Functional Status and Adverse Outcomes in Ambulatory Patients Undergoing Above-Knee Versus Below-Knee Amputation in the Vascular Quality Initiative

Previous studies in the literature have demonstrated higher morbidity and mortality patients undergoing above-knee (AKA) vs below-knee (BKA) amputations. However, very few looked at functional status between these two groups. Using a large national database, we hypothesize that BKA will be more likely to ambulate superior outcomes compared with AKA. All ambulatory major lower extremity amputations (AKA BKA) from 2013 2020 using Vascular Quality Initiative database were included. Standard univariate (Student’s t-test, χ2) multivariable (logistic regression) analyses used evaluate primary (30-day discharge) secondary (any complications, cardiopulmonary, renal failure, return operating room) outcomes. Cox regression analysis was nonambulation during long-term follow-up. A total of 9718 identified (64%) or AKA (36%). Patient on average 5-years older (mean age ± standard deviation: 67.1 12.3 62.6 12.5), female (40% 20%), had prevalence smoking (74% 65%), coronary artery disease (34% 30%), pulmonary (chronic obstructive disease) (26% prior history bypass (37% 21%) (all P < .05). In contrast, obese 27%), diabetics (75% 56%), dialysis (20% 14%), (45% 30%) logistic analysis, BKA, associated significant odds developing any complications (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.62-0.83) room (OR, 0.42; CI, 0.34-0.53) (both .001) (Table I). 47% increased discharge 1.47; 1.33-1.64) 80% 30-day 1.80; 1.47-2.23) mean follow-up 1.05 (standard deviation, 0.41) years, remained 43% hazard risk (hazard ratio, 1.43; 1.28-1.6; II). Other predictors 50-80, >80, black race, gender, smokers, chronic disease, dialysis, emergent/urgent presentation .05) risk-adjusted data demonstrate significantly BKA. addition index amputation level, patient comorbidities physiological are strong determinants follow-up.Table IMultivariable short-term amputationsOR95% CIP valueNonambulatory discharge1.471.33-1.64<.00130-day mortality1.81.47-2.23<.001Any complications0.720.62-0.83<.001Cardiac complications0.990.80-1.23.93Pulmonary complications1.080.83-1.40.58Renal failure0.990.77-1.27.94Any room0.420.34-0.53<.001CI, Confidence interval; OR, ratio.Adjusted for age, insurance type, transfer status, obesity, smoking, diabetes, anemia, American Society Anesthesiologists class 4-5, preop anticoagulation, ipsilateral procedures (amputation, bypass), surgical indication, urgency, anesthesia, staged procedure, estimated blood loss. Open table new tab Table IIMultivariable follow-upHR95% valueAbove knee amputation1.431.28-1.60<.001Age <501 (Ref) 50-801.281.07-1.52.006 >801.781.41-2.24<.001Female1.241.11-1.38<.001Black race1.271.13-1.42<.001Smoker1.141.01-1.29.04COPD1.151.01-1.31.04Dialysis1.511.30-1.74<.001Emergent/urgent1.141.02-1.28.02CI, COPD, disease; HR, smoker, hypertension, heart (COPD), amputation, urgency (elective emergent/urgent).