CLINICAL FEATURES

The diagnosis of RSD can be difficult to make and is based primarily on history and examination. Clinical manifestations can be variable, but persistent burning pain that develops after an injury is the characteristic feature. Three stages (acute, dystrophic, and atrophic) are often described. The acute stage lasts up to 6 to 12 weeks and is characterized by the development of persistent burning pain. The injury is often trivial, but the pain is characteristically severe and out of proportion to the amount of trauma. Initially, the pain is localized to the area of the injury, but gradually it spreads throughout the extremity. Hypersensitivity to light touch is a frequent symptom. The extremity appears swollen and warm, and excessive perspiration may be present. In the later dystrophic and atrophic stages, motion in the affected joints becomes restricted, and the involved area becomes cool. Skin and muscle atrophy develop, and the skin appears dry, shiny, and glossy. Stiffness and intractable pain may persist for several weeks or months. RSD is commonly associated with anxiety and depression.

Although no imaging studies are diagnostic, plain roentgenograms may eventually reveal patchy osteoporosis (Fig. 18-1). The bone scan may be positive, showing regional uptake that is diagnostic and reflects increased blood flow.

FIG. 18-1 Roentgenogram of the ankle several weeks after a relatively minor sprain. Severe osteoporosis (Sudeck’s bone atrophy) of the lower portions of the tibia and fibula are present.

TREATMENT

RSD is best treated by prevention. All injuries should have immediate attention, and pain and swelling should be controlled. Early use of the extremity is also important. Once RSD develops, it is very difficult to treat. The most important aspect of therapy is restoration of motion by exercise. Active use of the extremity should be encouraged despite the pain. The edema may be controlled by elevation. Physical therapy in the form of passive range-of-motion exercises may be helpful but should not replace active home exercise by the patient. Smoking should be discouraged. Among the pharmacologic agents sometimes effective are antidepressants, corticosteroids, and calcium channel blockers. Repeated sympathetic blocks are sometimes helpful. The treatment is often prolonged, but most patients eventually improve.

IN-TOEING

The in-toeing gait pattern seen in young children is the most common rotational deformity and is usually secondary to one or more of the following causes: (1) internal rotation deformity of the hip secondary to contracture or excessive femoral anteversion, (2) internal (medial) torsion of the tibia, or (3) metatarsus varus (adductus) of the foot. In-toeing is usually the result of metatarsus adductus in the infant, internal tibial torsion in the toddler, and increased femoral torsion in the child over the age of 10.

All three of these deformities are aggravated by positions or postures that are frequently assumed by the child or infant. Lying in the prone position with the legs extended and the feet internally rotated is often associated with in-toeing deformity. Sitting in the “reverse-tailor” position with the feet internally rotated beneath the buttocks is directly related to persistent tibial rotation and adduction of the forefoot (Fig. 18-2). Children may assume these positions for extended periods of time while sleeping, playing, or watching television.

FIG. 18-2 The reverse-tailor position.

Children with internal rotation deformities have a high incidence of bowing of the lower extremities. This is frequently more apparent than actual, because the lower limb is never visualized in the true anteroposterior plane but rather in the oblique plane. The gait is occasionally clumsy, and the appearance may be unsightly.

INTERNAL FEMORAL TORSION

The diagnosis is made by clinical examination. It is helpful to mark the patellae and observe their position as the child walks. If the child toes in and the patellae face medially, excessive femoral anteversion or an internal rotation contracture of the hips should be suspected. If the child toes in and the patellae face straight forward, then the deformity has to be distal to the knee, either internal tibial torsion or metatarsus varus. Internal femoral torsion can also be measured with the patient prone, the hips extended, and the knees flexed 90 degrees (Fig. 18-3). External and internal measurements of hip motion are then made, with the tibia acting as a pointer. An internal rotation deformity exists at the hip when internal rotation exceeds external rotation by more than 30 degrees.

FIG. 18-3 Measuring femoral torsion. The tibia can act as a pointer. Internal femoral torsion is present when internal rotation (A) is 30 degrees greater than external rotation. B, External femoral torsion exists when external rotation exceeds internal rotation by the same amount.

INTERNAL TIBIAL TORSION

An approximate measurement of tibial torsion can be obtained by having the patient sit on the examining table with the knees flexed 90 degrees over the side. The tibial tubercle is palpated and directed straight forward. The malleoli are then grasped with the thumb and index finger, and the position of the axis of the ankle joint is determined (Fig. 18-4). Normally, 20 to 30 degrees of external tibial torsion is present in adults, and the lateral malleolus is slightly posterior to the medial malleolus. In children with internal tibial torsion, the lateral malleolus is anterior to the medial malleolus.

FIG. 18-4 Measuring tibial torsion.

METATARSUS VARUS

With the child in the same sitting position, the foot is examined for deformity. If metatarsus varus is present, the lateral border of the foot is convex, and the medial border is concave (Fig. 18-5).

FIG. 18-5 Metatarsus varus (adductus). The lateral border of the foot is convex.

TREATMENT

Most rotational deformities in children are benign and resolve spontaneously. Treatment is by reassurance and education. There is no evidence that in-toeing causes any significant adult problems, even if mild deformity persists. Thus, treatment of femoral torsion is minimal and is first directed at simply avoiding abnormal sitting postures. The child is encouraged to sleep on the side rather than in the prone position. The reverse-tailor position should be avoided. A stool or chair, rather than the floor, should be used for sitting. Passive stretching exercise of the hips may be performed, and the family is reassured that internal rotation deformity of the hips usually corrects itself spontaneously by the age of 6 years. Roller skating is an excellent exercise for these children. The rare severe case that does not correct itself by the age of 8 years may require surgery, although some mild deformities persist into adulthood.

Tibial torsion is best treated by observation and reassurance. Spontaneous correction usually occurs with growth. Improper sitting and sleeping habits should be corrected. Stretching exercises are of no value. Corrective shoes appear to be of no benefit in the treatment of any of these problems.

The treatment of metatarsus varus depends on whether the deformity is fixed. If the foot is flexible and the deformity easily overcorrectable, passive stretching exercises and a straight or reverse-last shoe are sometimes tried, although their effectiveness is unknown (Fig. 18-6). If the forefoot is rigid and passive correction of the deformity is not possible, early treatment with corrective casts may be indicated. The correction should begin shortly after birth. When the disorder is seen after the age of 1 or 2 years, operative intervention is occasionally necessary. Early diagnosis is therefore important.

FIG. 18-6 Stretching exercises for metatarsus varus (arrows). The heel is firmly grasped. The forefoot is then passively manipulated into the corrected position and held for 10 seconds. The exercise is repeated two to three times at regular intervals during the day.

OUT-TOEING

External rotation deformity of the lower extremities is usually caused by the following: (1) external rotation of the hip secondary to soft tissue contracture or femoral retroversion (external femoral torsion), (2) external tibial torsion, or (3) pes calcaneovalgus, or flatfeet. Out-toeing is often associated with a genu valgum deformity and may be aggravated by sleeping in the prone position (Fig. 18-7). The use of wide diapers or a children’s “walker” with a wide pad may potentiate an externally rotated gait.

FIG. 18-7 The prone sleeping position, which frequently potentiates external rotation deformities.

If femoral retroversion is the cause, examination reveals that external rotation of the hips is significantly greater than internal rotation. External tibial torsion is diagnosed by the marked posterior position of the lateral malleolus compared with the medial. The flatfoot deformity is frequently associated with eversion of the heels (see Chapter 12).

GENU VARUM (BOWED LEGS)

Genu varum with mild internal tibial torsion is a common, almost normal finding in early childhood. With growth and weight bearing, this developmental bowing spontaneously corrects itself in more than 95% of patients. There is even a normal physiologic “swing” to a knock-knee deformity between the ages of 18 months and 3 years in many cases. The knock-knee deformity then usually corrects itself between the ages of 4 and 7 years.

The child is commonly brought to the doctor because of the wide space between the knees and the mild in-toeing gait. Other possible causes of bowing (such as rickets and Blount’s disease) can generally be ruled out by the child’s history. Roentgenograms may be necessary. There is usually no evidence of any intrinsic bone disease. The amount of genu varum can be determined by measuring the distance between the medial femoral condyles with the child standing and the medial malleoli touching.

Developmental genu varum is usually not severe and rarely requires any treatment. The family can be reassured that spontaneous correction usually occurs by the age of 3 years. Any associated metatarsus varus should be appropriately treated, however. Severe cases should be referred at a young age to rule out Blount’s disease.

BLOUNT’S DISEASE

This is an uncommon pathologic, developmental bowing that results from altered growth of the upper medial tibial epiphysis (Fig. 18-8). The cause is unknown, but abnormal pressure may play a role. Blount’s disease is more common in obese early walkers and children of short stature. It is also more common in blacks. It may be unilateral, in contrast to physiologic bowing, which is almost always bilateral. Two forms of Blount’s disease are described: an infantile type, which begins before age 3; and an adolescent form, which starts after age 8. Before the age of 2, the infantile form may be difficult to differentiate from physiologic bowing, especially if it is bilateral. Although physiologic bowing resolves with growth, Blount’s disease progressively worsens. A strong family history and severe bowing are indications for roentgenographic evaluation.

FIG. 18-8 Diagram of Blount’s disease, showing disturbance of the growth of the medial tibial epiphysis.

Early recognition (before age 2) and differentiation from physiologic bowing are important. Early referral is indicated for all children suspected of having the disorder. Bracing before age 3 may be effective. Otherwise, surgical correction is usually necessary.

GENU VALGUM (KNOCK-KNEE)

Knock-knee may be caused by a variety of disorders, including injury and metabolic disease. However, most genu valgum is present as one stage in the normal physiologic “swing” between developmental genu varum and normal alignment. It is usually bilateral and is most common between the ages of 2 and 4 years. The severity of the deformity can be determined by measuring between the medial malleoli or Achilles tendons with the child standing, the medial femoral condyles touching, and the patellae facing forward (Fig. 18-9). Similar measurements can be taken on return visits to confirm spontaneous correction if reassurance is needed.

FIG. 18-9 Measuring genu valgum.

Most patients need only reassurance and follow-up. The rare case that persists beyond the age of 7 years may require brace correction. If the deformity is excessive or unequal, a thorough search should be made for the underlying abnormality.

BENIGN BONE TUMORS

Most common benign bony neoplasms are either fibrous or cartilaginous. Cystic lesions such the simple bone cyst (see Chapter 5) occur with some frequency but may not be true neoplasms. The benign lesions that occur with any frequency are as follows: (1) fibrous cortical defect; (2), nonossifying fibroma; (3) fibrous dysplasia; (4) enchondroma; and (5) osteochondroma. Most of these lesions are diagnosed by a specific clinical and radiographic presentation, often related to the age of the patient and the bone involved. And although the radiographic appearance may not always be pathognomonic in all cases, certain characteristics are highly suggestive of specific lesions. Radiologic or orthopedic referral is valuable to determine the significance of such lesions.

Enchondromas are benign tumors of cartilage usually located centrally in bone. The most common sites are the small bones of the hand and feet (Fig. 18-10). The enchondroma is the most common tumor of the bones of the hand. It most often occurs in patients between the ages of 10 and 50 years. Symptoms are nonspecific. The lesion is usually discovered incidentally or is identified after a pathologic fracture. Treatment is simple observation if the diagnosis is obvious. If enough bone weakness is present, leading to recurrent fracture, or if the diagnosis is uncertain, surgical intervention is indicated.

FIG. 18-10 Enchondroma of the phalanx. The lesion is well circumscribed. A pathologic fracture is present.

Osteochondromas are the most common of all benign bone growths. They may not actually be neoplasms but are more likely developmental abnormalities thought to be the result of some “pinching-off” of a portion of growth cartilage. This lesion begins to grow separately, and its growth ceases when the patient reaches skeletal maturity. The typical site of formation is on the metaphysis near the growth plate of the distal femur or proximal tibia, but they can be found on other long bones (Fig. 18-11). Most lesions consist of a stalk that is directed away from the growth plate from which it originated. The lesion is covered with a cartilaginous cap. Signs and symptoms are related to the presence of the mass, but most are only minimally symptomatic. The lesion is removed if producing symptoms. These lesions commonly regress when growth ceases.

FIG. 18-11 Osteochondroma of the humerus. The lesion is contiguous with the normal cortex, and there is no bony destruction.

Fibrous lesions of bone are common benign neoplasms that are usually discovered incidentally. Fibrous cortical defects are common in growing bone and have a characteristic radiographic appearance (Fig. 18-12). They are asymptomatic and do not require further investigation or treatment. The lesions most likely resolve within 2 to 3 years.

FIG. 18-12 Fibrous cortical defect (arrow).

Nonossifying fibromas are similar lesions histologically but are much larger (Fig. 18-13). Biopsy is not usually required, but treatment may be needed in large lesions that are painful. These often regress as well.

FIG. 18-13 Nonossifying fibroma of the distal tibia. The lesion is well circumscribed.

Fibrous dysplasia is a developmental disturbance of bone formation in which fibroplastic proliferation occurs. The disorder may be monostotic or polyostotic. Endocrine abnormalities may also be present. Marked deformities may develop over time. The tibia is commonly involved, and pathologic fracture may occur (Fig. 18-14). Referral for surgery is indicated when deformity or pathologic fracture develops.

FIG. 18-14 Fibrous dysplasia of the tibia with bowing and a pathologic fracture.

MALIGNANT BONE TUMORS

Primary malignant bone tumors are invasive, anaplastic, and have the ability to metastasize. Most arise from the marrow (myeloma), but tumors may develop from bone, cartilage, fat, and fibrous tissues. Leukemia and lymphoma are excluded from this discussion. Fibrosarcoma and liposarcoma are extremely rare. They are similar to those tumors arising in soft tissue. Osteosarcoma is an uncommon primary malignant tumor of bone characterized by malignant tumor cells that produce osteoid or bone. Several variants have been described: parosteal sarcoma, periosteal sarcoma, multicentric, and telangiectatic forms. Chondrosarcoma is a malignant cartilage tumor that may develop primarily or secondarily from transformation of a benign osteocartilaginous exostosis or enchondroma. Ewing’s sarcoma is a malignant tumor of unknown histogenesis, and multiple myeloma is a neoplastic proliferation of plasma cells.

Multiple myeloma is the most common tumor in bone. The age of onset is usually over 40. It may present as a systemic process or, less commonly, as a “solitary” lesion. Early manifestations include anorexia, weight loss, and bone pain; the majority of cases present initially with back pain that often leads to the detection of a destructive skeletal lesion. Other organ systems eventually become involved, resulting in more bone pain, anemia, renal insufficiency, and/or bacterial infections, usually as a result of the dysproteinemia typical of this disorder. Secondary amyloidosis may develop, leading to cardiac failure or nephrotic syndrome.

Osteosarcoma most often develops between the ages of 10 to 20. Most lesions originate in the metaphysis, 50% to 60% around the knee. Pain and swelling may be present, but otherwise the patient is healthy. Osteosarcoma may develop in conjunction with Paget’s disease, manifested primarily as a sudden increase in bone pain.

Chondrosarcoma most often involves the pelvis, upper femur, and shoulder girdle in patients over age 40. Painful swelling may be the only finding.

Ewing’s sarcoma is typically a disorder that develops between the ages of 10 to 15. A painful soft tissue mass is often present sometimes with increased local heat The midshaft of a long bone is usually affected (in contrast to other tumors). Weight loss, fever, and lethargy are associated findings.

EVALUATION

The evaluation and treatment of malignant bone tumors are complicated. Diagnostic studies and treatment should be supervised by an orthopedic cancer specialist and oncologist. The age of the patient and the initial radiographic features often determine the next appropriate diagnostic steps. Laboratory evaluation may be helpful. Alkaline phosphatase is often elevated in osteosarcoma. In Ewing’s sarcoma, the findings include: reflective of systemic reaction, symptoms include anemia, an increase in white blood cell (WBC) count, and an elevated sedimentation rate. In multiple myeloma, findings include the following: (1) Bence Jones protein in the urine; (2) anemia and elevated sedimentation rate; (3) characteristic dysproteinemia on serum protein electrophoresis; (4) the diagnostic feature of a peak in the electrophoretic pattern suggestive of a monoclonal gammopathy; (5) rouleaux formation in the peripheral blood smear; and (6) often, presence of hypercalcemia, but alkaline phosphatase levels usually normal.

Imaging studies are often diagnostic. Classic osteogenic sarcoma penetrates the cortex early in many cases. The radiographic findings may vary as follows. (1) a blastic (dense), lytic (lucent), or a mixed response may be seen in the affected bone. (2) An aggressive perpendicular sunburst pattern may be present as a result of periosteal reaction, and peripheral Codman’s triangles are often noted. (3) The margins of the tumor are poorly defined.

Speckled calcifications in a destructive radiolucent lesion are usually suggestive of chondrosarcoma. Ewing’s sarcoma is characterized radiographically by mottled, irregular destructive changes with periosteal new bone formation. The latter may be multilayered, producing the typical “onion skin” appearance.

The typical roentgenographic finding in multiple myeloma is the “punched-out” lesion with sharply demarcated edges (Fig. 18-15). Other characteristics include the following: (1) multiple lesions are usual; (2) diffuse osteoporosis may be the only finding in many cases; and (3) pathologic fractures are common.

FIG. 18-15 Multiple myeloma of a vertebral body (arrows).

CERVICAL COLLARS

Cervical collars extend from the head to the thorax and are usually soft, although semirigid collars are also available (Fig. 18-17). The soft collar is usually more comfortable but restricts motion less than the other collars. These appliances are all used in the treatment of degenerative disc disease and minor ligamentous or muscular injuries of the cervical spine.

FIG. 18-17 Cervical collars. A, The soft foam collar. B, The adjustable collar. C, The Philadelphia collar.

TAYLOR BRACE

This is a fundamental back brace useful in dorsal and lumbar spine disease (Fig 18-18). It is a high, semirigid brace that may be modified. Degenerative disc disease and minor fractures may be treated with this brace or one of its modifications (long Taylor, modified Taylor, and short Taylor).

FIG. 18-18 Spinal braces. A, The Taylor brace. B, The Knight spinal (chairback) brace. C, The Jewett hyperextension brace. D, The lumbosacral support. (From Camp International, Inc, Jackson, MI. Used by permission.)

JEWETT (HYPEREXTENSION) BRACE

This three-point brace provides pressure over the lumbar spine, sternum, and symphysis pubis. It is used in minor fractures of the dorsal spine when extension is desired. It is also useful in the treatment of epiphysitis.

KNIGHT SPINAL BRACE (CHAIRBACK)

This is a rigid lumbar orthosis that is very useful in treating chronic low back pain when more support is required than a light lumbar support can provide. It is also used in the treatment of disc disease and spondylolisthesis.

LIGHT LUMBAR SUPPORTS

These supports are usually made of canvas and may be reinforced with metal stays. They are commonly used in the treatment of lumbar disc disease and chronic low back pain syndromes. They may also function to increase the intraadominal pressure, which may aid in the support of the lower portion of the back. They are more comfortable than the Knight spinal brace but provide less support.