Location of Talar Osteochondral Defects in Chronic Lateral Ankle Instability in an Asian Population.

Osteochondral defect of the talus is traditionally described to involve the anterolateral and posteromedial portion of the talar dome in patients with chronic lateral ankle instability. Recent studies challenged this notion with advances in preoperative imaging and arthroscopy. Since Asian patients are more prone to ligamentous laxity, we postulate that the morphology and severity of osteochondral defects may be different in this population. Intraoperative records of 272 patients undergoing modified Broström-Gould procedure were reviewed for arthroscopic evidence of osteochondral defects. We characterized the morphology according to an anatomical 9-grid classification. Talar osteochondral defects were seen in 52 (19.1%) patients with a double lesion present in 1 patient. Medial-sided lesions account for nearly 3-quarters (n = 38, 73.1%) of all lesions and tend to be larger (79.4 ± 55.7 mm2 vs 51.0 ± 28.6 mm2, p =.08). There was no osteochondral defect seen in the central zones. There was no significant gender or age differences between patients with medial and lateral lesions. The most commonly performed procedure was microfracture. Osteochondral defects are commonly encountered in our Asian patients undergoing surgery for chronic lateral ankle instability. Contrary to published data, medial lesions are prevalent with no central lesions seen.