# Impact of Body Mass Index on Functional Recovery After Total Hip Arthroplasty: A Prospective Study

## TL;DR

This study shows that obese patients recover more slowly after hip replacement surgery but are equally satisfied with the results as normal-weight patients one year later.

## Contribution

The study is the first to use both clinical and biomechanical assessments to evaluate BMI's impact on THA recovery.

## Key findings

- Obese patients had slower walking speed and shorter stride length at 6 months and 1 year post-surgery.
- Japanese Orthopaedic Association hip scores showed no significant differences among BMI groups at 1 year.
- Obese patients required personalized rehabilitation strategies to optimize THA outcomes.

## Abstract

The effect of body mass index (BMI) on walking recovery after total hip arthroplasty (THA) has not yet been investigated using both clinical evaluation and biomechanics. The aim of this study was to examine the effects of BMI on functional recovery at 6 months and 1 year post-THA among normal-weight, overweight, and obese individuals based on preoperative status.

This prospective case-control study involved 269 patients who underwent primary THA. Participants were categorized into normal-weight, overweight, and obese groups based on the World Health Organization criteria. Recovery outcomes were assessed across BMI groups using gait measurements and the Japanese Orthopaedic Association hip scores.

Patients with obesity exhibited slower recovery in walking speed and stride length at both 6 months and 1 year compared with normal-weight individuals and overweight patients. At 1 year postsurgery, the Japanese Orthopaedic Association hip scores showed no significant differences among the BMI groups, thereby indicating similar satisfaction levels despite initial functional recovery differences.

Although patients with obesity faced early recovery challenges, particularly regarding gait, the level of satisfaction with THA outcomes was comparable across all BMI groups at 1 year. These findings highlight the need for personalized management and rehabilitation strategies for optimizing THA outcomes in patients with obesity.