Association Between MRI-Based Cartilage Repair Morphology and Clinical Outcomes After Osteochondral Autograft Transfer of the Talus.

Abstract

Background: Osteochondral lesions of the talus (OLT) represent a challenging ankle pathology that may lead to persistent pain, functional impairment, and progressive joint degeneration. Open transmalleolar osteochondral autograft transfer (OAT) is a well-established treatment option for selected lesions; however, the relationship between postoperative magnetic resonance imaging (MRI)-based cartilage repair morphology and clinical outcomes remains incompletely understood.

Methods: A retrospective review was performed of 17 patients who underwent open transmalleolar OAT for symptomatic OLT between May 2021 and March 2025, with a mean follow-up of 20.8 months (range, 6-34 months). Clinical outcomes were assessed using the visual analogue scale (VAS) and the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. Postoperative cartilage repair morphology was evaluated using MRI and graded according to the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART 2.0) scoring system. MRI examinations were independently reviewed by 2 blinded musculoskeletal radiologists, and the mean MOCART 2.0 score was used for final analysis. Associations between clinical and radiologic parameters were analyzed using Spearman rank correlation.

Results: Significant postoperative clinical improvement was observed. Mean VAS scores decreased from 6.6 ± 1.5 preoperatively to 1.7 ± 1.3 at final follow-up (P < .001), whereas mean AOFAS scores increased from 58.4 ± 8.0 to 88.3 ± 9.3 (P < .001). Postoperative MRI demonstrated a mean MOCART 2.0 score of 70.4 ± 9.7, indicating satisfactory structural cartilage repair. Interobserver reliability for MOCART 2.0 scoring was excellent (ICC = 0.92). No significant correlations were identified between MOCART 2.0 scores and clinical outcome measures or patient-related variables.

Conclusion: Open transmalleolar OAT provides significant clinical improvement in carefully selected patients with OLT. However, postoperative MRI-based cartilage repair morphology assessed by MOCART 2.0 does not appear to directly correlate with clinical outcomes, suggesting that structural repair and patient-reported recovery may represent distinct dimensions of treatment response.

Level of evidence: Level IV, retrospective review.