Japanese Knee Osteoarthritis Measure at Two Weeks as a Key Predictor of Early Functional Recovery After Total Knee Arthroplasty.

Abstract

Early postoperative functional recovery is a major determinant of patient satisfaction following total knee arthroplasty. Although patient-reported outcome measures are increasingly used, the prognostic value of early postoperative assessments remains incompletely understood. This retrospective observational study included 180 patients who underwent primary total knee arthroplasty at our institution. The Japanese Knee Osteoarthritis Measure (JKOM), pain intensity, mobility tests, muscle strength, and balance performance were evaluated preoperatively and at two and four weeks postoperatively. Patients were stratified into early and delayed recovery groups based on the median four-week JKOM score. Group comparisons and correlation analyses were performed to identify early predictors of recovery at four weeks after surgery. Patients in the delayed recovery group demonstrated worse JKOM scores, higher pain levels, and poorer functional performance at two weeks postoperatively. The JKOM score at two weeks showed a strong association with the score at four weeks (r = 1.00), likely reflecting the close temporal proximity and repeated assessment using the same PROM instrument. Resting pain and walking pain were associated with delayed recovery. In addition, objective functional measures, including gait performance, balance ability, and knee muscle strength, showed moderate correlations with patient-reported outcomes. Patient-reported outcomes assessed at two weeks after total knee arthroplasty, particularly JKOM scores, provide useful prognostic information on recovery at four weeks. Pain severity and early functional impairment are closely associated with delayed recovery. Integrating early patient-reported outcome assessments with objective functional evaluations may facilitate early risk stratification and support individualized postoperative rehabilitation strategies.