Transmetatarsal Amputation: Predictors of Healing

The objective of this study is to determine the predictors of healing after transmetatarsal amputations (TMA) and factors leading to a higher level of amputation. A total of 33 TMA was performed in 31 patients during the 5 years between January 2000 and Jul 2005. All patients were men between the ages of 44 and 82 years (mean, 68 years). The mean follow-up period was 36 months (range, 1-65 months). Twelve (40%) TMA required a subsequent higher level of amputation. Seventeen (57%) TMA were successful. The average time until further proximal amputation after TMA was 3.5 months. Risk factors for subsequent higher amputation by univariate analysis included infrapopliteal arterial occlusion (P < 0.05), tobacco smoking greater than 20 years (P < 0.05), and further TMA debridement (P < 0.05). Upon multivariate analysis, only patients undergoing further TMA debridement were at risk for TMA failure (P = 0.01). The difference in ankle-to-brachial pressure ratio (ABI) between the higher amputation group (ABI = 0.51) and the successful TMA group (ABI = 0.54) was not significant. There were no perioperative deaths after TMA. Five (18%) deaths occurred at a mean of 8.2 months after the TMA. In patients who are walking preoperatively, aggressive TMA is warranted in an attempt to maintain ambulation, recognizing that requirement for further debridement, smoking history, and infrapopliteal occlusion may be predictors of nonhealing and subsequent higher amputation.