Good reintegration of unstable osteochondritis dissecans at the femoral condyle following screw fixation: A 3-year magnetic resonance imaging and clinical follow-up study.

Purpose: Osteochondritis dissecans (OD) is characterized by detachment of osteochondral fragment. Surgical refixation is recommended in unstable lesions. The aim of present study was to analyse the reintegration of the cartilage after screw fixation of unstable OD in the knee using magnetic resonance imaging (MRI). Methods: A total of 16 cases were retrospectively included in the present study. At a minimum follow-up of 1 year, MRI was performed, and the cartilage quality was quantified using the Morphological Cartilage Assessment and Reporting Tool (MOCART). Clinical outcomes were evaluated at the same time point as the MRI assessment using the visual analog scale (VAS), the subjective knee evaluation form of the International Knee Documentation Committee (IKDC), the Knee Osteoarthritis Outcome Score (KOOS) and the return to sports (RTS) rate. Results: The average age was 18.6 ± 7.4 years. Thirteen lesions (81.2%) were located on the medial femoral condyle, while three lesions (18.7%) were found on the lateral femoral condyle. At a mean follow-up of 47.5 ± 24.6 months, evaluation of the MRIs showed an average MOCART score of 64.4 ± 17.8 indicating good cartilage condition. The mean IKDC score was 80.1 ± 14.9, the median VAS for pain was 0 (interquartile range 0-3), and the mean results of the KOOS were as follows: KOOS symptoms 84.6 ± 12.7, KOOS pain 87.7 ± 10.7, KOOS activities of daily living 95.6 (91.8-98.9), KOOS sport and recreation function 85.0 (60.0-90.0) and KOOS knee-related quality of life 75.0 (60.9-81.3). All the patients were able to RTS activities postoperation. Conclusion: Surgical screw refixation of unstable OD at the femoral condyles yielded good cartilage integration in MRI follow-up and excellent clinical outcomes as well as high RTS rates at a mid-term follow-up. Level of Evidence: Level II.