Chapter 120. Osteomyelitis (Part 7) ppt

Chapter 120. Osteomyelitis (Part 7) Contiguous-Focus Osteomyelitis Even when diagnosed early, contiguous-focus osteomyelitis usually requires surgery in addition to 4–6 weeks of appropriate antibiotic therapy because of underlying soft tissue infection or damage to bone from an injury or surgery. A 2-week course of antibiotics after thorough debridement and soft tissue coverage has yielded adequate results in the treatment of superficial osteomyelitis involving only the outer cortex of bone. Chronic Osteomyelitis The risks and benefits of aggressive therapy for chronic osteomyelitis should be weighed before any attempt is made to eradicate the infection. Some patients with extensive disease prefer to live with their infections rather than undergo multiple surgical procedures, take prolonged courses of antimicrobial therapy, and face the risk of loss of an extremity. Such persons often benefit from intermittent courses of oral antibiotics to suppress acute exacerbations. Once the decision has been made to treat chronic osteomyelitis aggressively, the patient's nutritional and metabolic status should be optimized to expedite healing of soft tissues and bone. Antibiotic administration should be started several days before surgery to reduce inflammation if the etiology of the infection is known; if not, antibiotic therapy should be withheld until debridement. A 4- to 6-week course of appropriate antibiotic therapy is given postoperatively on the basis of the susceptibility pattern of organisms isolated from bone. A subsequent prolonged course of oral antibiotic therapy is often prescribed, especially in the setting of a foreign body, but controlled data for this approach are lacking. There are insufficient data to recommend either the routine use of hyperbaric oxygen or the use of antibiotic-impregnated methacrylate beads or other depots to deliver high levels of antibiotics to the bone. The success of therapy for chronic osteomyelitis still rests largely on the complete surgical removal of necrotic bone and abnormal soft tissues. In the past, the inability to repair large defects in bone and soft tissue limited the extent of debridement. Muscle flaps and skin grafts are now used routinely to cover large soft-tissue defects and to fill dead space, and bone grafts and vascularized bone transfer may restore a seriously compromised bone to a functional state. In infections of recent fractures requiring internal fixators, such devices are often left in place and the infection is controlled by limited debridement and "suppressive" antibiotic therapy. Definitive surgical/antimicrobial therapy is delayed until bony union of the fracture has been achieved. If there is persistent nonunion of the fracture or loosening of the fixator, the appliance must be removed, the bone debrided, and an external fixator or a new internal fixator applied. Osteomyelitis of the small bones of the feet in persons with vascular disease usually requires surgical treatment. The effectiveness of the surgery is limited by the blood supply to the site and the body's ability to heal the wound. Revascularization of the extremity is indicated if the vascular disease involves large arteries. In cases of decreased perfusion due to small-vessel disease, foot- sparing surgery may fail, and the best option is often suppressive therapy or amputation. The duration of antibiotic therapy depends on the surgical procedure performed. When the infected bone is removed entirely but residual infection of soft tissues remains, antibiotic therapy should be given for 2 weeks; if amputation eliminates infected bone and soft tissue, standard surgical prophylaxis is given; otherwise, postoperative antibiotics must be given for 4–6 weeks. Acknowledgment The substantial contributions of Dr. James H. Maguire to this chapter in previous editions are gratefully acknowledged Further Readings Darouiche RO: Spinal epidural abscess. N Engl J Med 355:2012, 2006 [PMID: 17093252] Kaim AH et al: Imaging of chronic posttraumatic osteomyelitis. Eur Radiol 12:1193, 2002 [PMID: 11976867] Kh atri G et al: Effect of bone biopsy in guiding antimicrobial therapy for osteomyelitis complicating open wounds. Am J Med Sci 321:367, 2001 [PMID: 11417751] Lew DP, Waldvogel FA: Osteomyelitis. N Engl J Med 336:999, 1997 [PMID: 9077380] Lipsky BA: Oste omyelitis of the foot in diabetic patients. Clin Infect Dis 25:1318, 1997 [PMID: 9431370] McHenry MC et al: Vertebral osteomyelitis: Long- term outcome for 253 patients from 7 Cleveland- area hospitals. Clin Infect Dis 34:1342, 2002 [PMID: 11981730] Riss ing JP: Antimicrobial therapy for chronic osteomyelitis in adults: Role of the quinolones. Clin Infect Dis 25:1327, 1997 [PMID: 9431371] Tice AD et al: Outcomes of osteomyelitis among patients treated with outpatient parenteral antimicrobial therapy. Am J Med 114:723, 2003 [PMID: 12829198] Tsukayama DT: Pathophysiology of posttraumatic osteomyelitis. Clin Orthop 360:22, 1999 [PMID: 10101307] Zarrouk V et al: Imaging does not predict the clinical outcome of bacterial osteomyelitis. Rheumatology 46:292, 2007 [PMID: 16877464] Bibliography Mader JT et al: Staging and staging application in osteomyelitis. Clin Infect Dis 25:1303, 1997 [PMID: 9431368] . Chapter 120. Osteomyelitis (Part 7) Contiguous-Focus Osteomyelitis Even when diagnosed early, contiguous-focus osteomyelitis usually requires surgery. the treatment of superficial osteomyelitis involving only the outer cortex of bone. Chronic Osteomyelitis The risks and benefits of aggressive therapy for chronic osteomyelitis should be weighed. Imaging of chronic posttraumatic osteomyelitis. Eur Radiol 12:1193, 2002 [PMID: 11976867] Kh atri G et al: Effect of bone biopsy in guiding antimicrobial therapy for osteomyelitis complicating open