Preoperative predictors of locomotor ability two months after total knee arthroplasty for severe osteoarthritis

Objective. To identify preoperative predictors of locomotor ability 2 months after total knee arthroplasty (TKA). Methods, Sixty-five participants scheduled for a first TKA were recruited. The dependent variable was the distance covered during the 6-minute gait test 2 months after TKA. The independent variables, measured before surgery, were grouped into 3 categories: 1) personal; 2) organic system, and 3) capability variables. Multiple regression analyses were conducted to determine the best predictors of the dependent variable. Modified cross-validation of the model combining predictors from the three categories was obtained with 10 random samples derived from the original cohort by resampling with replacement. Results. Predictors were identified in the 3 categories: 1) gender, number of comorbidities, body mass index, 2) knee pain, flexion and strength, lower limb mechanical power, and 3) preoperative 6-minute gait distance. When these variables were modeled to-ether only the preoperative 6-minute gait distance and knee pain and flexion remained significant (adjusted R-2 = 0.66). Conclusion. Using variables easily measured before surgery, it is possible to predict with good accuracy locomotor ability 2 months after TKA.