Value of continuous passive motion in total knee arthroplasty

Two methods of rehabilitation after 91 total knee arthroplasties in 74 patients were reviewed. Patients in each group were well matched for age, sex, and diagnosis. Forty-four knees in 39 patients were treated with conventional physiotherapy, consisting of 3 days of immobilization followed by a program of active assisted range-of-motion exercises. Forty-seven knees in 41 patients were placed in a continuous passive motion machine immediately after operation. Other aspects of preoperative, intraoperative, and postoperative care were identical in both groups. Patients in the continuous passive motion group were found to have a lower incidence of complications, especially of wound healing problems and thromboembolic disease. Analgesic use in patients in the continuous passive motion group was reduced. Straight leg raising was achieved slightly earlier in patients in the continuous passive motion group (4.9 days) compared with patients not treated with continuous passive motion (5.2 days). Although the range of motion of the knee at discharge from the hospital in patients in the continuous passive motion group was greater (91 degrees) compared with patients not treated with continuous passive motion (81 degrees), the range of motion in both groups at ultimate follow up was equivalent. However, when knee-rating scores were considered, patients treated with continuous passive motion averaged 9 points higher on a 100-point scale than patients not treated with continuous passive motion. In addition, the length of hospital stay for patients in the continuous passive motion group was 2.1 days shorter. We concluded that continuous passive motion was an effective adjunct to physiotherapy in the postoperative care of patients undergoing total knee arthroplasty.(ABSTRACT TRUNCATED AT 250 WORDS)