Lower Extremity Amputation in the Unhoused Population

Unhoused patients are a group at high risk for lower extremity amputation because of higher rates of cardiovascular disease prevalence, higher rates of foot infection treatment failure, and poorer diabetes control. The aim of this study is to identify any disparities in preoperative optimization or postoperative outcomes following lower extremity amputation between housed and unhoused patients, with the intention of modifying patient management and enhancing long-term outcomes in this high-risk population.

This is a single institution, retrospective analysis of 1,304 patients who underwent major lower extremity amputation (above-knee amputation, through-knee amputation, and below-knee amputation) between 2007-2021. Generalized estimating equations were fit to assess differences between housed and unhoused populations. Multivariable models were fit assuming binomial distribution, Poisson distribution, or cumulative logistic regression.

Unhoused patients received amputations at a younger age (P < 0.001) and had higher rates of current smokers (P = 0.001). Unhoused patients were less likely to be on an antiplatelet (P = 0.002) or statin (P = 0.005) and were less likely to have received an angiogram before their amputation (P < 0.001). Unhoused patients were more likely to have a surgical site infection postoperatively (P = 0.046). Multivariable analysis indicated a significant difference in the time to ambulation (P < 0.001), with the unhoused cohort associated with an incidence rate ratio of 0.16 (95% confidence interval: 0.07-0.36), adjusting for race, smoking status, and venous thromboembolism.

The unhoused cohort received amputations at a younger age compared to their housed counterparts. The unhoused were less likely to be on an antiplatelet or statin medication and less likely to have had an angiogram before their amputation. The unhoused were more likely to experience a surgical site infection and a longer nonambulatory period following their amputation. Street medicine clinics are an effective option for optimizing medical management preoperatively and providing postoperative follow-up for unhoused patients who are unlikely to return to outpatient clinics for medical care.