• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.404-412
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• 2021

Purpose: This study examined the degree of cartilage regeneration by performing second-look arthroscopy in a group of patients who underwent high tibial osteotomy and microfractures for unicompartmental osteoarthritis of the medial knee joint and to determine the factors affecting cartilage regeneration. In addition, this study analyzed whether there is a relationship between the degree of cartilage regeneration and functional results. Materials and Methods: From 2007 to 2015, this study evaluated 81 cases who underwent second-look arthroscopy at the time of plate removal after a microfracture and high tibial osteotomy with a minimum two-year follow-up. The degree of femoral cartilage injury before surgery was classified by ICRS (International Cartilage Research Society), and all were grade III and IV. After second-look arthroscopy, cartilage regeneration was classified into a well-regenerated group (grade I, II) and a poorly regenerated group (grade III, IV). The independent factors influencing cartilage regeneration were identified through multivariate logistic regression analysis. In addition, the functional results were compared before and after surgery between the two groups using the Knee Society score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index score (WOMAC). Results: Age, sex, body mass index, postoperative radiologic factors, and preoperative joint condition did not affect the degree of cartilage regeneration significantly. The large cartilage defect (≥2.0 cm²) (p=0.011) and the presence of kissing lesions (p=0.027) were associated with poor cartilage regeneration. No significant difference in the KSS and WOMAC scores was observed between the group with good and poor cartilage regeneration. Conclusion: The presence of a large cartilage defect and kissing lesions is associated with poor cartilage regeneration after high tibial osteotomy and microfracture. On the other hand, the degree of the regenerated cartilage did not show any correlation with the functional outcome.