Continuous Active Motion Versus Continuous Passive Motion for Rehabilitation of Patients After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Introduction: Rehabilitation following total knee arthroplasty (TKA) includes various therapeutic interventions, such as continuous active motion (CAM) and continuous passive motion (CPM). This meta-analysis aimed to compare the effects of CAM and CPM on pain, function, and range of motion post-TKA, focusing on the early postoperative period. Methods: A systematic literature search was conducted in databases including Medline, Cochrane Library, Embase, and CINAHL to identify randomized controlled trials (RCTs) comparing CAM and CPM post-TKA. Studies were required to include at least two postoperative measurements and combine the interventions with standard physiotherapy. The methodological quality of the included studies was assessed using the JBI appraisal tool, and statistical analysis was performed on suitable studies. Results: Seven RCTs involving 501 patients were included. Meta-analysis indicated significant pain reduction and improved functional outcomes with CAM compared to CPM, particularly in postoperative pain assessments. CAM showed advantages in functional tests, including the Sit-to-Stand and Timed-Up-and-Go tests. However, no significant differences were found for active and passive range of motion (ROM). Patient-reported outcome measures (PROMs) showed high heterogeneity, limiting clear conclusions. Conclusions: CAM demonstrates significant benefits in pain reduction and functional recovery compared to CPM following TKA. However, variability in outcome measures and intervention protocols limits comparability across studies and therefore generalizability. CAM's requirement for active patient engagement may present practical challenges, while CPM's standardization allows for easier integration into routine postoperative care.