Relationship between talar dome osteochondral lesions and medial malleolus fractures, and their diagnostic significance for occult medial malleolus fractures

OBJECTIVE: This study aimed to investigate the potential correlation between talar dome osteochondral lesions (TDOCL) and medial malleolus fractures and assess the diagnostic significance of TDOCL identified on standard anteroposterior (AP) ankle radiographs for detecting occult medial malleolus fractures. METHODS: A retrospective analysis was conducted on 452 patients with ankle fractures, including 13 cases of occult medial malleolus fractures, treated at Ningde Hospital of Traditional Chinese Medicine between January 2015 and August 2024. For detailed analysis, the talar dome on the AP radiographic view was vertically split into three equal sections. Any definite or suspected TDOCL identified on the AP view was recorded and classified based on location. Computed tomography (CT) imaging was used as the reference standard for diagnosing TDOCL. For every patient, data including sex, age, injured side, diagnostic findings, presence or absence of TDOCL, and lesion location were independently collected. The false-negative and false-positive rates of X-ray detection of TDOCL were calculated, and the association between TDOCLs and medial malleolus fractures was analyzed. Diagnostic performance measures, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR+), were calculated for medial TDOCL in predicting occult medial malleolus fracture. RESULTS: Medial TDOCL and female sex were identified as independent risk factors for medial malleolus fracture. For occult medial malleolus fracture, medial TDOCL detected on AP radiographs demonstrated a sensitivity of 38.5%, specificity of 100%, PPV of 100%, and NPV of 98.2%. LR+ could not be calculated due to 100% specificity. CONCLUSIONS: Medial TDOCL is strongly associated with medial malleolus fracture and may serve as a potential warning indicator for occult injury. Clinicians should integrate radiologic findings with physical examination and consider targeted CT imaging for confirmation. These findings are hypothesis-generating and require further validation in prospective studies.