Autologous collagen-induced chondrogenesis versus mesenchymal stem cell therapy combined with high tibial osteotomy for medial knee osteoarthritis: a retrospective study

BACKGROUND: Cartilage restoration techniques combined with high tibial osteotomy (HTO) have increasingly been used to delay conversion to total knee arthroplasty. Among these, autologous collagen-induced chondrogenesis (ACIC) and mesenchymal stem cell (MSC) therapy have gained significant research attention; however, their comparative therapeutic efficacy remains unclear. METHODS: A retrospective analysis was conducted on 102 patients with medial compartment knee osteoarthritis who underwent HTO combined with cartilage repair (ACIC, n = 70; MSC, n = 32). Arthroscopic and radiographic parameters, including International Cartilage Repair Society (ICRS) grade, cartilage defect size, Kellgren-Lawrence (KL) grade, and mechanical alignment, were evaluated preoperatively and at second-look arthroscopy performed during hardware removal (mean, 27.2 ± 12.2 months). Clinical outcomes, including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS), and International Knee Documentation Committee Subjective Knee (IKDC) scores, were also assessed preoperatively and at the last clinical follow-up (mean, 58.11 ± 30.85 months). RESULTS: ICRS grade significantly improved, and cartilage defect size significantly decreased in both groups (all p < 0.001). KL grade also showed significant postoperative improvement in both groups (p < 0.001). No significant differences were observed between groups in ICRS grade (p = 1.000), cartilage defect size (p = 0.202), and KL grade (p = 0.529). Both groups showed significant clinical improvements in WOMAC, VAS, and IKDC scores (all p < 0.001). There were no significant differences between the two groups in clinical outcomes (WOMAC, p = 0.430; VAS, p = 0.307; IKDC, p = 0.823). CONCLUSIONS: Both ACIC and MSC combined with HTO resulted in significant arthroscopic, radiographic, and clinical improvements in patients with varus knee osteoarthritis. No significant differences were observed, indicating comparable effectiveness of the two techniques when performed in conjunction with HTO.