Session IV Scientific Basis for Fracture Care

Osteomyelitis: Treatment with Aggressive Debridement and Short Term Antibiotics

John R. Schwappach, MD, Marc F. Swiontkowski, MD, Douglas P. Hanel, MD, Nicholas B. Vedder, MD

Harborview Medical Center, Seattle, WA

Purpose: Most osteomyelitis protocols emphasize long term intravenous antibiotics. The purpose of this study is to measure the success of treatment of chronic osteomyelitis with single stage aggressive debridement and appropriate soft tissue coverage coupled with short term (5-7 days) intravenous antibiotics. Our hypothesis is that no difference exists in treatment outcomes of union, drainage and function between seven days and six weeks of intravenous antibiotics.

Conclusion: Compared to a series of historical controls treated by the senior author with 6 weeks of intravenous antibiotics no difference in outcome is noted.

Methods: Patients with chronic osteomyelitis underwent single-stage, aggressive debridement and appropriate soft tissue coverage. In the current study group (N= 95), culture-specific intravenous antibiotics were used for 7 days, followed by 6 weeks of oral therapy. A historical control group of patients (N = 22) were treated with 6 weeks of intravenous antibiotics followed by 6-12 months of oral therapy. During surgery, the scar was excised en bloc, including the sinus tract. A high-speed, saline-cooled burr was used to remove necrotic bone. Osseous laser Doppler flowmetry was used to ensure that the remaining bone was viable. Dead space management consisted of antibiotic-impregnated polymethylmethacrylate beads, which were exchanged for an autogenous bone graft at 6 weeks. Soft tissue coverage was often facilitated by free tissue transfer.

Results: Outcomes were based on fracture union, wound drainage and function. The average age of the current study patients (72 men, 23 women) was 45 years (18-77 years). Infection was classified according to Cierny as Type I (16), Type II (22), Type III (30) and Type IV (27). Prior to referral, patients averaged 27 months of drainage and 5 surgical debridements. Common infecting organisms were S. aureus (54), Pseudomonas (12) and mixed aerobic and anaerobic infections (15). Defects required antibiotic impregnated cement beads 39 times. Soft tissue coverage was necessary in 56 patients with 33 free tissue transfers. The mean follow-up was 18 months. Five patients have subsequently died; two were peri-operative deaths. One patient required acute amputation for squamous cell carcinoma. Of the remaining 89 patients studied, 81 healed without further operations. Persistent wound drainage was present in 7 patients two of which required subsequent amputation. Patients ambulating free of assist devices numbered 78 with four using either a cane or walker. The control group was different in Cierny classification, the use of antibiotic beads and in the infecting organisms. There was no difference in union or persistent wound drainage.

Discussion: Cost effective treatment of osteomyelitis is a challenging endeavor. Our protocol of aggressive debridement and appropriate soft tissue coverage coupled with seven days of intravenous antibiotics was effective with 91% fracture union, 92% dry wounds, and 88% patients ambulating without assist devices. The magnitude of the surgery can be underscored by our two peri-operative deaths. Two patients still required late amputations. Despite this, the cost savings from only seven days of intravenous antibiotics warrant further study.