Chapter 120. Osteomyelitis (Part 7)

Contiguous-Focus OsteomyelitisEven 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 OsteomyelitisThe risks and benefits of aggressive therapy for chronic osteomyelitis should be weighed before any attempt is made to eradicate the infection. Somepatients with extensive disease prefer to live with their infections rather than undergo multiple...
Nội dung trích xuất từ tài liệu:
Chapter 120. Osteomyelitis (Part 7) Chapter 120. Osteomyelitis (Part 7) Contiguous-Focus Osteomyelitis Even when diagnosed early, contiguous-focus osteomyelitis usuallyrequires surgery in addition to 4–6 weeks of appropriate antibiotic therapy becauseof underlying soft tissue infection or damage to bone from an injury or surgery. A2-week course of antibiotics after thorough debridement and soft tissue coveragehas yielded adequate results in the treatment of superficial osteomyelitis involvingonly the outer cortex of bone. Chronic Osteomyelitis The risks and benefits of aggressive therapy for chronic osteomyelitisshould be weighed before any attempt is made to eradicate the infection. Somepatients with extensive disease prefer to live with their infections rather thanundergo multiple surgical procedures, take prolonged courses of antimicrobialtherapy, and face the risk of loss of an extremity. Such persons often benefit fromintermittent courses of oral antibiotics to suppress acute exacerbations. Once the decision has been made to treat chronic osteomyelitisaggressively, the patients nutritional and metabolic status should be optimized toexpedite healing of soft tissues and bone. Antibiotic administration should bestarted several days before surgery to reduce inflammation if the etiology of theinfection is known; if not, antibiotic therapy should be withheld until debridement.A 4- to 6-week course of appropriate antibiotic therapy is given postoperatively onthe basis of the susceptibility pattern of organisms isolated from bone. Asubsequent prolonged course of oral antibiotic therapy is often prescribed,especially in the setting of a foreign body, but controlled data for this approach arelacking. There are insufficient data to recommend either the routine use ofhyperbaric oxygen or the use of antibiotic-impregnated methacrylate beads orother depots to deliver high levels of antibiotics to the bone. The success oftherapy for chronic osteomyelitis still rests largely on the complete surgicalremoval of necrotic bone and abnormal soft tissues. In the past, the inability torepair 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-tissuedefects and to fill dead space, and bone grafts and vascularized bone transfer mayrestore a seriously compromised bone to a functional state. In infections of recent fractures requiring internal fixators, such devices areoften left in place and the infection is controlled by limited debridement andsuppressive antibiotic therapy. Definitive surgical/antimicrobial therapy isdelayed until bony union of the fracture has been achieved. If there is persistentnonunion of the fracture or loosening of the fixator, the appliance must beremoved, the bone debrided, and an external fixator or a new internal fixatorapplied. Osteomyelitis of the small bones of the feet in persons with vasculardisease usually requires surgical treatment. The effectiveness of the surgery islimited by the blood supply to the site and the bodys ability to heal the wound.Revascularization of the extremity is indicated if the vascular disease involveslarge arteries. In cases of decreased perfusion due to small-vessel disease, foot-sparing surgery may fail, and the best option is often suppressive therapy oramputation. The duration of antibiotic therapy depends on the surgical procedureperformed. When the infected bone is removed entirely but residual infection ofsoft tissues remains, antibiotic therapy should be given for 2 weeks; if amputationeliminates 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 inprevious 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 Radiol12:1193, 2002 [PMID: 11976867] Khatri G et al: Effect of bone biopsy in guiding antimicrobial therapy forosteomyelitis 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: Osteomyelitis of the foot in diabetic patients. Clin Infect Dis25:1318, 1997 [PMID: 9431370] McHenry MC et al: Vertebral osteomyelitis: Long-term outcome for 253patients from 7 Cleveland-area hospitals. Clin Infect Dis 34:1342, 2002 [PMID:11981730] Rissing JP: Antimicrobial therapy for chronic osteomyelitis in adults: Roleof the quinolones. Clin Infect Dis 25:1327, 1997 [PMID: 9431371] Tice AD et al: Outcomes of osteomyelitis among patients treated withoutpatient parenteral antimicrobial therapy. Am J Med 114:723, 2003 [PMID:12829198] Tsukayama DT: Pathophysiology of posttraumatic osteomyelitis. ClinOrthop 360:22, 1999 [PMID: 10101307] Zarrouk V et al: Imaging does not predict the clinical outcome of bacterialosteomyelitis. Rheumatology 46:292, 2007 [PMID: 16877464] Bibliography Mader JT et al: Staging and staging application in osteomyelitis. Clin InfectDis 25:1303, 1997 [PMID: 9431368]