Re-amputations and mortality after below-knee, through-knee and above-knee amputations.

INTRODUCTION: From January 2013, we changed the surgical strategy in our department and ceased to perform the through-knee amputation (TKA). The primary aim of this study was to investigate re-amputation rates ≤ 90 days after non-traumatic major lower-extremity amputations performed before and after this change of practice. Furthermore, we reported mortality before and after the change of practice.

METHODS: All non-traumatic major lower-extremity amputations performed in a single centre in two study periods (before and after the change of practice); 2009-2012 (cohort A) and 2014-2015 (cohort B) were included. Re-amputations and all-cause mortality ≤ 90 days after the index amputations were analysed.

RESULTS: Cohort A: Included 180 amputations with 27 below-knee amputations (BKA), 68 TKAs and 85 above-knee amputations (AKA). 86.7% of patients were American Society of Anesthesiologists (ASA) score 3-5. The re-amputation rate ≤ 90 days was 29.6% (95% confidence interval (CI): 12.7-47.3%) after BKA, 33.8% (95% CI: 22.7-45.3%) after TKA, 9.4% (95% CI: 2.9-15.1%) after AKA and 21.6% (95% CI: 15.6-27.6%) overall. The overall mortality ≤ 90 days was 35.2% (95% CI: 26.2-44.2%). Cohort B: Included 116 amputations with 21 BKA and 95 AKA. 92.7% of patients were ASA score 3-5. The re-amputation rate ≤ 90 days was 19.1% (95% CI: 7.7-40.0%) after BKA, 2.1% (95% CI: 0.6-7.4%) after AKA and 5.2% (95% CI: 2.4-10.8%) overall. The overall mortality ≤ 90 days was 32.8% (95% CI: 26.2-44.2%).

CONCLUSIONS: The overall re-amputation rate ≤ 90 days following major lower-extremity amputation decreased significantly from 22% to 5% after cessation of the TKA procedures, but mortality remained unchanged.

FUNDING: none.

TRIAL REGISTRATION: not relevant.