The Impact of Preoperative Activity on Postoperative Outcomes in Total Knee Arthroplasty: A Retrospective Cohort Analysis

Background Preoperative activity levels may influence postoperative outcomes in total knee arthroplasty (TKA) patients. This study investigates how preoperative activity impacts the risks of revision surgery and sepsis at one, two, and three years following TKA. Methods A retrospective cohort analysis was conducted using a large national database. Adult patients undergoing primary TKA between January 1, 2010, and December 31, 2023, were included. Patients were stratified into “active” and “inactive” cohorts based on documented preoperative physical activity within six months before surgery. Outcomes assessed included revision surgery, hardware failure, hospital readmission, periprosthetic fracture, opioid abuse, and postoperative stiffness or limited range of motion. Risk ratios and 95% confidence intervals were calculated, with significance defined as P < 0.05. After propensity score matching, 4,090 patients were included (2,045 active and 2,045 inactive). Results At one year postoperatively, active patients had a lower risk of revision surgery ( P = 0.047), with a nonsignificant trend toward reduced postoperative stiffness ( P = 0.057). At two years, activity was associated with both a reduced risk of revision surgery ( P = 0.008) and an increased risk of hardware failure ( P = 0.008). At three years, this pattern persisted, with lower revision risk ( P = 0.007) but higher hardware failure risk ( P = 0.026). There were no significant differences observed in hospital readmission, periprosthetic fractures, or opioid abuse across time points. Conclusions Preoperative physical activity is associated with both protective and adverse outcomes following TKA. Higher activity levels were consistently linked to reduced risk of revision surgery up to three years postoperatively as well as an increased risk of hardware failure. These findings highlight the complex role of preoperative activity in shaping postoperative trajectories and underscore the need for further research to clarify mechanisms driving these associations. Level of Evidence Level III, retrospective cohort study, prognostic.