The Effect of Body Mass Index and Hip Abductor Brace Use on Inpatient Rehabilitation Outcomes After Total Hip Arthroplasty

Objective: To determine the effect of body mass index and hip abductor brace use on inpatient rehabilitation outcomes after total hip replacement. Design: This was a retrospective, comparative study of natural course of rehabilitation care in 15 inpatient rehabilitation facilities. Patients with total hip replacement (n = 1947) and inpatient rehabilitation were stratified into four body mass index groups: nonobese (body mass index <25 kg/m(2)), overweight (25-29.9 kg/m(2)), moderately obese (30-40 kg/m(2)), severely obese (body mass index >= 40 kg/m(2)), and further stratified by hip abductor brace (brace, no brace). The proportions of patients in each group who used hip abductor braces ranged from 14.5%-17.5%. The main outcomes were length of stay, functional independence measure scores, facility-related charges, and discharge destination. Results: Length of stay was 0.8-1.3 days longer in the body mass index <25 kg/m(2) group compared with the remaining body mass index groups (P < 0.05). Average, improvement in total and motor functional independence measure scores ranged 53%-58% and 74%-83% across groups (both P < 0.001). Total rehabilitation charges were highest in the <25 kg/m(2) body mass index group ($ 15,125 vs. $ 13,608-14,622; P < 0.0001). Hip brace use was associated with an average of $697 excess therapy/pharmacy charges during the rehabilitation stay, but no differences in other outcomes. Conclusions: Severe obesity and abductor brace use do not impair rehabilitation functional gains or discharge home, but is related with excess rehabilitation costs. Hip abduction braces do not seem necessary during rehabilitation, particularly for obese patients.