The impact of minor amputation on occurrence of major amputation in patients with diabetic foot ulcers

Diabetic foot ulcers (DFU) may lead to lower extremity amputation (LEA). Although minor LEAs (at or distal to the ankle) can carry a higher risk of perioperative complications compared to major LEAs (proximal to the ankle), they can increase patient independence and quality of life. This study aims to elucidate the impact of minor LEA on the time between DFU occurrence and major LEA to help determine the safer and more efficacious LEA choice for a given clinical situation. Data from 4,199 DFU patients from the TriNetX research platform were utilized. Kaplan-Meier curves and Cox regression were conducted to evaluate the impact of minor amputations on the likelihood of subsequent major amputations. Of the patients studied, 83 (23.85%) underwent minor LEAs, while 265 (76.15%) received major LEAs. DFU patients who had undergone a minor amputation were 28.1 times more likely (P < 0.001) in time-to-event analysis, 63.3 times more likely (P < 0.001) in time-varying analysis, with minor amputation as a time-varying covariate, and 60.8 times more likely (P < 0.001) in multivariate time-varying analysis to receive a major amputation than DFU patients who had not. DFU patients with minor LEAs were at higher risk for subsequent major LEAs. Clinically, these results imply that minor amputations are likely not the last step in a patient’s care and that their utilization should be improved. Shared decision-making with DFU patients should account for the potential for upfront major LEA to avoid complications of stepwise progression from DFU to minor to major LEA.