Physical activity and health-related quality of life of patients with chronic knee pain after total knee arthroplasty: analysis of the pep-talk trial

Abstract INTRODUCTION This study aimed to examine how physical activity and health-related quality of life (HRQoL) evolved over the first year after total knee replacement (TKR) for patients with and without post-operative chronic knee pain. METHODS 83 adults participating in the PEP-TALK, a RCT testing the effectiveness of a behaviour change physiotherapy intervention versus usual rehabilitation post-primary TKR, were analysed. UCLA Activity Score and EQ-5D-5L values for participants with and without chronic knee pain (14 points or lower in the Oxford Knee Score Pain Subscale at six months post-TKR) were compared at six and 12 months post-TKR. We evaluated recovery trajectory those with or without chronic pain at these time points. RESULTS Participants with chronic knee pain, UCLA Activity Score remained unchanged between baseline to six months (mean: 3.8 to 3.8), decreasing at 12 months (mean: 3.0). Those without post-operative chronic knee pain reported a improvement in physical activity from baseline to six months (mean: 4.0 vs 4.9), plateauing at 12 months (mean: 4.9). Participants with chronic knee pain reported lower baseline HRQoL, although both groups improved mean health utility over one year. Of participants who were not defined as being in chronic pain at six months, 8.5% returned to a chronic pain categorisation by 12 months. CONCLUSION People with chronic knee pain post-TKR report poorer physical activity and HRQoL scores post-operatively. Monitoring outcomes longer than six months may be indicated as those without chronic knee pain initially post-TKR remain at risk of reverting to chronic knee pain 12 months post-TKR.