Treatment of talus osteochondral defects in chronic lateral unstable ankles: small-sized lateral chondral lesions had good clinical outcomes

Abstract

Purpose: To assess and compare the clinical and MRI outcomes of patients with talus osteochondral defect (OCD) and patients without OCD in a cohort with chronic lateral ankle instability.

Methods: All patients who underwent open or arthroscopic anterior talofibular ligament repair of the lateral ligament complex by a single surgeon were included in this study. Ankle arthroscopic surgery was initially performed to manage any intra-articular OCD, including debridement and microfracture. Functional scores (AOFAS, Karlsson score) and Tegner activity level scores were determined. An MRI scan was performed at follow-up to assess talus OCD after treatment. Spearman's correlation coefficients were calculated between functional scores and various factors.

Results: A total of 104 patients with chronic ankle instability were included in this study. Among them, 33 patients had cartilage injury on the talus (OCD group), and the other 71 patients had no cartilage injury (control group). After surgery, there was a significant increase in the AOFAS scores (p < 0.001), the Karlsson scores (p < 0.001), and the Tegner activity scores (p < 0.001) in both the OCD group and the control group. However, there was no significant difference in the AOFAS scores (90.7 ± 6.6 vs. 92.5 ± 8.5; n.s.), the Karlsson scores (89.7 ± 9.3 vs. 91.2 ± 9.1; n.s.), or the Tegner activity scores (5 vs. 6; n.s.) between the OCD group and the control group postoperatively. In the OCD group, there was a significant negative association between the functional scores (AOFAS, Karlsson score, or Tegner score) and the number of intra-articular lesions. For the lateral OCD, the mean lesion area significantly decreased from 49.0 ± 10.7 mm² preoperatively to 18.3 ± 13.1 mm² at the final follow-up (p < 0.001).

Conclusion: No significant difference in functional outcomes was found between the OCD group and the control group postoperatively. Arthroscopic microfracture is a good option for the long-term treatment of lateral talus OCD.

Level of evidence: III.

Keywords: Ankle instability; Functional outcomes; MRI; Microfracture; Osteochondral defect.