Impact of Sarcopenia and Obesity on Gait Speed After Total Knee Replacement

Abstract

Objectives: Older adults with sarcopenic obesity have a higher risk of experiencing mobility difficulty. Additionally, sarcopenia and obesity are closely associated with knee osteoarthritis. This study investigated the associations of sarcopenia, obesity, and in combination of both with walking disability during postoperative rehabilitation in older adults with knee osteoarthritis who underwent total knee replacement.

Design: A retrospective cohort study.

Setting and participants: From a rehabilitation center database, we retrospectively selected and investigated 482 older patients with knee osteoarthritis who had undergone total knee replacement and received postoperative rehabilitation.

Methods: Sarcopenia was identified in accordance with the diagnostic criteria established by the Asian Working Group for Sarcopenia and obesity was defined as body mass index ≥ 30 kg/m². Accordingly, patients were classified into four body composition groups, namely sarcopenic obese, sarcopenic, obese, and normal (reference group). After total knee replacement, all patients attended monthly follow-up admission during the postoperative rehabilitation. Gait speed was measured before surgery and monthly after total knee replacement. A gait speed cutoff of 1.0 m/s was used to identify postoperative walking disability. Kaplan-Meier curve analysis was performed to measure the probability of experiencing postoperative walking disability among the groups. Cox multivariate regression models were established to calculate the hazard ratios of postoperative walking disability.

Results: Compared with the reference group, the sarcopenic, obese, and sarcopenic obese groups appeared to have a higher probability of experiencing postoperative walking disability (all P < .001). The sarcopenic obese group were likely to have the highest risk of experiencing postoperative walking disability (adjusted hazard ratio = 3.89).

Conclusions and implications: Sarcopenia or obesity alone may independently exert negative effects on postoperative gait speed. The participants with sarcopenic obesity were likely to have the highest risk of experiencing walking disability following total knee replacement. The findings may serve as a reference for clinicians developing rehabilitation strategies to optimize walking ability after total knee replacement, especially those preoperatively diagnosed as having sarcopenic obesity.

Keywords: Sarcopenia; mobility; obesity; osteoarthritis; total knee replacement.