Background: Transfibular total ankle arthroplasty (TAA) necessitates a fibular osteotomy followed by reduction and fixation after component implantation. Although this approach offers advantages such as adjusting fibular length and alignment, there is concern about the potential complication of fibular nonunion. The purpose of this study is to determine the incidence of radiographic nonunion of the fibular osteotomy in a large single-surgeon series.
Methods: Retrospective review was performed of all transfibular TAA performed by a single surgeon from 2012 to 2022, and patients with minimum 2-year radiographic follow-up were included. Fibular osteotomy fixation was achieved with a lateral locked plate. Weightbearing ankle radiographs were analyzed at 3, 6, 12, and 24 months postoperatively for evidence of healing based on mature bridging bone across the osteotomy. Secondary analyses at 3 and 6 months were performed based on patient age (<55 vs 55 ≥ years old), history of diabetes, and smoking status.
Results: A total of 406 ankles (380 patients) with a mean age of 60 years (range, 23-85) were included in this analysis. Incomplete healing of the fibular osteotomy was observed in 16.3% of ankles at 3 months, 5.9% at 6 months, and 1.0% at 12 and 24 months. Rates of union at 3 and 6 months were not statistically different based on patient age, history of diabetes, or smoking status (all P > .05). Four (1.0%) nonunions were observed in total: 2 cases were symptomatic and healed following revision fixation with bone grafting.
Conclusion: In this large series of consecutive transfibular TAA, most patients had healed their fibular osteotomy by 3 months. There was no association between osteotomy healing and patient age, smoking status, or diabetes at 3 and 6 months postoperatively, and the overall incidence of fibular nonunion was 1%. These results should be reassuring to surgeons concerned about this potential complication when considering transfibular approach for TAA.
Level of evidence: Level IV, case series.
Keywords: fibular osteotomy; radiographic union; trabecular metal; transfibular total ankle.