Evaluating single-stage cartilage treatments in the knee: A systematic review and meta-analysis of osteochondral autograft transfer surgery (OATS) and minced cartilage repair (MCR) techniques.

Abstract

Focal chondral lesions of the knee remain challenging to treat. Although small defects may respond to conservative management, moderate-sized lesions often require surgical intervention. Single-stage cartilage restoration procedures-osteochondral autograft transfer (OATS) and minced cartilage repair (MCR)-are gaining popularity due to lower morbidity, faster rehabilitation, and reduced cost compared with two-stage techniques. However, comparative evidence between these options is limited. This systematic review evaluates current literature and compares clinical and radiologic outcomes of OATS and MCR. Following PRISMA guidelines, studies were included if they reported clinical outcomes of OATS or MCR for moderate-sized chondral knee lesions, enrolled ≥10 patients, and had ≥12 months of follow-up. Clinical outcomes were extracted using International Knee Documentation Committee (IKDC) and Visual Analog Scale (VAS) scores, and radiologic outcomes using Magnetic Resonance Imaging Score and Classification System (MOCART) scoring. 19 studies (14 OATS, 5 MCR) comprising 736 patients (OATS n = 524; MCR n = 212) met inclusion criteria. No direct comparative trials were identified. Patients undergoing OATS (mean age 38.7 ± 12.8 years) demonstrated greater improvements in IKDC (40.49) and VAS scores (-4.27) than those treated with MCR (mean age 31.7 ± 6.8 years; IKDC 30.9; VAS -3.7). Mean defect sizes were similar (OATS 3.36 ± 1.80 cm²; MCR 3.39 ± 0.72 cm²). Twelve-month MOCART scores were comparable between groups (OATS 62.7; MCR 65). Longer follow-up in OATS studies (54.2 vs 32.9 months) may partially account for superior clinical outcomes. Both OATS and MCR yield favourable results for focal chondral knee lesions. Current evidence suggests greater clinical improvement with OATS, although radiologic findings appear similar in the short term. High-quality, long-term comparative studies are needed to clarify the relative durability and efficacy of these single-stage techniques.