Baseline Predictors of Functional Recovery After a 12-Week Physiotherapy Rehabilitation Program in Patients With Grade II Knee Osteoarthritis: A Secondary Analysis of Trial Data

Abstract

Background: Functional recovery after rehabilitation for Grade II knee osteoarthritis varies across patients, even when similar physiotherapy protocols are used. Identifying recovery patterns across pain, stiffness, function, and knee mobility may help clinicians interpret treatment response beyond simple group comparison. Objective: To examine 12-week recovery gradients in patients with Grade II knee osteoarthritis receiving physiotherapy-based rehabilitation and to establish a secondary-analysis framework for evaluating baseline predictors of functional recovery. Methods: This secondary analysis used data from a single-blinded randomized clinical trial including 84 participants aged 40–60 years with Grade II knee osteoarthritis. Participants received either a Macquarie Injury Management Group protocol with conventional physiotherapy or a targeted knee exercise program with conventional physiotherapy. Outcomes were assessed at baseline, 8 weeks, and 12 weeks using the Numeric Pain Rating Scale, WOMAC pain, WOMAC stiffness, WOMAC physical function, and goniometric knee flexion and extension. Recovery gradients were calculated from baseline to 12 weeks using available aggregate data. Results: Pain improved by 3.93 points in the MMG protocol group and 4.40 points in the targeted knee exercise group. WOMAC pain improved by 7.62 and 9.69 points, WOMAC stiffness by 3.62 and 4.76 points, and WOMAC function by 21.40 and 19.81 points, respectively. Knee extension gain was 5.17° in the MMG protocol group and 10.14° in the targeted exercise group, while knee flexion gain was 17.95° and 23.19°, respectively. Conclusion: Both rehabilitation approaches produced meaningful 12-week improvement, with stronger symptom and mobility gradients observed after targeted knee exercise. Participant-level modelling is required to confirm independent baseline predictors of recovery.