Bilateral Quadriceps Muscle Strength and Pain Correlate With Gait Speed and Gait Endurance Early After Unilateral Total Knee Arthroplasty: A Cross-sectional Study.

Objective: The aim of this study was to determine the correlations between objective performance-based physical function, self-reported physical function, quality of life, and gait function at 1 mo after unilateral total knee arthroplasty.

Design: Cross-sectional data from 195 patients who underwent unilateral primary total knee arthroplasty were analyzed. The isometric knee extensor and flexor strength of both knees, gait parameters, 6-min walk test, timed up-and-go test, timed stair-climbing test, knee flexion and extension range of motion of surgical knee, Western Ontario McMaster Universities Osteoarthritis Index pain, stiffness, and functional levels, EuroQol five-dimensions questionnaire, and visual analog scale for knee pain were assessed.

Results: In bivariate analyses, both postoperative gait speed and gait endurance had significant positive correlations with postoperative peak torque of the extensor and flexor of both knees, cadence, stride length, and significant negative correlation with timed up-and-go, stair-climbing test ascent, stair-climbing test descent, visual analog scale, Western Ontario McMaster Universities Osteoarthritis Index pain, stiffness, and function levels. In the linear regression analyses, postoperative peak torque of the extensors of both knees and VAS for knee pain were factors correlated with postoperative gait speed and gait endurance.

Conclusions: Quadriceps muscle strength of both knees and knee pain were important factors correlated with gait function early after total knee arthroplasty.