Predictors of outcome of forefoot surgery for ulceration and gangrene

BACKGROUND: Surprisingly little is known about the long-term outcome of forefoot surgery for limb salvage. METHODS: From January 1, 1992 through December 31, 1996, patients requiring toe amputation or forefoot surgery were prospectively entered into a computerized database and followed up for healing, need for repeat foot surgery, or major amputation (below or above knee). RESULTS: A total of 162 patients (mean age 65 years), 72% diabetic, 10% with end-stage renal disease (ESRD), and 73% without palpable pulses, were entered into the study. Mean follow-up was 25 months. Of patients without palpable pulses (n = 98), 83% underwent concomitant or subsequent limb revascularization. Eleven of 98 revascularization procedures (11%) were hemodynamically unsuccessful. Nonhealing of the initial forefoot procedure occurred in 14%, and late repeat foot surgery (following initial healing) was required in an additional 14%. Major amputation was eventually required in 30 (18.5%) patients. Multivariate analysis indicated that unsuccessful revascularization, but not diabetes or ESRD, predicted nonhealing and major amputation (P <0.0001). Patients presenting with palpable pulses and neuropathic ulcers were at risk for late, repeat foot surgery, but not major amputation (P = 0.0015). CONCLUSIONS: In patients requiring toe or partial forefoot amputation, success of revascularization is the primary predictor of initial healing and freedom from major amputation. Neuropathic ulceration predicts need for repeat foot surgery following healing.