Primary Tibiotalocalcaneal Nailing vs Open Reduction and Internal Fixation for Fragility Ankle Fractures in Older Adults: A Markov Model

Background: Fragility ankle fractures are common in the elderly population. The cost-effectiveness of primary tibiotalocalcaneal (TTC) nailing compared with open reduction and internal fixation (ORIF) in this population remains unclear. Methods: We constructed a Markov cohort model with a 4-year time horizon to compare TTC nailing vs ORIF for fragility ankle fractures in patients aged 75 years and older. All complication rates were derived from the McDonald et al's (2025) systematic review and meta-analysis. Costs were in 2024 US dollars with 3% annual discounting for costs and outcomes. Probabilistic and deterministic sensitivity analyses were performed. Results: In the base case, ORIF yielded 3.210 quality-adjusted life years (QALYs) (95% credible interval [CrI] 2.785-3.584) at $30 091 (95% CrI $21 426-$40 852) compared with 3.207 QALYs (95% CrI 2.783-3.581) at $33 583 (95% CrI $23 741-$45 447) for TTC nailing. ORIF dominated incremental cost (+$3492, 95% CrI -$11 467 to +$18 273) and incremental QALYs (-0.003, 95% CrI -0.009 to +0.002). The cost differential was driven by the $3000 higher index procedure cost for TTC, partially offset by lower superficial infection (2.1% vs 10.2%). Probabilistic sensitivity analysis demonstrated 33% probability of cost-effectiveness at $100 000/QALY. All 4 scenario analyses confirmed that ORIF dominated. Conclusion: Under McDonald's pooled estimates, TTC nailing is dominated by ORIF for fragility ankle fractures in older adults. The lower superficial infection rate with TTC does not offset its higher procedure cost and higher rates of nonunion and hardware failure. These findings support ORIF as the preferred strategy from a cost-effectiveness standpoint, although the small incremental differences should be considered alongside clinical factors when selecting treatment. Level of Evidence: Level IV, economic modeling.