Lengthening osteotomy of the fibula in treatment of treating lateral malleolar malunon

Abstract

Objective To investigate the therapeutic effect of lengthening and rotational osteotomy of the fibula for lateral malleolar malunion. Methods Twenty-three patients who had suffering from the traumatic arthritis of ankle were due to lateral malleolar malunion treated with lengthening and rotational osteotomy from October 2005 to July 2008. Special radiographs were use to fully detect the extent of shortening and rotation of the fibula. The Lengthening and rotational osteotomy could be conducted with a special compression/distraction device and bone graft. The function of the ankles was evaluated by the American Orthopedic Foot Ankle Society (AOFAS) scoring system. Serial radiographs of the ankle were made to assess the bone healing and changes of posttraumatic osteoarthritis. Results Seventeen of 23 patients were followed up, with a mean 29.1 months (12-45 months). All the fractures were healed. The mean bone healing time was 13.3 weeks (11-16 weeks) and the mean time of total weight-bearing was 12.1 weeks (11-15 weeks). The ankle function score had improved from 29 (21-47) preoperatively to 81 (56-91)12 months after the operation. There was 5 in excellent, 8 in good, 3 in mild, 1 in poor, and the rate of good outcomes was 76.5%. After the operation, 1 patient had a skin necrosis around the wound which healed by conservative treatment. A slightly aggravated degeneration of the ankle joint was seen in 2 patients who responded to conservative managements. No failure of the internal fixation was noted in this group. Conclusion The outcomes demonstrate that reconstructive lengthening osteotomy is well worthwhile when there is absent or minimal osteoarthritic change, regardless the time from the original injury. Lengthening of the fibula is an important step in the treatment of the painful ankle when the fibula become shorter after injury, even when degenerative changes of the joint are already present. The lengthening of the fibula could lead to a good outcome in ankle with lateral malleolar malunion. Key words: Ankle injuries; Synostosis; Bone lengthening