Longitudinal Trajectories of Pain and Function Improvement Following Total Knee Replacement

ObjectiveUp to 30% of patients experience persistent pain and functional limitations following total knee replacement (TKR). Rapid symptom relief in the early postoperative period may be linked to longer-term outcome improvements. We sought to identify early improvement trajectories and to identify risk factors for suboptimal outcomes.MethodsWe used data from the Adding Value in Knee Arthroplasty (AViKA) Cohort study, a prospective longitudinal study of patients with knee osteoarthritis who underwent TKR. We assessed pain and function using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). We used group-based trajectory modeling to identify distinct patterns of pain and function improvement over 6 months. We assessed the association between these early improvement trajectories and 24-month outcomes, including pain, function, and satisfaction.ResultsWe analyzed data from 107 subjects. Mean baseline WOMAC pain and function scores were 42 (SD 17) and 44 (SD 15), respectively (0-100; 100 = worst). We identified two pain-improvement trajectories (suboptimal vs optimal improvement) and two function-improvement trajectories (suboptimal vs optimal improvement). Greater pain catastrophizing, worse mental health status, and use of a supportive device prior to TKR were associated with being in a suboptimal trajectory. Recipients of TKR in the suboptimal trajectories had higher pain, high functional disability, and lower satisfaction at 24 months post-TKR.ConclusionPatients with slower improvement over the first 6 months post-TKR had worse outcomes at 24 months, suggesting that this early postoperative period may represent a window during which interventions aimed at speeding recovery may improve long-term TKR outcomes.