Changes in Physical Function and Locomotive Syndrome Status in the Postoperative Period Following Total Hip and Knee Arthroplasty

TL;DR

This study shows that while basic mobility remains stable after hip or knee replacement surgery, muscle strength and locomotive syndrome worsen over time, especially after 10 years.

Contribution

The study reveals time-dependent deterioration in muscle power and locomotive syndrome beyond 10 years post-surgery, even after adjusting for confounding factors.

Findings

Very long-term postoperative patients showed significantly worse 5-CS times and higher GLFS-25 scores compared to short-term patients.

Severe locomotive syndrome increased from 4.8% in short-term to 30.6% in very long-term patients.

Bilateral surgery cases increased to 61.1% in the very long-term group, likely reflecting the progression of hip dysplasia.

Abstract

Objective: This study aims to examine changes in physical function and locomotive syndrome (LS) status at different postoperative stages after total hip arthroplasty (THA) and total knee arthroplasty (TKA), emphasizing long-term functional maintenance and prevention of mobility decline.

Methods: This cross-sectional study included 118 THA or TKA patients categorized into four postoperative duration groups: short-term (<24 months, n=21), mid-term (24 to 59 months, n=29), long-term (60 to 119 months, n=32), and very long-term (≥120 months, n=36). Physical function was measured using handgrip strength, the five-chair stand (5-CS) test, one-leg standing time, usual walking speed, and a short physical performance battery. The LS status was assessed using the stand-up test, two-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25).

Results: Despite similar evaluation ages (73 to 74 years), the very long-term group had significantly longer 5-CS times (10.8±3.5 vs 8.5±2.4 seconds in short-term, p=0.04) and higher GLFS-25 scores (15.0±9.0 vs 8.5±5.7, p=0.005). Severe LS (stage 3) increased from 4.8% in the short-term to 30.6% in the very long-term group (p=0.04). In the THA subgroup analysis (n=94), these differences remained significant after adjusting for age at surgery, BMI, and bilateral surgery status (adjusted p=0.028 for 5-CS, p<0.001 for GLFS-25). Basic mobility functions such as walking speed and balance remained stable across periods. Bilateral surgery cases increased with longer postoperative duration, reaching 61.1% in the very long-term group (p=0.02).

Conclusions: Joint arthroplasty provides sustained benefits in basic mobility functions over extended periods. However, muscle power-dependent functions and LS severity show time-dependent deterioration, particularly beyond 10 years post-surgery. This decline persists after adjustment for confounders and occurs even in unilateral cases, indicating a true time-related phenomenon. The high prevalence of bilateral surgery in long-term follow-up likely reflects the natural history of hip dysplasia but does not fully explain functional decline. These findings underscore the importance of long-term monitoring and targeted interventions to maintain muscle strength, especially beyond 10 years post-surgery.

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