This study was conducted to compare postoperative total knee arthroplasty rehabilitation protocols. The hypothesis of this study was that patients undergoing total knee arthroplasty could achieve range of motion and hospital discharge in the same period using a postoperative rehabilitation protocol that did not use a continuous passive motion machine. This randomized prospective study compared 46 total knee arthroplasties in which a continuous passive motion machine was used with 37 total knees that were rehabilitated with early passive flexion of the knee (named drop and dangle protocol). Postoperative physical therapy regimens were otherwise the same for both groups. Surgical technique was the same for both groups except for closure which was performed in the drop and dangle group with the knee at 90 ° to 95 ° flexion. Only patients with osteoarthritis were included in the study, and in both groups of patients received the same prosthetic components. Patients in the drop and dangle group were discharged from the hospital 1 day earlier (p = 0.01) and had a statistically better extension range of 2.8 ° at 6 months (p = 0.03). Knees in the drop and dangle group had less drainage (p = 0.06). Range of motion and hospital discharge can be achieved in a similar time interval with the drop and dangle technique as with using a continuous passive motion device, and that such a device is not required for postoperative knee rehabilitation.
From the University of Southern California Center for Arthritis and Joint Implant Surgery, University of Southern California University Hospital, Los Angeles, CA.
Supported in part by Intermedics Orthopedics.
Reprint requests to Edward J. McPherson, MD, University of Southern California Center for Arthritis and Joint Implant Surgery, University of Southern California University Hospital, 1500 San Pablo Street, Los Angeles, CA 90033.