Magnetic resonance imaging features of osteochondral lesions of the talus.

BACKGROUND

Osteochondral lesions of the talus (OLT) traditionally have been thought to occur anterolaterally or posteromedially. Recent studies utilizing magnetic resonance imaging (MRI) have questioned this teaching. The purpose of this study was to use MRI to describe the location, frequency, and morphology of OLT and determine if any correlations exist between lesion location and other data points.

METHODS

The location, frequency, and size of OLT based on a nine-zone grid were recorded on 77 MRI examinations. Lateral ligaments were inspected for evidence of injury. Stability of the lesions was assessed based on four MRI criteria: presence or absence of cartilage defects, edema-like signal abnormality, T2 bright rim, and/or subchondral cysts. Demographic data including patient age, injury mechanism, and chronicity were recorded. An ANOVA model was used to determine if statistical differences existed between lesion size and location. Pearson correlation coefficients were used to examine any association between lesion location and demographic data.

RESULTS

Most of the lesions were located medially and centrally on the talar dome (54.5%), with the second highest frequency found laterally and centrally (31.2%). With the numbers available there was no statistical difference between the size of the lesions based on location. No strong correlations were found between lesion location and demographic data.

CONCLUSION

This study refutes traditional teachings regarding the location of OLT and supports recent studies showing that most lesions are located medially and centrally on the talar dome.