Preoperative clinical and imaging factors associated with arthroscopically confirmed occult syndesmotic instability in patients undergoing surgery for osteochondral lesions of the talus

Aims Osteochondral lesions of the talus (OLTs) are common ankle disorders. Recent clinical observations suggest that a subset of patients with OLTs also exhibit occult syndesmotic instability (OSI) intraoperatively, implying a potential association between the two conditions. This study aimed to investigate the potential clinical association between OLTs and OSI, and to identify preoperative factors associated with OSI in patients with OLTs. Methods A retrospective review was performed on patients diagnosed with OLTs who underwent ankle arthroscopy between January 2021 and June 2023. Based on arthroscopic probe assessment of distal tibiofibular stability, patients were divided into an OLT with OSI group and an OLT without OSI group. Demographic characteristics, arthroscopic findings, imaging results, physical examination outcomes, and preoperative American Orthopaedic Foot and Ankle Society ankle-hindfoot and visual analogue scale scores were compared between groups. Univariate and multivariate logistic regression analyses were performed to identify independent predictors, and receiver operating characteristic analysis determined diagnostic cut-off values. Results Among 175 patients with OLTs, 36 (20.6%) demonstrated OSI. Univariate analysis showed that BMI, symptom duration, height of syndesmotic fluid, lesion size, presence of osteophytes, and Bassett’s ligament hypertrophy were significantly associated with OSI. Multivariate analysis identified higher BMI (odds ratio (OR) 1.811 (95% CI 1.418 to 2.312); p < 0.001), presence of osteophytes (OR 0.260 (95% CI 0.087 to 0.775); p = 0.016), and Bassett’s ligament hypertrophy (OR 0.108 (95% CI 0.030 to 0.387); p = 0.001) as independent associated factors for OSI. Conclusion In patients with OLTs, BMI above 25.6 kg/m 2 , presence of osteophytes, and Bassett’s ligament hypertrophy were associated with intraoperative OSI, although these exploratory findings warrant further prospective investigation and external validation. Cite this article: Bone Joint J 2026;108-B(10):1265–1272.