PC104. Cohort Analysis Regarding Above-Knee Amputation After Below-Knee Amputation: A Decade of Data

Abstract

It is a generally accepted long-standing clinical axiom in peripheral artery disease (PAD) patients who have had a below-knee amputation (BKA) and develop stump breakdown or infection that all efforts should be undertaken to preserve the knee joint. Conventional wisdom is that most BKA patients are ambulatory, whereas patients with an above-knee amputation (AKA) are often bedridden or wheelchair bound, with all of the negative consequences. However, it is also known that many PAD patients with BKA and multiple subsequent débridements do not ambulate, and many seem to require conversion to AKA secondary to healing issues or inadequate stump length. The purpose of this study was to examine trends in treatment with BKA, débridement, and AKA after initial BKA in PAD patients. Data of adult patients with PAD and at least one BKA between 2008 and 2018 at a single hospital system (n = 317) were examined. The first BKA during this time frame was considered the index event. Mean age for this sample was 66 ± 12 years (range, 28-90 years). Female patients made up 32% of this sample, and 91% were white. In the total sample, 28% (n = 88) had a revision (same limb) BKA or débridement, and 34% of those 88 patients required subsequent conversion to an AKA. In the total sample, 23% (n = 73) required an AKA at any time after the index event, with 90% of those revisions occurring within 1 year of the index event. Patients with an AKA after the index event had a mean age of 66 ± 13 years, 33% were female, and 91% were white. Of those with AKA after the index event, 41% received at least one follow-up BKA or débridement (revision) before proceeding to AKA. The difference in age of AKA patients with and without prior revisions was not significant (64 ± 13 years vs 66 ± 14 years; P = .538), nor was the difference in proportion of female patients (30% vs 35%; P = .801) or white patients (93% vs 89%; P = .693). The results of this cohort analysis indicate that roughly a quarter of the PAD patients with a BKA developed stump breakdown or infection requiring revision (BKA or débridement), but only a third of those patients went on to receive an AKA. BKA stump revision rather than conversion to AKA appears to be the treatment of choice in PAD patients with stump breakdown; however, a significant minority still required AKA.