Use of Continuous Passive Motion in the Postoperative Treatment of Intra-Articular Knee Fractures

Background: The use of continuous passive motion in the postoperative treatment of intra-articular fractures around the knee is increasing. The purpose of this study was to determine the effects of a continuous passive motion device on knee range of motion after operative treatment of intra-articular fractures around the knee. Methods: Forty patients with intra-articular fractures of either the proximal part of the tibia or the distal end of the femur were prospectively randomized to the use of continuous passive motion or standardized physical therapy in the immediate postoperative period for forty-eight hours. The primary outcome was knee range of motion. Secondary outcome measures included pain scores, Lower Limb Outcomes Questionnaire scores, and Short Musculoskeletal Function Assessment scores. Evaluations were conducted at forty-eight hours, two weeks, six weeks, three months, and six months postoperatively. Results: There was no significant difference in knee extension between the groups at any time point measured. Knee flexion was significantly greater at forty-eight hours in the group managed with the continuous passive motion device than in the group managed without the continuous passive motion device (p < 0.005). However, there was no significant difference in knee flexion at any other time point. There was no significant difference in knee pain at forty-eight hours between groups. Six (30%) of twenty patients were unable to tolerate the use of the continuous passive motion device. There were no significant differences in overall complications. Conclusions: The results of this study suggest that the use of continuous passive motion in the immediate postoperative period following the treatment of intra-articular fractures offers no benefit with regard to knee motion at six months and is not tolerated by all patients.