Is an unresected subtalar joint a cause of failure in tibiotalocalcaneal arthrodesis with a nail?

Aim: In this study, we aimed to evaluate clinical and functional outcomes of tibiotalocalcaneal arthrodesis (TTCA) using intramedullary nailing (IMN) without cartilage resection of the subtalar (ST) joint. Methods: 22 ankles of 21 patients (one patient was bilateral), who underwent TTCA using IMN without cartilage resection of the ST joint in our clinic between January 2013 and December 2022 were retrospectively analyzed. Data including demographic and clinical characteristics of the patients, etiology, Kellgren-Lawrence classification, postoperative fusion rate, fusion status and complications were recorded. The European Quality of Life 5 Dimensions (EQ-5D) scores were also noted. Results: Ten patients were male and 11 were female. The mean age was 54.7±14.9 years. The mean follow-up was 46.4±19.1 months. The mean best health status score of the EQ-5D (EQ-VAS) was 73.9±16.5. Tibiotalar (TT) fusion occurred in all patients, while ST fusion was not achieved in ten patients. Four of these patients underwent secondary procedures, while no intervention was planned for the other six patients because they were asymptomatic. Conclusions: This study has demonstrated that unresected subtalar articular cartilage leads to a significant rate of ST fusion failure. Nevertheless, the possibility of partial fusion or fibrous fusion at the reaming site is thought to be the reason for the high rate of asymptomatic patients.