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therapy.

Tumors originating in cartilage

Enchondromas are frequently incidental findings on radiographs, although some present as pathologic fractures.

Epidemiology. The tumor occurs in patients aged 10–50 and is commonly found in the hand.

Clinical presentation

It is typically an intraosseous lytic lesion marked by characteristic “popcorn” calcifications and surrounded by reactive sclerosis.

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A tumor that appears radiographically to be an enchondroma must be suspected of being a sarcoma if the patient presents clinically with pain but no pathologic fracture.

Treatment. When an enchondroma causes a pathologic fracture, curettage and bone grafting are required, but such definitive treatment may be facilitated by first allowing the fracture to heal, especially in the small bones of the hand.

Osteochondromas are benign, easily palpable tumors of bone. They are quite common.

Clinical presentation

They grow during adolescence, as does any cartilage portion of bone. If pain or growth occurs after skeletal maturity, malignant degeneration must be suspected and excisional biopsy is warranted.

Osteochondromas may be symptomatic because of their prominence due to overlying tendon irritation or neurovascular compression.

Treatment. If symptoms warrant, osteochondromas can be excised, including the soft tissue covering and cartilage. Bone grafting is generally not necessary.

Chondroblastomas are less common cartilage tumors that almost always occur within the epiphysis of long bones.

Epidemiology. More than 70% of these tumors occur during the second decade of life. They are rare if the growth plates have closed.

Clinical presentation. They are benign lesions, but a few undergo malignant degeneration.

Treatment. They frequently require excision and bone grafting.

Chondromyxoid fibromas are relatively rare tumors.

Epidemiology. They usually occur in the first and second decades of life.

Clinical presentation. The tumor is a relatively large, well-defined lytic lesion with a sclerotic rim and is found in the metaphysis juxtaposed to the growth plate. It may present with pathologic fracture.

Treatment. Curettage and bone grafting may be required for treatment.

Chondrosarcoma is a primary malignant tumor that occurs in adulthood and sometimes develops in pre -existing benign cartilage lesions.

Epidemiology. It occurs with an essentially constant incidence in patients from 10–70 years of age.

Clinical presentation

Typically, the tumor presents with pain and tumefaction.

Radiographs may show a lytic lesion with or without stippled calcification. Cortical thickening and scalloping of the adjacent endosteal bone are frequently seen.

The tumor is locally recurrent.

Treatment is surgical, and the goal is to obtain a 2-cm margin of tumorfree tissue.

Other primary tumors

Giant cell tumors occur in the epiphyseal–metaphyseal region of long bones, especially about the knee in the femur and tibia and in the distal radius. The lesions are benign but are problematic because of their propensity to recur locally.

Epidemiology. Giant cell tumors occur in young adults and particularly in patients between the ages of 20 and 30. The patient is almost always skeletally mature.

Clinical presentation. The lesion usually extends to the subchondral plate of the joint. It is a lytic lesion and is fairly well circumscribed with some ballooning of the cortex.

Histology. The lesion is characterized histologically by the giant cells found in a benign stroma. The giant cell nuclei and the stroma nuclei are identical in appearance.

Treatment. Curettage is often accompanied by cryotherapy, phenol chemocautery, or electrocautery of the residual cavity. The lesion may be packed with methylmethacrylate bone cement, or bone grafting may be done. A recurrence usually requires wide resection of the involved bone.

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Unicameral bone cysts are lytic expansile lesions of bone that occur in older children in the metaphyseal region that extends to the growth plate. The proximal end of the humerus is the most common site.

Clinical presentation. Typically, the patient presents with a pathologic fracture, and ultimately, the cyst may resolve in response to this trauma.

Treatment. Unicameral bone cysts may be managed with intralesional steroid injections

administered under radiographic control. Multiple injections may be required, which present a problem in growing children.

Ewing's sarcoma is a disease of childhood and adolescence. It occurs evenly among individuals younger than 20 years of age.

Clinical presentation

Typically, the patient presents with significant tumefaction and pain in the involved area.

The history, physical examination, and radiographic findings mimic those of osteomyelitis.

Radiologically, the lesion is seen to be a lytic bone lesion characteristically involving the diaphysis with some periosteal reaction.

Histology. Histologically, this is a tumor of small round cells, which may form pseudorosettes reminiscent of neuroblastoma. Chromosomal translocation t11:22 is associated with Ewing's sarcoma.

Treatment. The relative roles of chemotherapy, radiation therapy, and surgical therapy are being evaluated.

These tumors are sensitive to both chemotherapy and radiotherapy, and together these modalities have a significant cure rate.

However, new information suggests that patients are at risk of forming osteosarcoma in the radiated bone during early adulthood.

Fibrosarcoma is a tumor that occurs in adulthood, between 20 and 70 years of age.

Clinical presentation

It is predominantly a lytic lesion that occurs in the femur and tibia about the knee.

It presents with pain and a radiographic appearance of a purely lytic lesion of bone.

Histology. Histologic examination shows sheets of spindle cells in a herringbone pattern and with various amounts of atypism.

Treatment involves wide surgical excision.

Multiple myeloma

Epidemiology. Whether this lesion is a primary tumor of bone or bone marrow is a matter of debate. Regardless of its classification, it is a common tumor that occurs in patients who are 30 years and older with a peak incidence at 50–60 years of age.

Clinical presentation

Multiple myeloma is characterized by overproduction of monoclonal

immunoglobulins or immunoglobulin subchains (Bence Jones protein).

The initial presentation is often a pathologic fracture, frequently of the spine or long bones.

The diagnosis should be suspected when lytic lesions are found in a patient with anemia, an elevated sedimentation rate, and elevated serum calcium levels.

Diagnosis

The diagnosis can be made by serum or urine electrophoresis or immunophoresis in 95% of cases, but 5% of patients with myeloma are nonsecretors of M protein (immunoglobulins or Bence Jones protein).

Biopsy of the bone marrow to identify secreting and nonsecreting tumors shows plasma cells replacing the marrow. The percentage of bone marrow replacement offers some prognostic information.

Plain radiography reveals punched -out lytic lesions, with little adjacent reactive bone, that occur frequently in the spine, pelvis, proximal femur, and skull.

Bone scans are typically “cold” in the absence of pathologic fracture.

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Treatment is by a combination of chemotherapy and radiation therapy with palliative surgical fixation of pathologic fractures to improve the patient's quality of life.

B Metastatic disease

Tumors metastatic to the skeleton are more common than primary musculoskeletal tumors. Primary tumors that metastasize to bone include carcinomas of the breast, lung, prostate, thyroid, and kidney, or indeed, almost any type of tumor.

Diagnosis

Most bony metastatic disease presents with pain in the involved bone. Metastatic bone disease may be the initial presentation of a malignancy.

Radiographs show most bone lesions to be lytic. With some breast tumors and most prostatic tumors, the bone lesion has a blastic appearance.

Bone scans are helpful when a single symptomatic lytic lesion is found on initial radiographs.

If the bone scan shows multiple lesions, the likelihood of metastatic disease is high.

Bone scanning may also demonstrate a lesion that is likely to cause a fracture.

Skeletal metastases of unknown origin are best worked up with a history and physical examination; whole -body bone scan; plain radiographs of the chest and the involved bone; and a CT scan of the chest, abdomen, and pelvis.

Treatment

The treatment for most metastatic lesions in bone is radiation therapy. If the pain does not respond

to irradiation, a pathologic fracture has probably occurred (or is about to occur) and should be surgically fixed. Pathologic fractures generally should be fixed internally, using a combination of metal implants plus methylmethacrylate bone cement to manage bone loss.

Impending pathologic fractures (see II A 3 e)

V Arthritis

A Classification

Degenerative joint disease

Primary osteoarthritis is typically seen with Heberden's nodes and asymmetric hip, knee, and spine involvement. The site of primary pathology is the articular cartilage.

Post -traumatic arthritis of an isolated joint can occur following trauma to that joint.

Rheumatoid arthritis and its variants include the autoimmune group of inflammatory diseases in which the hyaline articular cartilage is secondarily attacked by a local invasive pannus that primarily involves the synovium.

Crystal deposition diseases include gout and calcium pyrophosphate deposition disease. These diseases usually present as an isolated hot, inflamed joint.

Infectious arthritis (see III A 2) also presents as an isolated hot, inflamed joint.

This is the one form of arthritis that requires immediate emergency care.

The diagnosis can be made by aspirating the joint fluid and examining it microscopically for cells, organisms, and crystals as well as by cell count and culture.

B Nonoperative management

Pharmacologic management is maximized by consultation with a rheumatologist.

Nonsteroidal anti -inflammatory drugs (NSAID)

NSAIDs are especially important in rheumatoid arthritis, which requires a long-term maintenance regimen.

The crystalline and degenerative joint diseases require NSAIDs during acute flare -ups, but the natural history of these diseases is not altered by long-term management with these drugs.

Corticosteroids

These can be used in rheumatoid arthritis when NSAIDs fail to quiet the inflammation.

They can be used systemically if multiple joint involvement or generalized disease is the problem.

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They can be used locally by instillation into a single joint in patients with degenerative or post-traumatic rheumatoid arthritis.

Immunosuppressants or cytotoxic agents such as methotrexate are being used more frequently to avoid detrimental side effects of chronic steroid use and as a disease -modifying agent.

Gold and remittive agents are indicated when the patient has not been successful with NSAIDs but are often poorly tolerated.

Anti -TNF (tumor necrosis factor) alpha agents are a recent addition to the armamentarium in treating rheumatoid disease and have shown great promise as disease -modifying agents.

Exercise and splinting have an important place in the treatment of all forms of arthritis after the acute joint inflammation has been controlled. The exercise is designed to maintain a full range of joint motion as well as to maintain muscle strength by exercising the joint through a limited, painless arc of motion. Splinting in a functional position prevents establishment of contractures.

C Operative management

Types of surgical procedures

Osteotomy

If the bone is cut and the joint is realigned, this may alter the mechanics enough to give significant, although incomplete, relief from pain.

In order for the osteotomy procedure to be successful, the disease process must not have completely destroyed the joint but must leave some remaining articular surface.

Osteotomy is designed to transfer weight bearing onto this relatively normal articular surface in the setting of noninflammatory arthritis.

Osteotomy about the hip and knee can be performed as a temporizing measure in patients too young to consider arthroplasty but who wish to preserve motion.

Arthrodesis

In this procedure, the joint surfaces are excised and the extremity is immobilized so that the joint heals in a fixed position.

Arthrodesis is indicated for the relief of pain, especially in young individuals.

The results of arthrodesis are very durable and long lasting.

Any patient who is young or has a high functional demand should be considered for arthrodesis rather than for arthroplasty.

Arthrodesis is commonly used in the small joints of the wrist, hand, foot, and ankle in all age groups.

Arthroplasty , or total joint replacement, relieves pain, preserves motion and is the most common surgical treatment for arthritis.

It can be used for joints destroyed by any of the arthritides; however, postinfectious arthritis is a relative contraindication to arthroplasty because of the increased risk of infection around the implant.

Arthroplasty is indicated for the relief of pain predominantly in patients who are usually older and less active.

At the present state of the art, the typical “life expectancy” for a hip or knee arthroplasty implant is about 15 years, depending on the functional requirements and weight of the patient. Failure is at a rate of roughly 1% per year.

Major joints such as the hip, knee, shoulder, and elbow are common sites for arthroplasty.

VI Pediatric Orthopedics

A

Developmental dislocation of the hip (DDH) is most common in female neonates, especially if the child is firstborn and was in the breech presentation. The condition is bilateral in 10% of patients.

Diagnosis can be made within the first 2 weeks after birth, once relaxin is gone from the child's circulation.

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Physical examination

The examiner can feel a click on reduction of the dislocated hip (Ortolani's sign).

The examiner is able to dislocate the hip with the thigh flexed to 90 degrees (Barlow's test).

Other physical findings (especially if the dislocation is unilateral) include asymmetry of the gluteal fold and asymmetric leg lengths, which are demonstrated by the height of the thigh when the hips are flexed to 90 degrees.

Radiographs confirm the diagnosis.

Treatment. A hip that can still be dislocated after 2 weeks of age should be treated.

The initial management is with a Pavlik harness.

Double and triple diapering probably has no significant effect on the dislocation.

Persistent dislocation of the hip after the commencement of ambulation typically requires surgical treatment.

B Legg-Calvé-Perthes disease

Etiology

Idiopathic osteonecrosis of the proximal femoral epiphysis can cause this disease.

This disease typically occurs in children 4–10 years old who are small for their age.

Males are affected more than females (5:1).

Clotting abnormalities and endocrinopathy (hypothyroidism) have been associated with Perthes disease.

Diagnosis

Patients often complain of knee pain, which is “referred” from the hip. In a child, this complaint should prompt an evaluation of the hip.

Hip irritation and limitation of internal rotation and abduction are common.

Radiographs of the hip demonstrate variable degrees of collapse of the femoral epiphysis.

Treatment

Restoration of range of motion and containment of the femoral head within the acetabulum are the cornerstones of treatment.

Traction followed by splinting in the abducted and internally rotated position may be tried.

Surgery may be necessary to redirect the femoral head into the acetabulum to allow it to reossify in a shape that matches the acetabulum and is as spherical as possible.

The single factor that is most predictive of a good outcome is the age at presentation (infants < 6 years old tend to do well regardless of treatment).

C Slipped capital femoral epiphysis (SCFE)

Etiology

SCFE was thought initially to be idiopathic; however, new evidence may point to a subtle endocrinopathy.

Hypothyroidism should be suspected in children who develop SCFE before the age of 10–12 years.

There is a high incidence in children with renal failure and also in African -American males and obese children.

Diagnosis

A patient who is 10–13 years of age with hip or knee pain should be suspected of having SCFE.

Anteroposterior and frog lateral radiographs of the hip should be obtained in all patients who are suspected of having SCFE.

SCFE is bilateral in 20%–40% of patients without endocrinopathy and in 50% with endocrinopathy.

Treatment. Stabilization in situ with a single screw placed into the center of the femoral capital epiphysis is the preferred treatment.

DScoliosis

Etiology

The most common form of scoliosis in the United States is the idiopathic scoliosis that occurs most commonly in adolescent females, beginning approximately at 11 or 12 years of age and progressing until growth is completed.

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Scoliosis can also be the result of neuromuscular paralysis, painful lesions, radiation, thoracic surgery, and congenital anomalies.

Clinical presentation

Idiopathic scoliosis occurs most commonly as a right thoracic curve, but thoracolumbar, lumbar, and double major curves can occur.

Thoracic curves are most noticeable because of the associated chest rotation and deformity, which create a rib hump.

If the scoliosis is severe, exceeding about 90 degrees, significant cardiopulmonary complications can occur as a result of compromise of the chest cavity.

Treatment

Braces. The Milwaukee and Boston braces are traditionally the initial form of treatment for scoliosis. They may eliminate the need for surgery in many patients.

The brace is not expected to correct a curve that is already established when the diagnosis is made but is meant to prevent progression of the scoliosis.

A brace is used if the curve measures about 20 degrees in a patient with significant growth still remaining.

The patient is placed in a brace if the scoliosis, even with a smaller angle, is clearly progressing during a period of observation.

Surgery

Various surgical techniques are available, but the one that is most commonly performed is bone graft fusion of the spine over the area of the curve, facilitated by rod fixation using a segmental system with screws into the pedicles of the vertebrae.

Significant (although never complete) correction is obtained, and the long-term results are maintained by fusion of the spine in the corrected position.

E

Foot deformities constitute a large part of pediatric orthopedic practice.

Etiology

Idiopathic foot deformities are quite common and include metatarsus adductus, talipes equinovalgus (clubfoot) , and planovalgus.

A careful neurologic evaluation must be done to make sure that the foot deformity is not due to a neuromuscular disorder. Poliomyelitis, cerebral palsy, myelomeningocele, diastematomyelia, and Charcot -Marie -Tooth muscular atrophy can all present with foot deformities.

Developmental dislocation of the hips must be ruled out whenever a child presents with a foot deformity.

Flatfoot seldom presents a significant problem and does not need treatment unless it causes symptoms or unless the neurologic examination is abnormal.

Clubfoot requires early treatment.

Repeated manipulation and casting will correct the deformity in many cases.

However, if the foot is relatively resistant to manipulation and casting, surgery may be indicated.

In recent years, surgical soft tissue releases before 1 year of age have shown a better prognosis than manipulation and casting.

Recurrence of the clubfoot despite correction remains a problem until the cartilaginous anlage of the child's foot has become the fixed osseous bone of the adolescent.

Neuromuscular foot disorders

Treatment of the “neuromuscular foot” includes initial correction to a plantigrade neutral foot, either by manipulation of the very immature foot or by osteotomy and fusion of the more mature adolescent foot.

Once the foot alignment is corrected, muscle transfers are carried out to prevent recurrent deformity. Tendons are transferred to replace the function of a paralyzed foot or to weaken the function of a spastic foot.