Objectives This study was undertaken to identify the relationship of objective physical performance and gait endurance after 1 month after total knee arthroplasty.
Methods One-hundred ninety-five patients (32 males and 163 females; average age 72.6±6.1 years) who underwent a primary total knee arthroplasty (TKA). Patients completed 6-minute walk test (6MWT) to assess gait endurance. Additional physical performance test including timed up and go (TUG) test, timed Stair Climbing Test (SCT), instrumental gait analysis for spatio-temporal parameters, and isometric knee flexor and extensor strength of the surgical and nonsurgical knees 1 month after TKA were measured. To evaluate self-reported physical function, self-reported disease-specific physical function measured by using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and self-reported quality of life measured by using EuroQOL five dimensions (EQ-5D) questionnaire. Visual analog scale (VAS) of post-operative knee pain was recorded each patient.
Results In the bivariate analyses, the postoperative gait endurance had a significant positive correlation with the postoperative gait speed (r=0.48, p<0.001), cadence (r=0.40, p<0.001), stride length (r=0.58, p<0.001), postoperative peak torque (PT) extensor of surgical knee (r=0.36, p<0.001), postoperative peak torque (PT) flexor of surgical knee (r=0.25, p<0.001), postoperative peak torque (PT) extensor of non-surgical knee (r=0.49, p<0.001), postoperative peak torque (PT) flexor of non-surgical knee (r=0.34, p<0.001), EQ5D (r=0.33, p<0.001) and a significant negative correlation with TUG (r=-0.46, p<0.001), SCT-ascent (r=-0.63, p<0.001), SCT-descent (r=-0.68, p<0.001), WOMAC pain score (r=-0.29, p<0.001), WOMAC stiffness score (r=-0.35, p<0.001), WOMAC function score (r=-0.43, p<0.001).
In the linear regression analyses, the postoperative Visual analog scale (VAS) (β=-6.91, p=0.03), peak torque (PT) extensor of surgical knee (β=0.56, p=0.04) and peak torque (PT) extensor of non-surgical knee (β=0.77, p<0.001) were a factors predictive of the postoperative 6MWT.
Conclusions This study demonstrated that quadriceps muscle strength significantly influenced on gait endurance 1 month after TKA. Using variables measured after surgery, it may be possible to predict with good accuracy for postoperative gait speed. In addition, these results could be of importance in determining effective rehabilitation strategies focusing on resistance training for improvement of gait speed early after TKA.
Disclosure of Interest None declared