Present-day analysis of early failure after forefoot amputation.

BACKGROUND: Forefoot transmetatarsal amputation is performed commonly to achieve limb salvage, but transmetatarsal amputations have a high rate of failure, requiring more proximal amputations. Few contemporary studies have examined the incidence of major amputation (transtibial or transfemoral) after transmetatarsal amputation. The goal of this study is to determine risk factors and outcomes for a more proximal amputation after forefoot amputation.

METHODS: We queried the 2012 to 2016 database of the American College of Surgeons National Quality Improvement Program for patients undergoing a complete transmetatarsal amputation with wound closure by Current Procedural Terminology code. Patients requiring early (within 30 days) more proximal amputation after transmetatarsal amputation were compared with those who did not need further amputation. Characteristics of patients requiring more proximal amputation were examined, and a multivariable logistic regression model was created to identity risk factors for early more proximal amputation.

RESULTS: In the study, 1,582 transmetatarsal amputation were identified. Most patients were male (70%), white (59%), and diabetic (74%), with a median age of 63 years. More proximal amputation occurred in 4.2% of patients within the first 30 days postoperatively. This early failure was associated with greater hospital stays postoperatively (10 days vs 7 days), more wound complications (29% vs 11%), pneumonia (8% vs 2%), stroke (3% vs 0.1%), and overall complications (50% vs 28%; P ≤ .025 each). Although there was no difference in 30-day mortality (P = .27), there was a marked increase in unplanned readmission (59% vs 14%; P < .0001) for those undergoing reamputation. On multivariable analysis, preoperative systemic inflammatory response, sepsis, or septic shock (odds ratio 2.1; 95% confidence interval, 1.2-3.6) were independent predictors of more proximal amputation.

CONCLUSION: Early below-knee or above-knee amputation early after transmetatarsal amputation leads to increased morbidity. Because patients with preoperative sepsis may be at increased risk of failure after transmetatarsal amputation, the level of amputation should be considered carefully in these patients.