Anatomic location and morphology of symptomatic, operatively treated osteochondral lesions of the talus.

BACKGROUND: Historically, osteochondral lesions of the talus (OCLTs) were thought to occur most commonly in the anterolateral and posteromedial talar dome; however, new classification systems are able to describe OCLT location more precisely. A recent magnetic resonance imaging (MRI) study introduced a novel nine-zone anatomic grid of the talar dome, demonstrating that most OCLTs occur in the central portion of the medial and lateral talar dome, with medial lesions being more common as well as larger in depth and surface area. The current study sought to determine if similar location and morphology patterns were consistent in symptomatic, operatively treated OCLTs.
MATERIALS AND METHODS: The preoperative MRI images of 65 consecutive patients who underwent operative management for symptomatic OCLTs at a single institution were reviewed using a previously described nine-zone anatomic grid of the talar dome to determine location frequency, morphology, and Hepple et al. MRI staging classification characteristics. All patients were active-duty service members in the United States Armed Forces. The cohort consisted of 60 (92%) males and 5 (8%) females with an overall mean patient age of 34 (range, 19 to 58) years. Statistical analyses were performed, and significant differences are reported.
RESULTS: The most common location for symptomatic, operatively treated OCLTs was the central third of the lateral talar dome, followed by the central third of the medial talar dome. Anterolateral and posteromedial lesions accounted for relatively few OCLTs. Compared with lateral OCLTs, medial OCLTs were significantly larger in transverse and anteroposterior diameters and surface area, but no significant differences existed with regard to lesion depth. Overall, the majority of lesions were MRI stage II; however, stage II lesions were more likely located laterally, whereas stage III lesions were more likely located medially.
CONCLUSIONS: With regard to symptomatic, operatively treated OCLTs, the results of the current study parallel current evidence that posteromedial and anterolateral OCLTs are not the most common locations of OCLTs. As well, medial OCLTs were larger in surface area than lateral OCLTs, but no differences existed with regard to lesion depth. It is interesting that operatively treated OCLTs were twice as commonly located in the centrolateral third rather than the centromedial third of the talar dome.