A comparison of 2 continuous passive motion protocols after total knee arthroplasty: a controlled and randomized study.

Effect of continuous passive motion (CPM) protocols on outcomes after total knee arthroplasty. In this prospective randomized controlled study, 147 patients were assigned to 1 of 3 treatment groups: CPM from 0 degrees to 40 degrees and increased by 10 degrees per day, CPM from 90 degrees to 50 degrees (early flexion) and gradually progressed into full extension over a 3-day period, and a no-CPM group. The CPM was administered twice a day for 3 hours over a 5-day period. All patients participated in the same postoperative physiotherapy program. Patients were assessed preoperatively, day 5, 3 months, and 1 year postoperatively. The early flexion group had significantly more range of flexion than both the standard and control groups at day 5. There was no significant difference between the groups for any other variable tested at any time frame. Key words: total knee arthroplasty, CPM, rehabilitation, outcomes.