Realignment Osteotomy in Fibular Malunion

Abstract

Category: Ankle Introduction/Purpose: The exact incidence of distal fibula malunions after fibular reconstructions is not known, but incidence up to 33% is described in the literature. The most frequent malunions of the fibula are shortening and malrotation, resulting in the widening of the ankle mortise and talar instability. It has been demonstrated that substantial fibular displacement may substantially increase the contact pressures in the ankle joint. Therefore distal fibular malunion is a risk factor for development of posttraumatic ankle osteoarthritis. The objectives of this study were to (1) describe our treatment algorithm and surgical technique in patients with posttraumatic fibula malunions; (2) determine intra- and postoperative complications rates, and (3) to describe mid-term clinical and radiological outcomes and quality of life. Methods: 19 consecutive patients (11 male, 8 female, mean age 42 years, range 19 – 68) with symptomatic fibular malunions were included into this prospective study. The initial injury was Weber B and C fracture in 7 and 12 ankles, respectively. The mean time between the injury and reconstructive surgery was 17 months (range 6 – 101). In all patients a z-shaped osteotomy of the fibula was performed to achieve the appropriate length/rotation of the fibula. Fixation was performed using a plate. If necessary, supramalleolar and inframalleolar deformities were corrected by supramalleolar tibial and calcaneal osteotomies, respectively. Prior to the osteotomies an anterior ankle arthroscopy was performed in all patients. All patients were evaluated pre- and postoperatively (mean follow-up 4.9 years, range 3.2 – 6.7). Radiological outcomes were assessed using standardized weight- bearing radiographs. Clinical outcomes were assessed using visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale, and SF-36 questionnaire. Results: There were no intraoperative complications. In two patients early wound healing problems were observed, and resolved with i.v. antibiotics. Osseous healing was observed in all ankles within 10 weeks after surgery. The length and rotation of the fibula was improved in all patients, according to Weber criteria. All patients experienced significant pain relief (VAS: 6.5 ± 1.1 to 0.9 ± 0.8, P < 0.001) and functional improvement (AOFAS hindfoot scale: 48.4 ± 14.5 to 85.7 ± 7.4, P < 0.001; ROM:37° ± 6° to 46° ± 5°, P < 0.001). The SF-36 score also significantly increased in all 8 subgroups. In 11 patients hardware was removed due a discomfort after a mean of 11.8 months (range 7.2 – 22.8). Conclusion: A z-shaped osteotomy is an efficient and successful method to restore fibula length and rotation in patients with posttraumatic malunion. Our findings in this series confirm that this realignment surgery results in significant pain relief and functional improvement.