BACKGROUND: The continuous passive motion (CPM) machine is one means by which to rehabilitate the knee after total knee replacement surgery.
PURPOSE: This study sought to determine which total knee replacement patients, if any, benefit from the use of the CPM machine.
METHODS: For the study period, most patients received active physical therapy. Patients were placed in the CPM machine if, on postoperative day 1, they had a range of motion less than or equal to 45° and/or pain score of 8 or greater on a numeric rating scale of 0–10, 0 being no pain and 10 being the worst pain.
RESULTS: Both groups of patients healed at similar rates. The incidence of adverse events, length of stay, and functional outcomes was comparable between groups.
CONCLUSION: Given the demonstrated lack of relative benefit to the patient and the cost of the CPM, this study supported discontinuing the routine use of the CPM.