Comparison of symptomatic unstable ankle with and without os subfibulare.

ABSTRACT

BACKGROUND: This study aimed to compare the patients background, clinical scores, condition of the lateral ligament, mechanical instabilities, and chondral lesions in ankles with symptomatic os subfibulare compared to those in ankles with chronic lateral instability without os subfibulare. METHODS: Of the 212 ankles with a chronic lateral instability that were surgically treated, 72 ankles had an os subfibulare. All ankles were examined by arthroscopy during surgery. Age, sex, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale scores, remnant condition of the lateral ligaments, and chondral lesions were compared between ankles with symptomatic os subfibulare and ankles with chronic lateral instability without os subfibulare. RESULTS: There were no statistically significant differences between the groups in terms of the sex ratio (males females, 3537 vs. 5387, n.s.) and the AOFAS Ankle-Hindfoot Scale scores (median; 75 vs. 77, n.s.). There were statistically significant differences in patient age (median 20 vs. 24.5 years, p < 0.01), talar tilt angle (median 9.0° vs 12.0°, p < 0.01), anterior drawer distance (6.2 vs. 7.0 mm, p < 0.01), chondral lesions (G0G1G2G3, 3521665 vs. 40442729, p < 0.01), condition of the anterior talofibular ligament (intact repairable remnant poor remnant, 0702 vs. 111227, p < 0.01), and condition of the calcaneofibular ligament (intact repairable remnant poor remnant, 44262 vs. 773528, p < 0.01) between the groups. CONCLUSION: This study suggests that the condition of the lateral ligaments including mechanical instability and cartilage of the ankle were less severe in the ankles with symptomatic os subfibulare than in those with chronic lateral instability without os subfibulare. The patients' age was lower in the ankles with symptomatic os subfibulare than in those with chronic lateral instability without os subfibulare. The clinical scores and gender ratio were not statistically different between the group.