RESUMEN
PURPOSE: This study evaluated the efficacy of continuous passive motion (CPM) versus conventional physical therapy (CPT) in the early postoperative period following retrograde femoral nailing (RFILN). Based on the principles of operation of CPM, we hypothesized that it would improve knee function and decrease pain after open reduction and internal fixation with a retrograde femoral interlocking nail. PATIENTS AND METHODS: Eighty-eight patients over the age of 18 years who met the inclusion criteria got randomized into one of two groups. The experimental group had CPM, while the control group had CPT. Postoperative knee functions assessed were the degree of knee stiffness, the total arc of motion, and knee pain. Knee stiffness, defined as the range of motion ≤ 90° assessed one week, two weeks, and six weeks postoperatively, while knee pain was measured using the visual analog scale (VAS) on days one, two, three, four, five, six and seven postoperatively. RESULTS: The CPM group had a significantly lower incidence of knee stiffness at one week, two weeks, and six weeks postoperatively than the CPT group (all p < 0.0001). The VAS scores of the CPM group on days one, two, three, four, five, six and seven were significantly lower than those of the CPT group (p < 0.006 for day one and p < 0.001 for the remaining days). Similarly, the total arc of motion gained postoperatively was significantly greater in the CPM group than in the CPT (all p < 0.001). CONCLUSION: The continuous passive motion effectively reduced the number of patients with knee stiffness and knee pain. It increased the total arc of motion in the early postoperative period compared to CPT. Therefore, we recommend CPM for patients undergoing retrograde femoral nailing use in the early postoperative period.