Accessibility of the talus through an anterior arthrotomy for treatment of osteochondral lesions using autologous matrix-induced chondrogenesis.

BACKGROUND: Open treatment of osteochondral lesions of the talus (OLTs) using autologous matrix-induced chondrogenesis (AMIC) may require malleolar osteotomy for exposure. This study analysed which OLT locations can be accessed through an anterior arthrotomy without osteotomy. METHODS: Fifty patients undergoing AMIC were retrospectively analysed. Lesion location was measured on MRI as the distance from the anterior cartilage margin to the posterior lesion border relative to talar dome length. Receiver operating characteristic analysis identified the optimal cut-off for predicting osteotomy. RESULTS: Anterior arthrotomy was sufficient in 70% of cases. Lesions treated without osteotomy were more anterior than those requiring osteotomy (65 ± 13% versus 79 ± 11%; p < 0.001). The optimal cut-off was 73.3% (area under the curve, 0.821), with 80.0% sensitivity and 82.9% specificity. Posteromedial lesions showed the highest osteotomy rate. CONCLUSIONS: During AMIC, lesions confined to the anterior three quarters of the talar dome can generally be treated without osteotomy, whereas posterior extension increases osteotomy likelihood.