeks, you may have a chronic ankle sprain. Activities that tend to make an already sprained ankle worse include stepping on uneven surfaces and participating in sports that require cutting actions or rolling and twisting of the foot.

Abnormal proprioception—a common complication of ankle sprains—can also lead to repeat sprains. There may be imbalance and muscle weakness that causes a reinjury. If you sprain your ankle over and over again, a chronic situation may persist with instability, a sense of the ankle giving way, and chronic pain. This can also happen if you return to work, sports, or other activities before your ankle heals and is rehabilitated.

How long does a sprained ankle take to heal?

After 2 weeks, most ankle sprains and strains will feel better. Avoid strenuous exercise such as running for up to 8 weeks, as there’s a risk of further damage.

Severe ankle sprains (grade 2 and 3) and strains can take months to get back to normal.

Most importantly, successful outcomes are dependent upon patient commitment to rehabilitation exercises. Incomplete rehabilitation is the most common cause of chronic ankle instability after a sprain. If a patient stops doing the strengthening exercises, the injured ligament(s) will weaken and put the patient at risk for continued ankle sprains.

I sprained my ankle last spring while I was running. The ankle doesn’t really hurt anymore, but it keeps ‘giving out’. What should I do?

Ankle sprains are the most common foot and ankle injury in sports. Typically, sprains occur when the foot inverts with an awkward step while running or jumping. As the foot rotates inward, the ligaments on the outside, or lateral aspect of the ankle, are stretched, causing swelling and pain. Most frequently, sprains will recover completely with rest, ice, compression, elevation and early mobilization.

In less than 10% of cases, while ankle swelling and pain improves, the ankle continues to “give out” or feel unstable. Classically, this occurs when walking on uneven ground or when stepping off of a curb. Repeated episodes of “giving out” is a condition called chronic ankle instability. Most frequently, this is a result of incomplete recovery from an acute ankle sprain that leaves the ankle with weakness and impaired postural control.

The initial treatment for chronic ankle instability is a program of structured rehabilitation with the help of a physical therapist. Exercises are aimed specifically at strengthening the peroneal tendons which run on the outside aspect of the ankle. The regimen should also include use of a balance board or similar device to work on proprioception – awareness of the position of the foot and ankle in space. Improved proprioception helps the ankle react more quickly to stresses, preventing future sprains.

After 6-8 weeks of intensive therapy, if the ankle continues to feel unstable, one might be a candidate for surgery to reconstruct the injured ankle ligaments. At this point, an MRI is helpful to identify any underlying injury such as cartilage damage at the ankle or peroneal tendon tears. Complete recovery from surgery takes at least 3 months, but patients will typically be able to return to full activity without limitation, and, most importantly, without the sensation of their ankle “giving out”.

Grades of Ankle Sprains

After the examination, your doctor will determine the grade of your sprain to help develop a treatment plan. Sprains are graded based on how much damage has occurred to the ligaments.

Some sprained ankles are minor injuries that heal with little treatment. Others can be more serious, though. The three grades of ankle sprains, based on how much damage is done to the ligaments, are (see Figure 2 below):

Figure 2. Sprained ankle grades

Grade 1 Sprain (Mild)

• This is a mild sprain where ligaments stretch slightly.
• Slight stretching and microscopic tearing of the ligament fibers
• Someone with a grade 1 sprain will feel some soreness and may notice a bit of swelling around the ankle

Grade 2 Sprain (Moderate)

• This is a moderate sprain where ligaments tear partly, making the ankle joint feel loose.
• Partial tearing of the ligament
• Moderate tenderness and swelling around the ankle
• If the doctor moves the ankle in certain ways, there is an abnormal looseness of the ankle joint
• The ankle will feel painful, and may stay swollen for a while. Putting weight on the foot can be difficult.

Grade 3 Sprain (Severe)

• This is the most severe kind of sprain, where an ankle ligament tears completely.
• Complete tear of the ligament
• Significant tenderness and swelling around the ankle
• If the doctor pulls or pushes on the ankle joint in certain movements, substantial instability occurs
• The ankle joint will be very painful, with quite a bit of swelling. The person’s ankle will feel loose and unsteady and early on the person probably won’t be able to put any weight on the ankle.
• If there is a complete tear of the ligaments, the ankle may become unstable after the initial injury phase passes. Over time, this instability can result in damage to the bones and cartilage of the ankle joint.

Tell your doctor what you were doing when you sprained your ankle. He or she will examine it and may want an x-ray to make sure no bones are broken. Most ankle sprains do not require surgery, and minor sprains are best treated with a functional rehabilitation program.

If you repeatedly sprain the same ankle or feel pain for more than 4 to 6 weeks, you may have what’s called a chronic sprain. This type of lasting sprain can flare up and be made worse by activities that involve rolling or twisting the feet, like running, dancing, or playing sports.

Sprained ankle causes

A sprain occurs when your ankle is forced to move out of its normal position, which can cause one or more of the ankle’s ligaments to stretch, partially tear or tear completely.

The most common type of sprained ankle is called an inversion sprain, or lateral ligament sprain. With this type of sprain, the ankle turns so the sole of the foot is facing inwards, stretching and possibly damaging the ligaments on the outer part of the ankle.

You don’t have to be playing hard to injure an ankle: sprains can happen just from taking an awkward step or tripping on the stairs.

Causes of a sprained ankle might include:

• A fall that causes your ankle to twist
• Landing awkwardly on your foot after jumping or pivoting
• Walking or exercising on an uneven surface
• Another person stepping or landing on your foot during a sports activity, while you are running, causing your foot to twist or roll to the side
• Participating in sports that require cutting actions or rolling and twisting of the foot—such as trail running, basketball, tennis, football, and soccer.

Risk factors for sprained ankle

Factors that increase your risk of a sprained ankle include:

• Sports participation. Ankle sprains are a common sports injury, particularly in sports that require jumping, cutting action, or rolling or twisting of the foot such as basketball, tennis, football, soccer and trail running.
• Uneven surfaces. Walking or running on uneven surfaces or poor field conditions may increase the risk of an ankle sprain.
• Prior ankle injury. Once you’ve sprained your ankle or had another type of ankle injury, you’re more likely to sprain it again.
• Poor physical condition. Poor strength or flexibility in the ankles may increase the risk of a sprain when participating in sports.
• Improper shoes. Shoes that don’t fit properly or aren’t appropriate for an activity, as well as high-heeled shoes in general, make ankles more vulnerable to injury.

Sprained ankle prevention

The following tips can help you prevent a sprained ankle or a recurring sprain:

• Warm up before you exercise or play sports.
• Be careful when walking, running or working on an uneven surface.
• Use an ankle support brace or tape on a weak or previously injured ankle.
• Wear shoes that fit well and are made for your activity.
• Minimize wearing high-heeled shoes.
• Don’t play sports or participate in activities for which you are not conditioned.
• Maintain good muscle strength and flexibility.
• Slow down or stop activities when you feel pain or fatigue.
• Practice stability training, including balance exercises.

Signs and symptoms of ankle sprains

Signs and symptoms of a sprained ankle vary depending on the severity of the injury. If your child has sprained their ankle, they may have:

• Swelling, which develops in minutes or over several hours – this is caused by soft tissue damage
• Pain around the outside part of the ankle joint
• Bruising, which shows up within two to three days
• Ankle pain, especially when you bear weight on the affected foot
• Tenderness when you touch the ankle (injured ligaments will be quite tender to touch in that initial phase)
• Restricted range of motion
• Instability in the ankle
• If there is severe tearing of the ligaments, your child might also hear or feel a “pop” when the sprain occurs.
• In the cases of a severe ankle sprain, your child may have difficulty walking and may require the use of crutches to mobilize.

Symptoms of a severe sprain are similar to those of a broken bone and require prompt medical evaluation.

Sprained ankle complications

Failing to treat a sprained ankle properly, engaging in activities too soon after spraining your ankle or spraining your ankle repeatedly might lead to the following complications:

• Chronic ankle pain
• Chronic ankle joint instability
• Arthritis in the ankle joint

Kids sprained ankle diagnosis

During a physical, your doctor will examine your ankle, foot and lower leg. The doctor will touch the skin around the injury to check for points of tenderness and move your foot to check the range of motion and to understand what positions cause discomfort or pain.

Depending on how many ligaments are injured, your sprain will be classified as Grade 1, 2 or 3. In a mild sprain (grade 1), the ankle ligament simply is overstretched. More severe ankle sprains can involve partial tearing of the ankle ligament (grade 2), or complete tearing (grade 3).

If the injury is severe, your doctor may recommend one or more of the following imaging scans to rule out a broken bone or to evaluate in more detail the extent of ligament damage:

• X-ray. During an X-ray, a small amount of radiation passes through your body to produce images of the bones of the ankle. This test is good for ruling out bone fractures.
• Stress x-rays. In addition to plain X-rays, your doctor may also order stress X-rays. These scans are taken while the ankle is being pushed in different directions. Stress X-rays help to show whether the ankle is moving abnormally because of injured ligaments.
• Magnetic resonance imaging (MRI). MRIs use radio waves and a strong magnetic field to produce detailed cross-sectional or 3-D images of soft internal structures of the ankle, including ligaments. Your doctor may order an MRI if he or she suspects a very severe injury to the ligaments, damage to the cartilage or bone of the joint surface, a small bone chip, or another problem. The MRI may not be ordered until after the period of swelling and bruising resolves.
• CT scan. CT scans can reveal more detail about the bones of the joint. CT scans take X-rays from many different angles and combine them to make cross-sectional or 3-D images.
• Ultrasound. An ultrasound uses radio waves to produce real-time images. These images may help your doctor judge the condition of a ligament or tendon when the foot is in different positions.

How to treat a sprained ankle yourself

See your doctor if your child has pain and swelling in his ankle and you suspect a sprain. Self-care measures may be all you need, but talk to your doctor to discuss whether your child should have his ankle evaluated. If signs and symptoms are severe, your child may have significant damage to a ligament or a broken bone in his ankle or lower leg.

Care at home

If your child has sprained their ankle, you can care for them at home using first aid principles (the Rest, Ice, Compression, Elevation (RICE) strategy) and ankle exercises. For a Grade 1 sprained ankle, follow the R.I.C.E. guidelines to help bring down swelling and support the injury. Treatment should start immediately and continue for the next two to three days.

• Rest: rest the ankle by not walking on it and avoid activities that cause a lot of pain. If your child is having difficulty walking, crutches should be used. You can hire crutches from your local pharmacy.
• Ice: apply ice to the injured area for 10–15 minutes. Never place the ice directly on the skin because it can burn the skin – wrap the ice or ice pack in a tea towel or a pillow case. Ice the injury every two to four hours for two to three days, when your child is awake. You can make an ice pack using a plastic bag with some ice and water in it. This moulds better to the ankle joint area than ice alone. Don’t ice more than 20 minutes every 2 to 3 hours at a time to avoid frost bite.
• Compression: wrap a firm bandage that is not too tight and does not stop circulation or cause extra pain. The bandage should cover from just above the ankle right down to the foot. Do not cover the toes.
• Elevation: raise the ankle whenever possible to help reduce the swelling. For example, raise your child’s injured leg and rest it on some pillows while they are watching TV, reading or resting.

Some children will need medicine to help with the pain. In most cases, acetaminophen (paracetamol) is enough. Anti-inflammatory medications may help, but these are not suitable for every child. Ask your doctor for further advice. Always read and follow the instructions on the package for the appropriate dose of medication for your child. See our fact sheet Pain relief for children.

Figure 3. How to wrap a sprained ankle

In the first two to three days after your child’s injury, avoid:

• heat (e.g. heat packs or hot baths) – this increases blood flow and makes the swelling worse
• re-injury – protect the ankle joint from re-injury by keeping weight off it and moving carefully
• massage – this promotes blood flow and makes the swelling worse.

Swelling usually goes down with a few days.

• Take nonsteroidal anti-inflammatory drugs (NSAIDs). Ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs) can help relieve pain and reduce swelling in the ankle.
• Crutches. In most cases, swelling and pain will last from 2 to 3 days. Walking may be difficult during this time and your doctor may recommend that you use crutches as needed.
• Avoid activities that put pressure on your ankle. Don’t play sports that require running, cutting, or stopping quickly until your doc says it’s OK. Don’t hike, jog, or exercise on uneven surfaces until the ankle is properly healed.
• Do stretching and strengthening exercises. After the pain and swelling have improved, ask your doctor about an exercise program to improve your ankle’s strength and flexibility. Depending on the severity of the sprain, the doctor may recommend physical therapy to help the healing process.
• Immobilization. During the early phase of healing, it is important to support your ankle and protect it from sudden movements. For a Grade 2 sprain, a removable plastic device such as a cast-boot or air stirrup-type brace can provide support. Grade 3 sprains may require a short leg cast or cast-brace for 2 to 3 weeks.

For a Grade 2 sprained ankle, follow the R.I.C.E. guidelines and allow more time for healing. A doctor may immobilize or splint your sprained ankle.

A Grade 3 sprained ankle puts you at risk for permanent ankle instability. Rarely, surgery may be needed to repair the damage, especially in competitive athletes. For severe ankle sprains, your doctor may also consider treating you with a short leg cast for two to three weeks or a walking boot. People who sprain their ankle repeatedly may also need surgical repair to tighten their ligaments.

Doctors usually try immobilization and other treatments before recommending surgery. But if your doctor decides surgery is the best option, he or she may start with arthroscopy. This involves inserting a small camera device into the joint through a tiny cut. It allows the doctor to look inside the joint to see what’s going on — like if part of the ligament is caught in the joint or there are bone fragments in the joint — and treat it if necessary.

In very rare cases, doctors will recommend surgery to reconstruct a torn ligament. It’s unlikely that most teens will need this type of surgery for a sprained ankle, though. Your body will probably heal on its own as long as you don’t overdo it too quickly.

Not overdoing things is key when it comes to sprained ankle. So follow your doctor’s advice and don’t push yourself or feel pressure to get back into sports or other activities too soon. Sprains usually heal well, but they need time to get fully better.

Rehabilitating your sprained ankle

Every ligament injury needs rehabilitation. Otherwise, your sprained ankle might not heal completely and you might re-injure it. All ankle sprains, from mild to severe, require three phases of recovery:

• Phase 1 includes resting, protecting and reducing swelling of your injured ankle.
• Phase 2 includes restoring your ankle’s flexibility, range of motion and strength.
• Phase 3 includes maintenance exercises and the gradual return to activities that do not require turning or twisting the ankle. This will be followed later by being able to do activities that require sharp, sudden turns (cutting activities)—such as tennis, basketball, or football.

This three-phase treatment program may take just 2 weeks to complete for minor sprains, or up to 6 to 12 weeks for more severe injuries.

Once you can stand on your ankle again, your doctor will prescribe exercise routines to strengthen your muscles and ligaments and increase your flexibility, balance and coordination. Later, you may walk, jog and run figure eights with your ankle taped or in a supportive ankle brace.

It’s important to complete the rehabilitation program because it makes it less likely that you’ll hurt the same ankle again. If you don’t complete rehabilitation, you could suffer chronic pain, instability and arthritis in your ankle. If your ankle still hurts, it could mean that the sprained ligament has not healed right, or that some other injury also happened.

To prevent future sprained ankles, pay attention to your body’s warning signs to slow down when you feel pain or fatigue, and stay in shape with good muscle balance, flexibility and strength in your soft tissues.

Sprained ankle exercises

Rehabilitation exercises are used to prevent stiffness, increase ankle strength, and prevent chronic ankle problems.

• Early motion. To prevent stiffness, your doctor or physical therapist will provide you with exercises that involve range-of-motion or controlled movements of your ankle without resistance.
• Strengthening exercises. Once you can bear weight without increased pain or swelling, exercises to strengthen the muscles and tendons in the front and back of your leg and foot will be added to your treatment plan. Water exercises may be used if land-based strengthening exercises, such as toe-raising, are too painful. Exercises with resistance are added as tolerated.
• Proprioception (balance) training. Poor balance often leads to repeat sprains and ankle instability. A good example of a balance exercise is standing on the affected foot with the opposite foot raised and eyes closed. Balance boards are often used in this stage of rehabilitation.
• Endurance and agility exercises. Once you are pain-free, other exercises may be added, such as agility drills. Running in progressively smaller figures-of-8 is excellent for agility and calf and ankle strength. The goal is to increase strength and range of motion as balance improves over time.

How to Stretch Your Ankle After A Sprain

You should perform the following stretches in stages once the initial pain and swelling have receded, usually within five to seven days. First is restoration of ankle range of motion, which should begin when you can tolerate weight bearing.

Once ankle range of motion has been almost or completely restored, you must strengthen your ankle. Along with strengthening, you should work toward a feeling of stability and comfort in your ankle, which orthopaedic foot and ankle specialists call proprioception.

Consider these home exercises when recuperating from an ankle sprain. Perform them twice per day.

• While seated, bring your ankle and foot all the way up as much as you can.
  • Do this slowly, while feeling a stretch in your calf.
  • Hold this for a count of 10.
  • Repeat 10 times.
• From the seated starting position, bring your ankle down and in.
  • Hold this inverted position for a count of 10.
  • Repeat 10 times.
• Again from the starting position, bring your ankle up and out.
  • Hold this everted position for a count of 10.
  • Repeat 10 times.
• From the starting position, point your toes down and hold this position for a count of 10.
  • Repeat 10 times.

This stretch should be done only when the pain in your ankle has significantly subsided.

• While standing on the edge of a stair, drop your ankles down and hold this stretched position for a count of 10.
  • Repeat 10 times.
• Stand 12 inches from a wall with your toes pointing toward the wall.
  • Squat down and hold this position for a count of 10.
  • Repeat 10 times.

How to Strengthen Your Ankle After a Sprain

Following an ankle sprain, strengthening exercises should be performed once you can bear weight comfortably and your range of motion is near full. There are several types of strengthening exercises. The easiest to begin with are isometric exercises that you do by pushing against a fixed object with your ankle.

Once this has been mastered, you can progress to isotonic exercises, which involve using your ankle’s range of motion against some form of resistance. The photos below show isotonic exercises performed with a resistance band, which you can get from your local therapist or a sporting goods store.

Figure 4. Sprained ankle exercises

Range of Motion

• Ankle Alphabet: Spell out each letter of the alphabet with your foot, keeping your leg still while moving at the ankle. Use the biggest movements your ankle allows to go through the whole thing, A-Z.
• Calf Stretches: As soon as you can, start stretching your calves by putting the injured leg behind you, keeping your leg straight, and leaning pushing on a wall. If you can’t tolerate standing on your injured foot, straighten your leg by propping it up on a chair, or while sitting on your bed, then use a towel to pull the ball of your foot towards you. Hold for 30 seconds and repeat 3 times.

Strengthening

• Resisted 4-Way Ankle Holds: As pain allows, use a resistance band or towel to work against while you pull your ankle as far as you can in all 4 directions: up, down, inverted (top of foot towards the outside) and everted (sole of the foot towards the outside). Hold for 10 seconds, 5 times in each direction.
• Heel Raises: Once you can bear weight on your foot, stand on the ground and slowly raise your heels off as far as you can, hold for 5 seconds then slowly lower back down. Do 3 sets of 10 reps. You can progress this by standing half-way on a stair with both heels hanging off. Allow your heels to drop below the stair as you come down, holding that position for 5 seconds before rising back up (this can be a great way to stretch your calves too). Once you’re feeling really strong, switch to just using one foot at a time, rinse and repeat.

Balance

• Single Leg Stands: Stand on one foot (once you can tolerate it) while working up to balancing for 30 seconds. If needed, stand next to a chair or wall for support. Make it even tougher by closing your eyes, then progress to standing on a pillow to destabilize you. Stand with your affected leg on a pillow. Hold this position for a count of 10. Repeat 10 times.
• Advanced Balance Training: Once you’ve mastered single leg stands, you can really get your balance on by standing on one leg (yes, again) and putting both arms straight up above your head. Now slowly bend forward at the waist (keeping your back straight) as far as you can while keeping your balance. Not so easy, right? Try bending backwards as far as you can (hands still above your head), then to the left and to the right. Finally you can slowly twist to the left and right all while keeping balanced and tight in your core.

These same exercises that you’ve used to rehab your ankle can serve to strengthen it for future protection against another sprain. Progressing to longer periods of balancing and more reps on your resisted exercises will keep you strong and in tune with your ankle for years to come.

Once you have regained the motion and strength in your ankle, you are ready for sporting activities such as gentle jogging and biking. After you feel your ankle strength is approximately 80% of your other side, then you can begin cutting or twisting sports.

Using a brace or getting your ankle wrapped during risky activities will also help prevent future ankle sprains by adding increased support to your injured ligaments, even once they’ve healed. Whether the brace is soft or hard, find something comfortable and supportive that you’re willing to use each time you lace up your sport shoes.

Surgery

In rare cases, surgery is performed when the injury doesn’t heal or the ankle remains unstable after a long period of physical therapy and rehabilitative exercise.

Surgery may be performed to:

• Repair a ligament that won’t heal
• Reconstruct a ligament with tissue from a nearby ligament or tendon

Surgical options may include:

• Arthroscopy. During arthroscopy, your doctor uses a small camera, called an arthroscope, to look inside your ankle joint. Miniature instruments are used to remove any loose fragments of bone or cartilage, or parts of the ligament that may be caught in the joint.
  Reconstruction. Your doctor may be able to repair the torn ligament with stitches or sutures. In some cases, he or she will reconstruct the damaged ligament by replacing it with a tissue graft obtained from other ligaments and/or tendons found in the foot and around the ankle.

• Immobilization. There is typically a period of immobilization following surgery for an ankle sprain. Your doctor may apply a cast or protective boot to protect the repaired or reconstructed ligament. Be sure to follow your doctor’s instructions about how long to wear the protective device; if you remove it too soon, a simple misstep can re-tear the fixed ligament.

Rehabilitation

Rehabilitation after surgery involves time and attention to restore strength and range of motion so you can return to pre-injury function. The length of time you can expect to spend recovering depends upon the extent of injury and the amount of surgery that was done. Rehabilitation may take from weeks to months.

What is whiplash

Whiplash also known as neck sprain, is an injury to the muscles, tendons and other soft tissues of the neck ¹, ², ³, ⁴, ⁵. Whiplash injury is caused by a sudden and vigorous movement of the head, sideways, backwards or forwards. Any impact that causes your head to suddenly accelerate or decelerate can cause symptoms of whiplash. However, sometimes whiplash result in no injury or pain at all ⁶.

The term “whiplash” injury was first coined by Harold Crowe in 1928 to define acceleration-deceleration injuries occurring to the cervical spine or neck region ⁷. Later modified to an all-encompassing term known as whiplash-associated disorders (WAD), these clinical entities have been refined to describe any collection of neck-related symptoms following a car accident ⁸, ⁹. Whiplash-associated disorder is a globally important clinical, social, and financial problem ¹⁰.

Your neck is made up by the cervical spine, the first seven vertebrae of the back (see Figure 1 below). Areas of the vertebrae commonly affected are the intervertebral joints (the joints between each vertebrae), the intervertebral discs (the soft material that cushions one vertebrae from another), and the ligaments, muscles and nerve roots that hold the vertebrae together.

Rear collision motor vehicle crashes are the most common cause of whiplash injuries. Whiplash injuries can also occur in other situations where the body is exposed to sudden starts and stops such as contact sports like football, rugby or soccer. Neck sprain or neck strain are other terms that are used to describe whiplash injuries.

Approximately 120,000 whiplash injuries occur in the US each year. The statistics vary for different countries. It is very interesting to find that Australia was the most prolific countries on whiplash injury, and the United States ranked second. A study of drivers in collisions involving two cars found similar results in French (1997–2003) and Spanish databases (2002–2004): 12.2% were diagnosed with whiplash in France and 12.0% in Spain ¹¹. The annual economic cost of whiplash injury is estimated to be $3.9 billion in the United States ¹².

Generally, whiplash injury causes acute neck pain and stiffness within hours of the accident, however these symptoms may in some cases be delayed for several days.

Pain should resolve with treatment after several weeks, and most patients are fully recovered within three months of the injury. Some individuals may continue to suffer pain and headaches after this.

Whiplash symptoms often greatly improve or disappear within a few days to weeks. It may take longer for symptoms to completely disappear and some people experience some pain and neck stiffness for months after a whiplash injury.

More than 50% of whiplash resolve after a few weeks of treatment ¹³, ¹⁴, ¹⁵. However, approximately 30% of cases develop long-term complex pain related disability and persist for months or years ¹⁶, ¹⁵. Recovery following whiplash injury, if it is to occur, will occur for the most part within the first 3 months post injury ¹⁷. Current estimates suggest that approximately 50% of individuals will recover by 3 months post injury, whilst the remainder will experience mild to moderate long-term disability ¹⁸, ¹⁹, ²⁰. The development of chronic symptoms after whiplash injuries may also be influenced by psychological and social factors as well as with changes in the central nervous system (brain and spinal cord) ²⁰, ²¹, ²². In countries such as Lithuania and Greece, where there is no compensation culture and no formal compensation system for late whiplash-related injuries, the development of chronic symptoms following whiplash is a rare phenomenon ²³, ²⁴. This evidence suggests that the culture and expectations around whiplash, local insurance systems, and the prospect of monetary benefits are likely to play important roles in the prevalence of whiplash injuries and related claims, as well as in the recovery process ²⁵.

Common symptoms of whiplash include ²⁶:

• neck pain and tenderness
• neck stiffness and difficulty moving your head
• headaches
• muscle spasms
• pain in the shoulders and arms

Less common symptoms include pins and needles in your arms and hands, dizziness, tiredness, memory loss, poor concentration and irritability.

It can take several hours for the symptoms to develop after you injure your neck. The symptoms are often worse the day after the injury, and may continue to get worse for several days.

Whiplash injuries are commonly caused by:

• motor vehicle accidents (80% of whiplash injury cases) ²⁷, ²⁸
• a sudden blow to the head from contact sports such as rugby or boxing
• being hit on the head by a heavy object
• a slip or fall where the head is jolted or jarred.

Whiplash occurs when the neck is moved beyond its usual range of movement, which overstretches or sprains the soft tissues of the neck (tendons, muscles and ligaments). This causes pain and discomfort in the neck and shoulders and may also cause back pain.

The joints and ligaments of the neck are covered by muscles. So whiplash injury cannot be seen from the surface. This can be frustrating when your neck is painful. Imagine a sprained ankle. Immediately following a sprain, the ankle becomes bruised, swollen and painful to move.

Key points about whiplash:

• Whiplash injury is poorly understood, but usually involves the muscles, discs, nerves, and tendons in your neck.
• It is caused by the neck bending forcibly forward and then backward, or vice versa.
• Many whiplash injuries occur if you are involved in a rear-end automobile collision.
• Your healthcare provider will determine specific treatment for your whiplash.

Cervical spine anatomy

Your spine is made up of 24 bones, called vertebrae, that are stacked on top of one another. These bones connect to create a canal that protects the spinal cord.

Other parts of your spine include:

• Spinal cord and nerves. These “electrical cables” travel through the spinal canal carrying messages between your brain and muscles. Nerve roots branch out from the spinal cord through openings in the vertebrae (foramen).
• Intervertrebral disks. In between your vertebrae are flexible intervertebral disks. They act as shock absorbers when you walk or run.

Intervertebral disks are flat and round and about a half inch thick. They are made up of two components:

• Annulus fibrosus. This is the tough, flexible outer ring of the disk.
• Nucleus pulposus. This is the soft, jelly-like center of the disk.

The cervical spine is made up of the first 7 vertebrae and functions to provide mobility and stability to the head, while connecting it to the relative immobile thoracic spine (see the image below). The first 2 vertebral bodies are quite different from the rest of the cervical spine. The atlas, or C1, articulates superiorly with the occiput and inferiorly with the axis, or C2.

The atlas is ring-shaped and does not have a body, unlike the rest of the vertebrae. The body has become part of C2, and it is called the odontoid process, or dens. The atlas is made up of an anterior arch, a posterior arch, 2 lateral masses, and 2 transverse processes. The transverse foramen, through which the vertebral artery passes, is enclosed by the transverse process. On each lateral mass is a superior and inferior facet (zygapophyseal) joint. The superior articular facets are kidney-shaped, concave, and face upward and inward. These superior facets articulate with the occipital condyles, which face downward and outward. The relatively flat inferior articular facets face downward and inward to articulate with the superior facets of the axis.

The axis has a large vertebral body, which contains the fused remnant of the C1 body, the dens. The dens articulates with the anterior arch of the atlas via its anterior articular facet and is held in place by the transverse ligament. The axis is composed of a vertebral body, heavy pedicles, laminae, and transverse processes, which serve as attachment points for muscles. The axis articulates with the atlas by its superior articular facets, which are convex and face upward and outward.

The remaining cervical vertebrae, C3-C7, are similar to each other, but they are very different from C1 and C2. They each have a vertebral body, which is concave on its superior surface and convex on its inferior surface. On the superior surfaces of the bodies are raised processes or hooks called uncinate processes, which articulate with depressed areas on the inferior aspect of the superior vertebral bodies called the echancrure or anvil. These uncovertebral joints are most noticeable near the pedicles and are usually referred to as the joints of Luschka ²⁹. These joints are believed to be the result of degenerative changes in the annulus, which leads to fissuring in the annulus and the creation of the joint. The spinous processes of C3-C5 are usually bifid, in comparison to the spinous processes of C6 and C7, which are usually tapered.

The facet joints in the cervical spine are diarthrodial synovial joints with fibrous capsules. The joint capsules in the lower cervical spine are more lax compared with other areas of the spine to allow for gliding movements of the facets. The joints are inclined at 45° from the horizontal plane and angled 85° from the sagittal plane. This alignment helps to prevent excessive anterior translation and is important in weight bearing ³⁰.

The fibrous capsules are innervated by mechanoreceptors (types I, II, and III), and free nerve endings have been found in the subsynovial loose areolar and dense capsular tissues ³¹. In fact, there are more mechanoreceptors in the cervical spine than in the lumbar spine ³². This neural input from the facets may be important for proprioception and pain sensation and may modulate protective muscular reflexes that are important in preventing joint instability and degeneration.

The facet joints in the cervical spine are innervated by both the anterior and dorsal rami. The occipitoatlantal joint and atlantoaxial joint are innervated by the ventral rami of the first and second cervical spinal nerves. Two branches of the dorsal ramus of the third cervical spinal nerve innervate the C2-C3 facet joint, a communicating branch and a medial branch known as the third occipital nerve.

The remaining cervical facets, C3-C4 to C7-T1, are supplied by the dorsal rami medial branches that arise one level cephalad and caudad to the joint ³³. Therefore, each joint from C3-C4 to C7-T1 is innervated by the medial branches above and below. These medial branches send off articular branches to the facet joints as they wrap around the waists of the articular pillars.

Intervertebral discs are located between each vertebral body caudad to the axis. The discs are composed of 4 parts, including the nucleus pulposus in the middle, the annulus fibrosis surrounding the nucleus, and 2 end plates that are attached to the adjacent vertebral bodies. The discs are involved in cervical spine motion, stability, and weight bearing. The annular fibers are composed of collagenous sheets called lamellae, which are oriented 65-70° from the vertical and alternate in direction with each successive sheet. Therefore, the annular fibers are prone to injury with rotation forces because only one half of the lamellae are oriented to withstand the force in this direction ³². The middle and outer one third of the annulus is innervated by nociceptors, and phospholipase A2 has been found in the disc and may be an inflammatory mediator ³⁴.

Several ligaments of the cervical spine, which provide stability and proprioceptive feedback, are worth mentioning ³⁵. The transverse ligament, the major portion of the cruciate ligament, arises from tubercles on the atlas and stretches across its anterior ring while holding the dens against the anterior arch. A synovial cavity is located between the dens and the transverse process. This ligament allows for rotation of the atlas on the dens and is responsible for stabilizing the cervical spine during flexion, extension, and lateral bending. The transverse ligament is the most important ligament in preventing abnormal anterior translation ³⁶.

The alar ligaments run from the lateral aspects of the dens to the ipsilateral medial occipital condyles and to the ipsilateral atlas. The alar ligaments limit axial rotation and side bending. If the alar ligaments are damaged, as in a whiplash injury, the joint complex becomes hypermobile, which can lead to kinking of the vertebral arteries and stimulation of the nociceptors and mechanoreceptors. This may be associated with the typical complaints of patients with whiplash injuries such as headache, neck pain, and dizziness. The alar ligaments prevent excessive lateral and rotational motions, while allowing flexion and extension.

The anterior longitudinal ligament and the posterior longitudinal ligament are the major stabilizers of the intervertebral joints. Both ligaments are found throughout the entire length of the spine; however, the anterior longitudinal ligament is closely adhered to the discs in comparison to the posterior longitudinal ligament, and it is not well developed in the cervical spine. The anterior longitudinal ligament becomes the anterior atlantooccipital membrane at the level of the atlas, whereas the posterior longitudinal ligament merges with the tectorial membrane. Both ligaments continue onto the occiput. The posterior longitudinal ligament prevents excessive flexion and distraction ³⁷.

The supraspinous ligament, interspinous ligament, and ligamentum flavum maintain stability between the vertebral arches. The supraspinous ligament runs along the tips of the spinous processes, the interspinous ligament runs between the spinous processes, and the ligamentum flavum runs from the anterior surface of the cephalad vertebra to the posterior surface of the caudad vertebra. The interspinous ligament and especially the ligamentum flavum control for excessive flexion and anterior translation ³⁷. The ligamentum flavum also connects to and reinforces the facet joint capsules on the ventral aspect. The ligamentum nuchae is the cephalad continuation of the supraspinous ligament and has a prominent role in stabilizing the cervical spine.

Figure 1. Cervical spine

Figure 2. Cervical disc

Figure 3. Cervical facet joint (cervical zygapophyseal joint)

How do I know if I have whiplash?

Sometimes you can have no symptoms after a whiplash injury, but sometimes your symptoms can be severe. Pain from a whiplash injury often begins 6 to 12 hours after the injury. You may just feel uncomfortable on the day of the injury or accident and find that your pain, swelling and bruising increase over the following days.

Common symptoms of whiplash include:

• neck problems: pain, stiffness, swelling or tenderness
• difficulty moving your neck
• headaches, difficulty concentrating
• muscle spasms or weakness
• ‘pins and needles’, numbness or pain in your arms and hands or shoulders
• dizziness, vertigo, (a feeling you are moving or spinning) or tinnitus (ringing in your ears)
• difficulties swallowing or blurred vision

Your symptoms are likely to greatly improve or disappear within a few days to weeks. It may take longer for your symptoms to resolve completely and you might even experience some pain and neck stiffness for months after a whiplash injury.

How long does whiplash last?

Pain from a whiplash injury often begins 6 to 12 hours after the injury. Many people feel uncomfortable on the day of the injury or accident and find that pain, swelling and bruising increase over the following days.

Many people recover within a few days or weeks. For others it may take several months but sometimes it can last up to a year or more to experience substantial improvement in symptoms. Ongoing symptoms may vary in their intensity during the recovery period. This is normal.

You should see a doctor if you have had a motor vehicle accident or an injury that’s causing pain and stiffness in your neck.

The length of time it takes to recover from whiplash can vary and is very hard to predict.

Many people will feel better within a few weeks or months, but sometimes it can last up to a year or more.

Severe or prolonged pain can make it difficult to carry out daily activities and enjoy your leisure time. It may also cause problems at work and could lead to anxiety or depression.

Try to remain positive and focus on your treatment objectives. But if you do feel depressed, speak to your doctor about appropriate treatment and support.

What can I do to help my recovery?

Research has shown that it is better to try to keep doing normal daily activities as much as possible to aid recovery.

You need to take care of your neck and not expose it to unnecessary strain during the healing phase. It’s also important to regularly exercise your neck muscles. This booklet offers advice on how to care for your neck and suggests some specific exercises for your neck to help recovery.

Can I do the same activities as before?

Are there any limitations?

In the early stages of recovery, you may need to adapt some activities to care for your neck. However you should gradually resume normal activity as your neck improves (work, recreation and social).

Those who continue to work, even in a reduced capacity at first, have been shown to have a better recovery than people who take a long time off work.

An injury will cause pain. However the pain that occurs in the recovery period does not automatically mean that there is further injury. It is best to stay active and gently exercise to recover.

It may be necessary to limit some of your usual work and recreational activities in the early to mid-stage of recovery. Be adaptable – find new ways to do tasks to avoid unnecessary strain on your neck.

Whiplash causes

Whiplash injuries are commonly caused by car accidents. Whiplash can occur if your head is thrown forwards, backwards or sideways violently. For example if your neck is quickly accelerated and decelerated in a rear-end or side impact.

Common causes of whiplash include:

• road traffic accidents and collisions
• a sudden blow to the head – for example, during sports such as boxing or rugby
• a slip or fall where the head is suddenly jolted backwards
• being struck on the head by a heavy or solid object
• physical abuse or assault. Whiplash can occur if you are punched or shaken. It’s one of the injuries seen in shaken baby syndrome.

Studies with cadavers have shown the whiplash injury is the formation of the S-shaped curvature of the cervical spine which induced hyperextension on the lower end of the spine and flexion of the upper levels, which exceeds the physiologic limits of spinal mobility ³⁸. The Quebec task force (QTF) defined whiplash as bony or soft tissue injuries as a result of rear-end or side-impact in road traffic accidents, and from other injuries resulting in “an acceleration-deceleration mechanism of energy transfer to the cervical spine” ⁵. The Quebec task force proposed a classification system to define the severity of the whiplash injury. In Grade 1 the patient complains of neck pain, stiffness, or tenderness with no positive findings on physical exam. In Grade 2 the patient exhibits musculoskeletal signs including decreased range of motion and point tenderness. In Grade 3 the patient also shows neurologic signs that may include sensory deficits, decreased deep tendon reflexes, muscle weakness. Grade 4 the patient shows a fracture ⁵. Most whiplash-associated disorders are considered to be minor soft tissue-based injuries without evidence of fracture.

Whiplash signs and symptoms

The symptoms of Whiplash Injury often include pain, decreased mobility of the neck, tenderness, headaches and problems of concentration and memory.

Common symptoms of whiplash include:

• neck pain and stiffness
• swelling and tenderness in the neck
• temporary loss of movement, or reduced movement, in the neck
• headaches, most often starting at the base of the skull
• muscle spasms
• tenderness or pain in shoulder, upper back or arms
• tingling or numbness in the arms
• fatigue
• pain in the shoulders or arms.

Whiplash can also cause:

• lower back pain
• pins and needles, numbness or pain in the arms and hands (paresthesias)
• dizziness
• sleep disturbances
• tiredness and irritability
• difficulties swallowing (dysphasia)
• temporomandibular joint symptoms
• blurred vision
• memory problems
• vertigo (a feeling you are moving or spinning)
• difficulty concentrating
• irritability
• tinnitus (ringing in the ears)

Psychosocial symptoms ³⁹:

• depression
• anger
• frustration
• anxiety
• family stress
• occupational stress
• hypochondriasis (also known as health anxiety or illness anxiety disorder)
• compensation neurosis
• drug dependency
• post-traumatic stress syndrome (PTSD)
• litigation
• social isolation

You should see a doctor if you have neck pain after a car accident or after an injury.

Pain

Whiplash injury is a painful injury. As a result of the impact that caused the injury, there may be bruising or tearing of the soft tissues in the neck region, contributing to symptoms of pain. The pain of whiplash might be localized in the neck, or may also extend to the shoulders, and upper arms. Many individuals who have sustained whiplash injuries also report pain in the lower back region.

Decreased Mobility of the Neck

The uninjured neck has considerable mobility in several directions. The neck can move up and down (flexion-extension), side to side (lateral flexion) and can rotate (rotation). These movements are often restricted following a whiplash injury. There is a natural tendency for muscles to contract when the neck is painful. This contraction is the body’s way of trying to protect itself against further injury.

Tenderness of the Injured Area

Whiplash injury is considered to be an ‘overload’ injury. As a function of the excessive forces that impacted on the neck in the motor vehicle crash, elongation, bruising or tearing of the soft tissue can occur. In turn, the soft-tissue injuries can lead to inflammation and edema (e.g., swelling). Inflamed and swollen tissues are more ‘tender’ in that they are more sensitive to touch. Following a whiplash injury, areas of tenderness can include regions of the neck, shoulders and upper arms.

Headaches

Whiplash injury can also cause headaches. Headaches of whiplash injury may differ from tension or migraine headaches. Whiplash headaches, are more likely to occur at the top or the back of the head as opposed to regions around the eyes or the side of the head. Whiplash headaches can be intermittent or constant.

Memory and Concentration Problems

Individuals who have sustained whiplash injuries sometimes report problems with memory and concentration. If the head was struck during the crash that caused the whiplash injury, it is possible that the memory or concentration problems might be due to concussion. If the head was not struck, the memory and concentration problems are most likely due to the distracting effects of pain or anxiety.

Long term effects of whiplash

Most people who have whiplash injury feel better within a few weeks and don’t seem to have any lasting effects from the injury. However, some people continue to have pain for several months or years after the whiplash injury occurred.

It is difficult to predict how each person with whiplash may recover. In general, you may be more likely to have chronic pain if your first symptoms were intense, started rapidly and included:

• Severe neck pain
• More-limited range of motion
• Pain that spread to the arms

The following risk factors have been linked to a worse outcome:

• Having had whiplash before
• Older age
• Existing low back or neck pain
• A high-speed injury

Whiplash is an injury from which most individuals recover well. Studies have shown that people who are positive about recovery and resume their normal daily activities as tolerated may recover faster than those who markedly alter or markedly reduce their activity level for a period.

A small percentage of people who have a whiplash injury may develop long-term neck pain. Research is being conducted worldwide to understand why there are different recovery rates between different people. Some reasons have been identified such as age and initial severity of the pain or injury. However there is still more to be learnt.

The main symptoms of a whiplash associated disorder are neck pain and stiffness. Other symptoms such as headaches, aching in the arms or feelings of being lightheaded are common.

Symptoms may appear immediately after the incident or have a delayed onset of a few hours or days. The nature of injury and the number and severity of symptoms vary between different people.

Neck x-rays may be taken to rule out injuries such as bone fractures or dislocations. X-ray reports often state that no abnormality has been found. However, x-rays do not reveal injuries to the soft tissues of the neck (non bony parts of joints, ligaments, muscles) and x-rays do not provide information about pain levels. Normal x-rays only provide assurance that there are no major bone injuries.

Whiplash injury diagnosis

Questions about the event and your symptoms are the doctor’s first step for making a diagnosis. You also may be asked to fill out a brief form that can help your doctor understand the frequency and severity of your symptoms, as well as your ability to do normal daily tasks.

Examination

During the exam your doctor will need to touch and move your head, neck and arms. He or she will also ask you to move and perform simple tasks. This examination helps your doctor determine:

• The range of motion in your neck and shoulders
• The degree of motion that causes pain or an increase in pain
• Tenderness in the neck, shoulders or back
• Reflexes, strength and sensation in your limbs

Imaging tests

Your doctor will likely order one or more imaging tests to rule out other conditions that could be causing or contributing to neck pain. These include the following tests:

• X-rays of the neck. X-rays of the neck taken from multiple angles can identify fractures, dislocations or arthritis.
• Computerized tomography (CT). Computerized tomography (CT) is a specialized X-ray technology that can produce multiple cross-sectional images of bone and reveal details of possible bone damage.
• Magnetic resonance imaging (MRI). Magnetic resonance imaging (MRI) is a technology that uses radio waves and a magnetic field to produce detailed 3-D images. In addition to bone injuries, MRI scans can detect some soft tissue injuries, such as damage to the spinal cord, disks or ligaments.

Imaging techniques (e.g., magnetic resonance imaging or computerized tomography) and physiological methods are often unable to provide useful and unequivocal information in the instances of mild injuries ⁴⁰. In the past, the suggestion was to combine various investigation methods, such as imaging techniques and psychiatric, orthopedic, and neurological data, together with a detailed clinical history and evaluation, to draw a complete diagnostic picture of a patient and a realistic level of disability ⁴⁰. However, this kind of assessment is costly in terms of time and expenses related to the instruments, it requires the presence of specialists ⁴⁰, and, most importantly, does not necessarily exclude the presence of exaggerated symptoms.

Whiplash treatment

It is important to note that, although there are many different treatment options available for the management of whiplash injury, not all have been shown to be effective. It is also important to note that even though a certain treatment might have been shown to be effective, it might not be the right treatment for you.

The goals of whiplash treatment are to:

• Control pain
• Restore normal range of motion in your neck
• Get you back to your normal activities

It is best to have an in-depth discussion with your doctor, chiropractor or physiotherapist to determine the best treatments for the symptoms you are experiencing.

Your treatment plan will depend on the extent of your whiplash injury. Some people only need over-the-counter pain medication or nonsteroidal anti-inflammatory drugs (NSAIDs), a cervical collar, and at-home care. Others may need prescription medication (antidepressants, muscle relaxants) and specialized pain treatment in conjunction with physiotherapy or chiropractic care.

Soft foam cervical collars were once commonly used for whiplash injuries to hold the neck and head still. However, studies have shown that keeping the neck still for long periods of time can decrease muscle strength and interfere with recovery ⁴¹, ⁴², ⁴³. Still, using of a cervical collar to limit movement may help reduce pain soon after your injury, and may help you sleep at night. Recommendations for using a cervical collar vary though. Some experts suggest limiting cervical collar use to no more than 72 hours, while others say it may be worn up to three hours a day for a few weeks. Your doctor can instruct you on how to properly use the cervical collar, and for how long.

Pain management

Your doctor may recommend one or more of the following treatments to lessen pain ⁴⁴:

• Rest. Rest may be helpful during the first 24 hours after injury, but prolonged bed rest may delay recovery.
• Ice or heat. Apply ice or heat to the neck for 15 minutes up to six times a day.
• Over-the-counter pain medications. Over-the-counter pain relievers, such as acetaminophen (Tylenol, others) and ibuprofen (Advil, Motrin IB, others), often can control mild to moderate whiplash pain.
• Prescription painkillers. People with more-severe pain may benefit from short-term treatment with prescription pain relievers.
• Muscle relaxants. These drugs may control pain and help restore normal sleep if pain prevents you from sleeping well at night.
• Injections. An injection of lidocaine (Xylocaine) — a numbing medicine — into painful muscle areas may be used to decrease pain so that you can do physical therapy.

Individuals at high-risk of non-recovery should receive referral to a specialist clinician with expertise in the management of whiplash associated disorder ⁴⁵, ⁶.

How to treat whiplash

A number of treatments have been developed to manage the symptoms of whiplash injury. Some of the more common treatments described below include ⁴⁶:

• Advice to remain active
• Education
• Medication
• Physiotherapy
• Treatment of Mental Health Problems

Advice to Remain Active

Many doctor’s and physiotherapists will recommend to their patients that they try to remain as active as possible during the recovery period. While such advice might not appear to be much of a treatment, the advice is nevertheless a critical element in ensuring optimum recovery.

When people are injured and are experiencing pain and discomfort, there is a tendency to reduce one’s participation in important activities of daily life. As a result of pain or discomfort, individuals might reduce their participation in family or home activities, in recreational activities and individuals might also discontinue their occupational activities.

Reducing activity sometimes feels like the right thing to do because it is associated with a reduction in pain. But there lies the trap. Activity reduction is probably the worst thing to do in the management of a whiplash injury. While activity reduction might reduce pain and discomfort in the short term, in the long term, activity reduction will likely lead to more severe pain, and more severe disability.

Muscles need to move to remain healthy. Individuals who discontinue the important activities of their daily lives, or individuals who spend excessive time resting or lying down will actually recover more slowly. Slowing down a little bit makes sense during the initial days of recovery, but lying down or bed rest should be avoided. Remaining active is the best formula for optimal recovery.

Medication

The two most frequently prescribed medications for whiplash injury are anti-inflammatories and painkillers ⁴⁷. Following a whiplash injury, the soft-tissues of the neck and shoulders can become inflamed. Inflammation often leads to increased stiffness and pain. Anti-inflammatories reduce swelling of the injured soft tissues, and reduce pain as well. Inflammation is typically only present in the first few weeks following injury so anti-inflammatories tend not be used for long term pain management.

There are two main types of painkillers (analgesics) that might be prescribed for pain caused by whiplash injury. There are non-steroidal analgesics such as aspirin or paracetamol (acetaminophen), and there are opiate analgesics such as codeine. Painkillers can be useful treatments to manage the pain of whiplash injury in the short term, but long-term use is typically not recommended. Long-term use of acetaminophen (paracetamol) can cause stress on liver function. Long-term use of opiate analgesics can lead to gastro-intestinal problems, and of even more concern, these medications can lead to problems of addiction.

Education

It is becoming increasingly clear that education is an important element of the management of whiplash injury. A doctor or a physiotherapist might choose to spend some time explaining to a patient exactly what whiplash is and describe the pros and cons of different treatments.

One of the benefits of education is that it can help reduce anxiety. The experience of severe pain and symptoms of stiffness and headaches can be alarming. The injured person might think, ‘there must be something seriously wrong with my neck’, ‘if it hurts this much, there must be a lot of damage’, ‘when I move, it hurts more, so I should probably not move’. Thoughts like these will create anxiety or fear. In turn, anxiety and fear will lead the person to discontinue even more of their activities.

The doctor or physiotherapist might wish to educate the injured person about why he or she is experiencing a lot of pain, to explain that the symptoms of whiplash will recover over time, and to explain the importance of remaining as active as possible.

The doctor or physiotherapist might also wish to educate the injured person about the relation between pain and injury severity. We often assume that if the pain is severe, this must mean that the injury is severe. But with whiplash injury that is not the case. The pain of whiplash can be very severe, but that does not mean that severe or irreparable damage has been done to the neck. The majority of whiplash injuries are not considered ‘medically serious’; the pain might be initially severe, but the pain dissipates over time.

Exercise

Your doctor will likely prescribe a series of stretching and movement exercises for you to do at home. These exercises can help restore range of motion in your neck and get you back to your normal activities ⁴⁸, ⁴⁹, ⁵⁰. Applying moist heat to the painful area or taking a warm shower may be recommended before exercise.

Exercises may include (see more below):

• Rotating your neck in both directions
• Tilting your head side to side
• Bending your neck toward your chest
• Rolling your shoulders

Physical therapy

Physical therapy is another commonly used approach to treating whiplash injury. If you have ongoing whiplash pain or need assistance with range-of-motion exercises, your doctor may recommend that you see a physical therapist. A physical therapist might use a variety of treatment techniques to manage the symptoms of whiplash. Initially, the physiotherapist might use modalities such as manual therapy or ice to reduce the swelling and inflammation of the injured areas. The physical therapist will also provide the injured person with exercises to improve or maintain the movement in their neck as well as strength and control of the muscles in their neck and upper body and to restore normal movement. This in turn will help increase the person’s tolerance for participation in household, recreational and occupational activities.

As the injured person begins to be more physically active, it sometimes happens that their pain and discomfort might increase. This increase in pain is usually caused by engaging muscles that have remained inactive or immobile for extended periods of time. The pain associated with increasing activity is temporary and will usually subside in a day or two.

In some cases, transcutaneous electrical nerve stimulation (TENS) may be used. TENS applies a mild electric current to the skin. Limited research suggests this treatment may temporarily ease neck pain and improve muscle strength.

The number of physical therapy sessions needed will vary from person to person. Your physical therapist can also create a personalized exercise routine that you can do at home.

Treatment of Mental Well Being

Some individuals with whiplash injuries might develop symptoms of a mental health problem. The most common mental health problems associated with whiplash injury include depression, anxiety and post-traumatic stress symptoms. If an injured person is experiencing troubling symptoms of depression, anxiety or post-traumatic symptoms, the doctor might consider prescribing medication such as an anti-depressant or anti-anxiety medication. Since the presence of symptoms of a mental health problem can slow the rate of recovery following whiplash injury, these medications can play an important role in the successful management of whiplash injury.

If you have developed symptoms of a mental health problem following your whiplash injury, your doctor might also consider a referral to a mental health professional such as a psychologist or a social worker. Psychologists and social workers can provide counselling or psychotherapy that can be useful in managing some of the mental health consequences of whiplash injury. Your doctor can familiarize you with the mental health services that are available in your community.

Alternative medicine

There are many other types of treatments that have been tried to treat whiplash pain, but research about how well they work is limited ⁵¹, ⁵², ⁵³, ⁵⁴, ⁵⁵. Some of these include manipulation, acupuncture, electrical nerve stimulation, traction, biofeedback, ultrasound among many others ⁵⁶, ⁵⁷.

• Acupuncture. Acupuncture involves inserting ultrafine needles through specific areas on your skin. It may offer some relief from neck pain.
• Chiropractic care. A chiropractor performs joint manipulation techniques. There is some evidence that chiropractic care may provide pain relief when paired with exercise or physical therapy.
• Neck massage. Neck massage may provide short-term relief of neck pain from whiplash injury.
• Mind-body therapies. Exercises that incorporate gentle movements and a focus on breathing and mindfulness, such as tai chi, qi gong and yoga, may help ease pain and stiffness.

It is difficult to make strong statements about the utility of these treatments since so little research has examined whether they are effective. Injured individuals who are slow to recover might reach a level of desperation where they are willing to try anything. It is important to remember that unless a treatment has been shown to be effective in a clinical trial, there is always the possibility that the treatment might not be helpful, or could actually worsen the condition. Before starting any treatment for your whiplash injury, it is best to discuss with a doctor or medical specialist the treatment options that are most appropriate for your condition.

Home remedies for whiplash injury

You are your own best resource in the recovery process. Managing yourself is a key part to stopping the discomfort that you are experiencing. Staying active is important. Do as many of your normal activities as possible. Some more vigorous activities that place undue stresses on your neck may need to be avoided in the early stages of recovery.

However, better recovery has been found in individuals who continue a healthy active routine after a whiplash injury. This goes for your general health as well as that of your neck.

Plan gradual increases in activity and exercise levels so that you can successfully return to full participation in your regular activities, hobbies or sports.

Continue or resume working

Those who continue to work, even in a reduced capacity at first, have been shown to have a better recovery than people who take a long time off work. It may be necessary to change some work routines for a while.

You may wish to talk to your employer or health care practitioner regarding ways to modify your particular work tasks and environment if difficulties continue.

Keeping a good relationship with your employer and co-workers is helpful in the recovery process. Talk to your employer openly and frequently.

During times of high work load or busy periods, it is important to let colleagues and supervisors know that you may need extra time or help to meet deadlines. Don’t be afraid to ask for help. You may be in a position to return the favor at some time.

Maintain the flexibility and muscle support of your neck

An exercise program that is specific to the neck and upper back will greatly benefit your recovery. The exercise program in this booklet will help you regain normal neck movement and function.

The exercises are also designed to ensure that your neck receives proper support from the muscles.

Perform daily activities in a strain-free way

Thinking about how you do your work and recreational activities can avoid unnecessary strain on your neck, reduce pain and positively assist recovery.

Be aware of neck positions and postures at work and home

Keeping your spine in a good position is important in everyday activities as well as during the exercises.

The positions in which you work and relax each day have a great impact on the health of your spine. It is easy to compensate and allow yourself to develop poor postural habits. You will need to be consciously aware of postures and positions when you are performing tasks at home and work.

Postural correction exercise

Correct your posture by gently growing tall from the lower back and pelvic region (see Figure 1 below).

Gently raise your pelvis up out of a slumped position.

Next, reposition your shoulder blades so they draw back and across your rib cage (towards the center of your spine). This needs only minimal effort.

Gently lift the base of your skull off the top of your neck. This takes the weight of your head off your neck and stimulates the muscles to work.

Hold the position for at least 10 seconds. Repeat frequently during the day (e.g. three or four times an hour).

Perform this exercise when sitting, standing or while walking, at work and at home.

Figure 4. Whiplash injury exercises

Range of motion exercises

For each of the following exercises, complete 5-10 repetitions in each direction.

Neck rotation exercise

Assume the correct postural position. Gently turn your head to the left, looking where you are going to see over your shoulder as much as possible.

You may find it easier to have a target on the wall to focus on.

With each repetition, try to go a little further in that direction. Perform the same exercise to the right side.

Figure 5. Neck rotation exercise

Neck side bending exercise

Assume the correct postural position. Start with your head centered and gently bring your right ear down towards your right shoulder. You may feel a normal stretch of the muscles on the side of your neck. The exercise should be pain-free. Perform this exercise on the left side.

Figure 6. Neck side bending exercise

Forward and backward bending

Assume the correct postural position.

Figure 7. Neck forward and backward bending exercise

Exercises to retrain muscle control

Head nod and holding exercise

This is an important exercise to retrain the deep neck muscles of the front of your neck for pain relief and muscle control.

Lie on your back with knees bent without a pillow under your head and neck.

A. If this is not comfortable, place a small, folded towel under your head for support.

B. Start by looking up at a point on the ceiling. Then with your eyes, look at a spot on the wall just above your knees. Feel the back of your head slide up the bed as you perform a slow and gentle nod as if you were indicating ‘yes’.

While doing the exercise, place your hand gently on the front of the neck to feel the superficial muscles. Make sure they stay soft and relaxed when doing the head nod movement. Stop at the point you sense the muscles are beginning to harden, but keep looking down with your eyes.

Hold the position for 10 seconds and then relax. Look up to a point on the ceiling to resume the starting position. Repeat the exercise 10 times.

Figure 8. Head nod and holding exercise

Head and neck exercises

These are important exercises to retrain the muscles at the back of your neck for pain relief and muscle control. There are three exercises to perform, which ensures you exercise the upper and lower regions of your neck.

Lie on your stomach, propped up on your elbows. Push through your elbows to prevent your chest from sagging between your shoulder blades.

To begin, perform each exercise five times as one set. Try to build up to three sets (and eventually three sets of 10 repetitions each). Remember to keep pushing through your elbows to keep your chest raised for the whole set. Have a rest between sets.

Figure 9. Head and neck exercises

Shoulder blade exercises

Poor muscle control around the shoulder blades can increase pain and strain on the neck. There are three exercises that you can do for your shoulder blades and arms.

This first exercise will relax and ease any tension in the muscles on top of your shoulders. It can give you pain relief.

Figure 10. Shoulder blade exercises

The second exercise helps you to improve the control of your shoulder blades while mimicking work you may do with your arms. It trains you to ease any tension in the muscles on top of your shoulders while you are using your arms.

Sit and correct your posture and draw your shoulder blades back and across your rib cage as you have already practised.

Concentrate on holding your shoulder blade position. Then move your arms:

• (A) forwards and backwards;
• (B) out to the side; and
• (C) turn your forearms outwards.

Do not lift your arms more than 30 degrees in exercises A and B (that is, about a quarter of the way up). Perform each exercise (A,B and C) five times and repeat this set three times.

When you feel confident that you can do the exercise keeping your shoulder blades gently back, hold a 250 gram can in each hand as a small weight.

Figure 11. Shoulder blade exercises part 2

The third exercise is simply raising alternate arms forward as far up as you can go. Make sure that you maintain a good posture, especially concentrating on lifting the base of your skull off the top of your neck and then as you raise your arm, keep your thumb facing upwards. Perform three sets of five left and right arm raises.

Figure 12. Shoulder blade exercises part 3

Neck isometric exercise (no movement)

Assume the correct postural position and gently raise the back of your head. Place your right hand on the right cheek. Without moving your head, turn your eyes to the right and gently push your head into your hand as if to look over your shoulder. While performing this exercise no movement occurs. Hold the muscle contraction for five seconds.

Do the exercise smoothly and gently, use only 10% effort.

Change hand position and perform the same exercise to the left side. Do five repetitions on each side.

Figure 13. Neck isometric exercise

Once your neck pain has settled, the exercises can be progressed to include strengthening exercises.

These exercises should not cause pain. Progress slowly.

Head lift exercise

The weight of your head is enough weight to lift. Start by sitting on a chair close to a wall. Rest your head back on the wall.

Slide the back of your head up the wall to nod your chin and hold it in this position. Then just take the weight of your head off the wall (your hair still touches the wall). Hold for five seconds and relax.

Start by doing three sets of two to three repetitions and gradually build up to three sets of five repetitions.

Shifting the chair a little further from the wall makes the exercise more difficult.

You can progress the exercise by moving the chair away from the wall in five centimeter stages.

Figure 14. Head lift exercise

Progression: Lie resting your head on two pillows.

Slide the back of your head up the pillow to nod your chin and hold it in this position. Then try to just lift the weight of your head until it just clears the pillow.

Hold for five seconds and relax. Start by doing three sets of two to three repetitions and gradually build up to three sets of five repetitions.

The exercise can be progressed by removing one pillow and performing the exercise in the same way.

Figure 15. Head lift exercise (progression)

Sitting

Sitting in one position for prolonged periods is not good for anyone, certainly not someone with neck pain.

Change your position

Sitting in one position for prolonged periods is not good for anyone, certainly not someone with neck pain. Keep your neck healthy and move often.

It is essential that you change your position before your neck becomes stiff or sore. Perform the postural correction exercise regularly. Stand up and move regularly, at least every hour.

Assess how you spend your day at work

Whether sitting in a motor vehicle, at a desk or computer terminal, you need to give your body a regular change of position throughout the day. Take a ‘neck break’, it can be as simple as standing up for a few moments to straighten your spine. Stand and stretch backwards gently to reverse the flexed sitting posture. A complete change of position every hour is advisable.

Working at a computer

Arrange your desk, chair and computer to avoid strain on your neck (see Figure 2). Have work materials close to you and in easy reach.

• A. Position the top of your screen slightly below eye level and directly in front of you (50-70cm or arm’s length away). There is no single monitor height suitable for everyone. Position the screen to have a comfortable viewing angle to the middle of the screen. Avoid extremes of head and neck bending (upwards or downwards).
• B. Have an adjustable chair so that you can change the height and angle of the back support. Have the chair close to the desk so you do not have to reach for the keyboard or mouse. If possible, rest your forearms on the desktop to ‘unload’ the shoulders.
• C. Desk height should allow sitting with shoulders and arms relaxed with elbows at a 90 degree angle and wrists in a neutral position. Sit with hips and knees at close to 90 degree angles. Feet should be flat on the floor or use a foot stool to achieve a comfortable position.
• D. If working from documents for prolonged periods, these should be placed on a document holder either positioned between the keyboard and monitor or at the same eye level as the screen and close to the monitor. Reading from items placed flat on the desktop may increase the strain on your neck and should be avoided. Books and documents should be elevated onto a sloped surface (e.g. an empty 2-ring folder).
• E. When using the computer mouse, keep the mouse close to the keyboard, use keyboard shortcuts instead of the mouse and alternate which hand uses the mouse.

Current research suggests that spending time standing at work (high set work station) has benefits not only for the neck and back, but also for general health (e.g. by increasing daily activity levels to help maintain healthy body weight). At home and work, try to spend time working in a standing position.

Figure 16. Working at a computer

Whiplash prognosis

Most people with whiplash get better within a few weeks by following a treatment plan that includes pain medication and exercise. However, some people have chronic neck pain and other long-lasting complications. Recovery following whiplash injury, if it is to occur, will occur for the most part within the first 3 months post injury ¹⁷. Current estimates suggest that approximately 50% of individuals will recover by 3 months post injury, whilst the remainder will experience mild to moderate long-term disability ¹⁸, ¹⁹, ²⁰.

Whiplash prognosis varies secondary to comorbidities prior to the injury, severity of whiplash-associated disorders, age, the legal environment and socioeconomic environment ⁸. Full recovery has been shown to occur in a few days to several weeks ⁵⁸. However, disability can be permanent and range from chronic pain to impaired physical function ⁵⁸. There have been inadequate studies that incorporate mitigating factors, such as socioeconomic and legal, which can impact an accurate assessment of recovery ⁸. Legal environment, prior injury, comorbidity, age, and defensive medicine all play roles in the management and outcomes ⁵⁸. In countries where there is little or no litigation, whiplash prognosis is more favorable lending that economic gain for disability may play a role in determining the patient’s reports of full recovery ⁵⁸. For example, in countries such as Lithuania and Greece, where there is no compensation culture and no formal compensation system for late whiplash-related injuries, the development of chronic symptoms following whiplash is a rare phenomenon ²³, ²⁴. This evidence suggests that the culture and expectations around whiplash, local insurance systems, and the prospect of monetary benefits are likely to play important roles in the prevalence of whiplash injuries and related claims, as well as in the recovery process ²⁵. In Germany, for instance, whiplash-associated disorders represent the most common consequence of road traffic accidents, counting approximately 20,000 cases each year and costing insurance companies more than 500 million euro annually ²⁴. Similarly, in Italy, it is estimated that the compensation for whiplash-related damages amounts to more than 2 million euro every year ⁵⁹.

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Human skeletal system

The skeletal system includes the bones of the skeleton and the cartilages, ligaments, and other connective tissues that stabilize or interconnect them. Bones are the organs of the skeletal system, and they do more than serve as racks that muscles hang from; they support your weight and work together with muscles, producing controlled, precise movements. Without a framework of bones to connect to, contracting muscles would just get shorter and fatter. Our muscles must pull against the skeleton to make you sit, stand, walk, or run.

The bones of the skeleton are complex, dynamic organs that contain osseous tissue, other connective tissues, smooth muscle tissue, and neural tissue.

The skeleton has many vital functions:

• Support: The skeletal system provides structural support for the entire body. Individual bones or groups of bones provide a framework for the attachment of soft tissues and organs and muscles use to cause movement.
• Mineral storage: The calcium salts of bone are a valuable mineral reserve that maintains normal concentrations of calcium and phosphate ions in body fluids. Calcium is the most abundant mineral in the human body. A typical human body contains 1–2 kg (2.2–4.4 lb) of calcium, with more than 99 percent of it in the bones of the skeleton.
• Blood cell production: Within certain bones, a connective tissue called red bone marrow produces red blood cells, white blood cells, and platelets, a process called hemopoiesis. Red bone marrow consists of developing blood cells, adipocytes, fibroblasts, and macrophages within a network of reticular fibers. It is present in developing bones of the fetus and in some adult bones, such as the hip (pelvic) bones, ribs, sternum (breastbone), vertebrae (backbones), skull, and ends of the bones of the humerus (arm bone) and femur (thigh bone). In a newborn, all bone marrow is red and is involved in hemopoiesis. With increasing age, much of the bone marrow changes from red to yellow.
• Triglyceride storage. Yellow bone marrow consists mainly of adipose cells, which store triglycerides. The stored triglycerides are a potential chemical energy reserve.
• Protection: Skeletal system protects and supports body organs and delicate tissues. The ribs protect the heart and lungs, the skull encloses the brain, the vertebrae shield the spinal cord, and the pelvis cradles delicate digestive and reproductive organs.
• Leverage: Many bones of the skeleton function as levers. They change the magnitude and direction of the forces generated by skeletal muscles. The movements produced range from the delicate motion of a fingertip to powerful changes in the position of the entire body.

Bones in human body

The skeleton is divided into two regions:

1. The Axial skeleton and
2. Appendicular skeleton.

The axial skeleton, which forms the central supporting axis of the body, includes:

• the skull,
• auditory ossicles,
• hyoid bone,
• vertebral column, and
• thoracic cage (ribs and sternum).

The appendicular skeleton includes:

• the bones of the upper limb and
• pectoral girdle and the bones of the lower limb and pelvic girdle.

Bones of the Skeletal System

It is often stated that there are 206 bones in the skeleton, but this is only a typical adult count, not an invariable number. At birth there are about 270, and even more bones form during childhood. With age, however, the number decreases as separate bones gradually fuse. For example, each side of a child’s pelvic girdle has three bones—the ilium, ischium, and pubis—but in adults, these are fused into a single hip bone on each side. The fusion of several bones, completed by late adolescence to the mid-20s, brings about the average adult number of 206.

This number varies even among adults. One reason is the development of sesamoid bones—bones that form within some tendons in response to strain. The patella (kneecap) is the largest of these; most of the others are small, rounded bones in such locations as the hands and feet. Another reason for adult variation is that some people have extra bones in the skull called sutural bones.

Figure 1. Human skeleton

Note: Green colored bones are Appendicular skeleton. The rest are Axial skeleton.

Figure 2. Skull bone

Figure 3. Cervical vertebrae

Figure 4. Vertebral column

Figure 5. Thoracic bones

Figure 6. Lumbar spine and pelvis

Figure 7. Hand and wrist bones

Figure 8. Foot bones

Structure and Function of Bone

Structure of Bone

A typical long bone consists of the following parts:

1. The diaphysis is the bone’s shaft or body—the long, cylindrical, main portion of the bone.
2. The epiphyses (singular is epiphysis) are the proximal and distal ends of the bone.
3. The metaphyses (singular is metaphysis) are the regions between the diaphysis and the epiphyses. In a growing bone, each metaphysis contains an epiphyseal (growth) plate, a layer of hyaline cartilage that allows the diaphysis of the bone to grow in length. When a bone ceases to grow in length at about ages 14–24, the cartilage in the epiphyseal plate is replaced by bone; the resulting bony structure is known as the epiphyseal line.
4. The articular cartilage is a thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation (joint) with another bone. Articular cartilage reduces friction and absorbs shock at freely movable joints. Because articular cartilage lacks a perichondrium and lacks blood vessels, repair of damage is limited.
5. The periosteum is a tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage. It is composed of an outer fibrous layer of dense irregular connective tissue and an inner osteogenic layer that consists of cells. Some of the cells enable bone to grow in thickness, but not in length. The periosteum also protects the bone, assists in fracture repair, helps nourish bone tissue, and serves as an attachment point for ligaments and tendons. The periosteum is attached to the underlying bone by perforating fibers or Sharpey’s fibers, thick bundles of collagen that extend from the periosteum into the bone extracellular matrix.
6. The medullary cavity or marrow cavity, is a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow and numerous blood vessels in adults. This cavity minimizes the weight of the bone by reducing the dense bony material where it is least needed. The long bones’ tubular design provides maximum strength with minimum weight.
7. The endosteum is a thin membrane that lines the medullary cavity. It contains a single layer of bone-forming cells and a small amount of connective tissue.

Figure 9. Parts of a long bone

Note: The spongy bone tissue of the epiphyses and metaphyses contains red bone marrow, and the medullary cavity of the diaphysis contains yellow bone marrow (in adults).

The Cells of Mature Bone

Bone contains four cell types: osteoblasts, osteocytes, osteoprogenitor cells, and osteoclasts.

Osteocytes

Mature bone cells are osteocytes. They maintain and monitor the protein and mineral content of the surrounding matrix. The minerals in the matrix are continually recycled. Each osteocyte directs the release of calcium from bone into blood and the deposition of calcium salts into the surrounding matrix. Osteocytes occupy small chambers, called lacunae, that are sandwiched between layers of calcified matrix. These matrix layers are called lamellae (singular, lamella) (Figure 10 b–d). Channels called canaliculi (“little canals”) radiate through the matrix from lacuna to lacuna and toward free surfaces and adjacent blood vessels. The canaliculi connect adjacent lacunae and bring the processes of neighboring osteocytes into close contact. Tight junctions interconnect these processes and provide a route for the diffusion of nutrients and waste products from one osteocyte to another across gap junctions.

Osteoblasts

Cuboidal cells found in a single layer on the inner or outer surfaces of a bone are called osteoblasts (precursor). These cells secrete the organic components of the bone matrix. This material, called osteoid, later becomes mineralized through a complicated, multistep mechanism. Osteoblasts are responsible for the production of new bone—a process called osteogenesis. It is thought that osteoblasts respond to a variety of different stimuli, including mechanical and hormonal, to initiate osteogenesis. If an osteoblast becomes surrounded by matrix, it differentiates into an osteocyte.

Osteoprogenitor Cells

Bone tissue also contains small numbers of stem cells termed osteoprogenitor cells (ancestor). Osteoprogenitor cells differentiate from mesenchyme and are found in numerous locations, including the innermost layer of the periosteum and the endosteum lining the medullary cavities. Osteoprogenitor cells divide to produce daughter cells that differentiate into osteoblasts. The ability to produce additional osteoblasts becomes extremely important after a bone is cracked or broken.

Osteoclasts

Large, multinucleate cells found at sites where bone is being removed are termed osteoclasts. They are derived from the same stem cells that produce monocytes and neutrophils. They secrete acids through a process involving the exocytosis of lysosomes. The acids dissolve the bony matrix and release amino acids and the stored calcium and phosphate. This erosion process, called osteolysis, increases the calcium and phosphate concentrations in body fluids. Osteoclasts are always removing matrix and releasing minerals, and osteoblasts are always producing matrix that quickly binds minerals. The balance between the activities of osteoblasts and osteoclasts is very important; when osteoclasts remove calcium salts faster than osteoblasts deposit them, bones become weaker. When osteoblasts are more active than osteoclasts, bones become stronger and more massive. New research indicates that osteoclasts may also be involved in osteoblast
differentiation, immune system activation, and the proliferation of tumor cells in bone.

Figure 10. Microscopic Structure of a Typical Bone

Organization of Mature Bone

The Matrix of Bone

Calcium phosphate, accounts for almost two-thirds of the weight of bone. It interacts with calcium hydroxide to form crystals of hydroxyapatite. As these crystals form, they incorporate other calcium salts, such as calcium carbonate, and ions such as sodium, magnesium, and fluoride. This process, called calcification is initiated by bone-building cells called osteoblasts. Calcification requires the presence of collagen fibers. Mineral salts first begin to crystallize in the microscopic spaces between collagen fibers. After the spaces are filled, mineral crystals accumulate around the collagen fibers. The combination of crystallized salts and collagen fibers is responsible for the characteristics of bone. These inorganic components enable bone to resist compression. Roughly one-third of the weight of bone is from collagen fibers and other noncollagenous proteins, which give bone considerable tensile strength.

Osteocytes and other cell types account for only 2 percent of the mass of a typical bone. Calcium phosphate crystals are very strong, but relatively inflexible. They with stand compression, but the crystals shatter when exposed to bending, twisting, or sudden impacts. Collagen fibers are tough and flexible. They easily tolerate stretching, twisting, and bending but, when compressed, they simply bend out of the way. In bone, the collagen fibers and other noncollagenous proteins provide an organic framework for the formation of mineral crystals. The hydroxyapatite crystals form small plates that lie alongside these ground substance proteins. The result is a protein–crystal combination with properties intermediate between those of collagen and those of pure mineral crystals.

Compact and Spongy Bone

There are two types of osseous tissue: compact bone and spongy bone. Compact bone is relatively dense and solid, whereas spongy bone, also termed trabecular bone or cancellous bone, forms an open network of struts and plates. Both are found in typical bones of the skeleton, such as the humerus, the proximal bone of the upper limb, and the femur, the proximal bone of the lower limb. Compact bone forms the walls, and an internal layer of spongy bone surrounds the medullary
(marrow) cavity. The medullary cavity contains bone marrow, a loose connective tissue that is dominated by either adipocytes (yellow marrow) or a mixture of mature and immature red and white blood cells and the stem cells that produce them (red marrow). Yellow marrow, often found in the medullary cavity of the shaft, is an important energy reserve. Extensive areas of red marrow, such as in the spongy bone of the femur, are important sites of blood cell formation.

Structural Differences between Compact and Spongy Bone

Compact and spongy bone have the same matrix composition, but they differ in the three-dimensional arrangement of the osteocytes, canaliculi, and lamellae.

Figure 11. Internal organization of bones

Compact Bone

Compact bone tissue contains few spaces and is the strongest form of bone tissue. It is found beneath the periosteum of all bones and makes up the bulk of the diaphyses of long bones. Compact bone tissue provides protection and support and resists the stresses produced by weight and movement.

Compact bone tissue is composed of repeating structural units called osteons, or haversian systems. Each osteon consists of concentric lamellae arranged around an osteonic (haversian or central) canal. Resembling the growth rings of a tree, the concentric lamellae are circular plates of mineralized extracellular matrix of increasing diameter, surrounding a small network of blood vessels and nerves located in the central canal. These tubelike units of bone generally form a series of parallel cylinders that, in long bones, tend to run parallel to the long axis of the bone. Between the concentric lamellae are small spaces called lacunae (little lakes; singular is lacuna), which contain osteocytes. Radiating in all directions from the lacunae are tiny canaliculi (small channels), which are filled with extracellular fluid. Inside the canaliculi are slender fingerlike processes of osteocytes.

Neighboring osteocytes communicate via gap junctions. The canaliculi connect lacunae with one another and with the central canals, forming an intricate, miniature system of interconnected canals throughout the bone. This system provides many routes for nutrients and oxygen to reach the osteocytes and for the removal of wastes.

Osteons in compact bone tissue are aligned in the same direction and are parallel to the length of the diaphysis. As a result, the shaft of a long bone resists bending or fracturing even when considerable force is applied from either end. Compact bone tissue tends to be thickest in those parts of a bone where stresses are applied in relatively few directions. The lines of stress in a bone are not static. They change as a person learns to walk and in response to repeated strenuous physical activity, such as weight training. The lines of stress in a bone also can change because of fractures or physical deformity. Thus, the organization of osteons is not static but changes over time in response to the physical demands placed on the skeleton.

The areas between neighboring osteons contain lamellae called interstitial lamellae, which also have lacunae with osteocytes and canaliculi. Interstitial lamellae are fragments of older osteons that have been partially destroyed during bone rebuilding or growth. Blood vessels and nerves from the periosteum penetrate the compact bone through transverse interosteonic (Volkmann’s or perforating) canals. The vessels and nerves of the interosteonic canals connect with those of the medullary cavity, periosteum, and central canals. Arranged around the entire outer and inner circumference of the shaft of a long bone are lamellae called circumferential lamellae. They develop during initial bone formation. The circumferential lamellae directly deep to the periosteum are called external circumferential lamellae. They are connected to the periosteum by perforating (Sharpey’s) fibers. The circumferential lamellae that line the medullary cavity are called internal circumferential lamellae.

Spongy Bone

The major difference between compact and spongy bone is the arrangement of spongy bone into parallel struts or thick, branching plates called trabeculae (also termed spicules). Numerous interconnecting spaces occur between the trabeculae in spongy bone. Spongy bone possesses lamellae, and if the trabeculae are thick enough, osteons will be present. In terms of the associated cells and the structure and composition of the lamellae, spongy bone is no different from compact bone. Spongy bone forms an open framework and as a result it is much lighter than compact bone. However, the branching trabeculae give spongy bone considerable strength despite its relatively light weight. Thus, the presence of spongy bone reduces the weight of the skeleton and makes it easier for muscles to move the bones. Spongy bone is found wherever bones are not stressed heavily or where stresses arrive from many directions.

Functional Differences between Compact and Spongy Bone

A layer of compact bone covers the surface of all bones. The thickness of this layer varies from region to region and from one bone to another, but compact bone is thickest where stresses arrive from a limited number of directions. This superficial layer of compact bone is in turn covered by the periosteum, a connective tissue wrapping that is connected to the deep fascia. The periosteum is complete everywhere except within a joint, where the edges or ends of two bones contact one another.

The shaft of compact bone transfers stresses from one epiphysis to another. For example, when you are standing, the shaft of the femur transfers your body weight from your hip to your knee. The osteons within the shaft are parallel to its long axis, and as a result the femur is very strong when stressed along that axis. Imagine a single osteon as a drinking straw with very thick walls. When you push the ends of a straw together, it seems quite strong. However, when you hold the ends and push the side of the straw, it breaks easily. Similarly, a long bone does not bend when forces are applied to either end, but an impact to the side of the shaft can easily cause a break, or fracture.

Spongy bone is not as massive as compact bone, but it is much more capable of resisting stresses applied from many different directions. The epiphyses of the femur are filled with spongy bone, and the alignment of the trabeculae within the proximal epiphysis. The trabeculae are oriented along the stress lines, but with extensive cross-bracing. At the proximal epiphysis, the trabeculae transfer forces from the hip across the metaphysis to the femoral shaft; at the distal epiphysis, the trabeculae transfer the forces across the knee joint to the leg. In addition to reducing weight and handling stress from many directions, the open trabecular framework supports and protects the cells of the bone marrow.

Blood and Nerve Supply to Bones

Like any living tissue, bones need nourishment. Osseous tissue is very vascular, and the bones of the skeleton have an extensive blood supply. In a long bone such as the humerus, four major sets of blood vessels develop:

1. The nutrient artery and nutrient vein: These vessels form as blood vessels invade the cartilage model at the start of endochondral ossification. There is usually only one nutrient artery and one nutrient vein entering the diaphysis through a nutrient foramen. A foramen (plural, foramina) is an opening in a bone. However, a few bones, including the femur, have two or more nutrient arteries. These vessels penetrate the shaft to reach the medullary cavity. The nutrient artery divides into ascending and descending branches, which approach the epiphyses. These vessels then re-enter the compact bone through perforating canals and extend along the central canals to supply the osteons of the compact bone.
2. Metaphyseal vessels: These vessels supply blood to the inner (diaphyseal) surface of each epiphyseal cartilage, where bone is replacing cartilage.
3. Epiphyseal vessels: The epiphyseal ends of long bones contain numerous smaller foramina. Epiphyseal vessels enter the bone through these foramina to supply the osseous tissue and medullary cavities of the epiphyses.
4. Periosteal vessels: Blood vessels from the periosteum are incorporated into the developing bone surface. These vessels provide blood to the superficial osteons of the shaft. During endochondral ossification, branches of periosteal vessels enter the epiphyses, bringing blood to the secondary ossification centers. After the epiphyses close, all of these blood vessels become extensively interconnected. The periosteum also contains an extensive network of lymphatic vessels and sensory nerves. The lymphatic vessels collect lymph (fluid derived from the interstitial fluid) from branches that enter the bone and reach individual osteons through perforating canals. The sensory nerves penetrate the compact bone with the nutrient artery to innervate the endosteum, medullary cavity, and epiphyses. Because of this rich sensory innervation, injuries to bones are usually very painful.

Figure 12. Blood supply to a Mature Bone