Randomized, prospective, monocentric study to compare the outcome of continuous passive motion and controlled active motion after total knee arthroplasty

BACKGROUND: The number of patients requiring a total knee arthroplasty (TKA) is increasing and postoperative care is an important factor for the recovery of knee function. It is discussed controversially, if the benefits of controlled active motion (CAM) therapies are comparable to continuous passive motion (CPM) therapies. OBJECTIVE: Comparison of postoperative outcomes using a device in CAM and CPM settings, in addition to standard physiotherapeutical exercises immediately after TKA. METHODS: TKA patients were randomized to either CAM or CPM therapy performed with an identical device (ARTROMOT® ACTIVE-K, Ormed GmbH). All patients received an additional physiotherapeutic program. Pain, knee associated problems (KOOS), active range of motion (ROM), and adverse events were documented before surgery, during the stationary stay and after an outpatient period. RESULTS: We included 50 patients (70 ± 8 years). During the postoperative period, KOOS scales improved significantly in both groups, but the CAM group showed a significantly better improvement of pain and quality of life scale. Furthermore, postoperative course of pain intensity and knee flexion was significantly better in the CAM group. CONCLUSIONS: CAM and CPM lead to significant improvements after TKA, but CAM shows better results in terms of flexion, pain and quality of life.