Background Knee osteoarthritis (OA) is among the most common joint disease and is therefore a major social and health problem. Clinically, the knee OA is characterized by joint pain, tenderness, limitation of movement, and variable degrees of local inflammation.
Objectives This study was undertaken to identify preoperative physical performance factors predictive of self-reported physical function and quality of life, and to propose a preoperative rehabilitation program to improve functional ability in patients scheduled for total knee arthroplasty.
Methods A total of 55 older adults with end-stage knee OA awaiting a total knee arthroplasty (6 males and 49 females; average age 73.3±6.1 years) were recruited and tested preoperatively. Self-reported disease-specific physical function and self-reported pain were measured by using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC). Self-reported quality of life was measured by using EuroQOL five dimensions (EQ-5D) questionnaire. Physical performance tests included 6-minute walk test (6MWT), timed up and go (TUG) test, instrumental gait analysis for spatio-temporal parameters, and isometric knee flexor and extensor strength of the surgical and nonsurgical knees.
Results In the bivariate analyses, the WOMAC function score had a significant positive correlation with the WOMAC pain score (r=0.62, p<0.001), TUG (r=0.46, p<0.001) tests, and a significant negative correlation with 6MWT (r=-0.46, p<0.001), peak torque (PT) extensor (r=-0.27, p=0.04) and PT flexor (r=-0.32, p=0.02) of the nonsurgical knee. The EQ-5D score had a significant positive correlation with 6MWT (r=0.46, p<0.001) tests, and a significant negative correlation with the WOMAC pain score (r=-0.60, p<0.001), TUG (r=-0.38, p=0.004). In the linear regression analyses after adjustment for demographics and anthropometrics variables, the WOMAC pain score (β=0.55, p<0.001) and preoperative TUG test (β=0.34, p=0.002) were factors predictive of the WOMAC function score (R2=0.49), and the WOMAC pain score (β=-0.51, p<0.001) and preoperative 6MWT test (β=0.30, p=0.008) were factors predictive of the EQ-5D score (R2=0.45).
Conclusions This study demonstrated that preoperative physical performance significantly influenced on self-reported physical function and quality of life in patients scheduled for total knee arthroplasty. Because functional ability after total knee arthroplasty is strongly associated with preoperative functional ability, these results could be of importance in determining variable preoperative rehabilitation strategies, especially focusing on resistance, dynamic balance, and endurance exercises.
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Disclosure of Interest None declared