A rare syndrome characterized by blood abnormality and recurring bone infections.
* Bone pain * Bone inflammation * Bone lesions * Bone swelling * Skin redness
Virtually any pathogenic bacteria can cause osteomyelitis under the right circumstances. Typically, these organisms find a culture site in a hematoma from recent trauma or in a weakened area, such as the site of surgery or local infection (for example, furunculosis), and spread directly to bone. As the organisms grow and form pus within the bone, tension builds within the rigid medullary cavity, forcing pus through the haversian canals. This forms a subperiosteal abscess that deprives the bone of its blood supply and may eventually cause necrosis. In turn, necrosis stimulates the periosteum to create new bone (involucrum); the old bone (sequestrum) detaches and works its way out through an abscess or the sinuses. By the time sequestrum forms, osteomyelitis is chronic. Osteomyelitis occurs more commonly in children (especially boys) than in adults — usually as a complication of an acute localized infection. The most common sites in children are the lower end of the femur and the upper end of the tibia, humerus, and radius. The most common sites in adults are the pelvis and vertebrae, generally as a result of contamination associated with surgery or trauma. Other common sites are sternoclavicular, sacroiliac, and symphysis pubis. The incidence of both chronic and acute osteomyelitis is declining, except in drug abusers. With prompt treatment, the prognosis for acute osteomyelitis is very good; for chronic osteomyelitis, which is more prevalent in adults, the prognosis is still poor.
Patient history, physical examination, and blood tests help to confirm osteomyelitis: ❑ White blood cell count shows leukocytosis. ❑ Erythrocyte sedimentation rate or C-reactive protein is usually elevated but nonspecific in acute cases. ❑ Cultures of the lesion indicate the source of the organism. Blood cultures help identify causative organism. ❑ Magnetic resonance imaging is best for detecting spinal infection. ❑ Computed tomography is best for visualizing islands of dead bone. X-rays may not show bone involvement until the disease has been active for some time, usually 2 to 3 weeks. Bone scans can detect early infection. Diagnosis must rule out poliomyelitis, rheumatic fever, myositis, and bone fractures. The gold standard for diagnosing osteomyelitis is histopathologic and microscopic examination of bone.
Treatment for acute osteomyelitis should begin before definitive diagnosis. Treatment includes administration of antibiotics after blood cultures are taken; early surgical drainage to relieve pressure buildup and sequestrum formation; immobilization of the affected bone by plaster cast, traction, or bed rest; and supportive measures, such as analgesics and I.V. fluids. If an abscess forms, treatment includes incision and drainage, followed by a culture of the drained fluid. Intracavitary instillation of antibiotics may be done through closed-system continuous irrigation with low intermittent suction; limited irrigation with blood drainage system with suction; or local application of packed, wet, antibiotic-soaked dressings. In addition to these therapies, chronic osteomyelitis usually requires surgery to remove dead bone (sequestrectomy) and to promote drainage (saucerization). The area may be filled with bone graft or packing material to promote new bone tissue. An infected prosthesis is removed and a new one is implanted the same day or after resolution of the infection. Some centers use hyperbaric oxygen to increase the activity of naturally occurring leukocytes. Free-tissue transfers and local muscle flaps are also used to fill in dead space and increase blood supply.