Fixing geriatric ankle fractures: fibular nail versus locking plate in a prospective multicenter study

Elderly patients with unstable ankle fractures face a high risk of wound and implant-related complications after open reduction and internal fixation (ORIF). Less invasive intramedullary fibular nail (FN) fixation may reduce soft-tissue trauma and enable earlier mobilization. In this prospective multicenter trial with pseudorandomized allocation and protocol-permitted crossover, 55 geriatric multimorbid patients (Charlson Comorbidity Index ≥ 4; mean age FN 79 ± 8 vs. ORIF 74 ± 8 years; p = 0.053) were treated with FN (n = 39) or ORIF (n = 16). Primary outcomes were operative time, fluoroscopy time, hospital stay, weight-bearing at discharge, complications, and functional scores (AOFAS, OMAS, Weber) at six weeks and twelve months. FN required more fluoroscopy time (p = 0.011), while operative duration and hospital stay were comparable (p = 0.176, p = 0.520). Full weight-bearing at discharge was more frequent after FN (62% vs. 0%; p < 0.001). At six weeks, FN patients achieved higher functional scores (AOFAS p = 0.041; OMAS p = 0.027), but at twelve months no differences remained (AOFAS p = 0.404; OMAS p = 0.288; Weber p = 0.585). Radiographic malalignment was more common after FN (46% vs. 13%; p = 0.031). Distal screw loosening at twelve months occurred more often after FN (80% vs. 11%; p = 0.005) but was mostly asymptomatic. Earlier mobilization observed after FN in our study primarily reflects the permissive postoperative weight-bearing protocol rather than an inherent biomechanical advantage of the implant. At twelve months, functional outcomes were equivalent, underscoring that protocol-driven early loading, not implant design, explains early differences.