Three-Year Morbidity and Mortality Rates After Nontraumatic Transmetatarsal Amputation

Patients requiring a nontraumatic transmetatarsal amputation (TMA) typically have multiple comorbidities that place them at high risk of postoperative complications and additional surgery. The present study identified the demographic, clinical, and surgical risk factors that predict complications after a nontraumatic TMA, including the incidence of 3-year mortality, proximal limb amputation, and lack of healing. The electronic medical records of patients who had undergone TMA within a Kaiser Permanente Northern California facility from March 2007 to January 2012 (n = 375) were reviewed. We used bivariate and multivariate analyses to examine the variations in the rates of TMA complications according to sex, age, race, and comorbid conditions, including nonpalpable pedal pulses, end-stage renal disease, coronary artery disease, hypertension, smoking status, and preoperative albumin <3.5 mg/dL. After a nontraumatic TMA, 136 (36.3%) patients had died within 3 years, 138 (36.8%) had required a more proximal limb amputation, and 83 (22.1%) had healed without complications. The patients with nonpalpable pedal pulses had 3 times the odds of requiring a proximal limb amputation (adjusted odds ratio [aOR] 3.07; 95% confidence interval [CI] 1.84 to 5.11), almost twice the odds of dying within 3 years (aOR 1.70; 95% CI 0.98 to 2.93), and >2 times the odds of not healing after the TMA (aOR 2.45; 95% CI 1.40 to 4.31). The patients with end-stage renal disease had 3 times the odds of dying within 3 years (aOR 3.10; 95% CI 1.69 to 5.70). The present findings can help us identify patients with an increased risk of postoperative complications after nontraumatic TMA, including patients with nonpalpable pedal pulses or end-stage renal disease, and suggest the vulnerability of this patient population.