MRI Assessment of Autologous Osteochondral Transplantation in Talus: Correlation with Clinical Outcomes and Second look

Sanbiao Liu¹Yunfeng Chu²wen Zhou³Yuxin Yan⁴Yuyi Zhang²Sumeng Chen⁴Lu Bai^4*

• ¹orthopedics, The Fifth Hospital of Wuhan, Wuhan, China
• ²Department of Hand and Microvascular Surgery, Shenzhen Hospital, Peking University, Shenzhen, China
• ³Department of Medical Imaging, Shenzhen Hospital, Peking University, Shenzhen, China
• ⁴Department of Sports Medicine, Shenzhen Hospital, Peking University, Shenzhen, China

Background: Autologous osteochondral transplantation (AOT) is an effective technique for treating complex osteochondral injuries of the talus. However, there is still controversy regarding the imaging assessment of its postoperative efficacy. MRI, as a non-invasive examination, is the primary method for evaluating surgical outcomes, while invasive secondary arthroscopic surgery provides a more direct and accurate evaluation of intra-articular results. The correlation between these two assessment methods and clinical outcomes remains unclear. Purpose: To evaluate the correlation between MRI findings assessed using the MOCART scoring system and functional outcomes, as well as arthroscopic second look, in patients undergoing (AOT) for osteochondral lesions of the talus. Methods: A retrospective analysis was conducted on 47 patients. All patients were followed for a minimum of two years postoperatively. Functional evaluations were performed at one and two years after surgery using the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Visual Analog Scale (VAS). Imaging assessments utilized the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system. All patients underwent secondary arthroscopy for internal fixation removal at the two-year mark, during which the International Cartilage Repair Society (ICRS) scores were recorded. Results: There was a low correlation between the MOCART scores and both functional scores and arthroscopic scores postoperatively. At one year post-surgery, the MOCART score showed a low correlation with the AOFAS score (r=0.27, p=0.07, 95% CI: -0.01 to 0.36). By two years post-surgery, the MOCART score demonstrated a low correlation with the AOFAS score (r=0.34, p=0.02, 95% CI: 0.05 to 0.49), VAS score (r=-0.46, p<0.05, 95% CI: -0.08 to -0.02), and ICRS score (r=0.36, p<0.05, 95% CI: 0.40 to 3.11). ICRS and AOFAS scores (r = 0.56, p < 0.05, 95% CI: 1.19 to 3.07), indicating a moderate correlation. Conclusion: In autologous osteochondral transplantation (AOT) for the talus, the MOCART scores showed a low correlation with clinical function or secondary arthroscopic scores. The MRI assessment of talar cartilage repair requires more detailed evaluation. Level of Evidence:4