Immediate continuous passive motion after internal fixation of an ankle fracture

Surgical treatment is usually mandatory in displaced bimalleolar and trimalleolar fractures. Some authors have recommended early mobilization of the ankle joint after surgical treatment of these lesions. In this study, we evaluate the effect of immediate postoperative continuous passive motion in the management of displaced bimalleolar and trimalleolar fractures treated surgically.

Two series of 22 patients each, who had had a Weber type A, B or C ankle fracture treated surgically, were followed up at least 10 years after the injury. In the first series, immediately after surgery, a continuous passive motion machine was applied to the operated ankle for 3 weeks, whereas in the second series, after surgery a plaster splint or a plaster cast was applied for 3 weeks.

At follow-up, all patients were evaluated clinically and radiographically using the AOFAS Ankle Hindfoot Score System (Kitaoka, Foot Ankle 15:349-353, 1994). The average final score for the first series of patients was 95.7 points (range 87-100 points, standard deviation 3.42 points). Of this series, at radiographic examination, in two patients we observed minor signs of osteoarthritis of the ankle joint. The average final score for the second series was 88 points (range 68-100 points, standard deviation 10.60 points). At radiographic examination, in six patients we observed minor signs of osteoarthritis of the ankle joint, whereas in another one the osteoarthritis was severe.

Continuous passive motion started immediately after surgery seems to be an effective method both for allowing complete and quick recovery of the range of motion of the ankle and for reducing the risk of early degenerative joint disease. Immediate passive ankle motion can be applied only after adequate reduction and stable internal fixation.