Spheroid-based matrix-induced autologous chondrocyte implantation combined with autologous bone grafting restores physiological cartilage and subchondral bone properties in osteochondral knee defects-An MRI-based analysis

This study aimed to evaluate the radiological and patient-reported outcome measures (PROMs) following spheroid-based matrix-induced autologous chondrocyte implantation combined with autologous bone grafting (MABCI) for the treatment of osteochondral defects of the knee. In this retrospective cohort analysis of prospectively collected data, 28 consecutive patients with 29 defects of the femoral condyle (male: 15, female: 13, mean age 27.3&#x2009;&#xb1;&#x2009;9.8 years, mean defect size 3.7&#x2009;&#xb1;&#x2009;1.6&#x2009;cm&#xb2;) treated with MABCI were included. Radiological assessments were performed using 3T magnetic resonance imaging (MRI) to evaluate cartilage thickness, T2 relaxation times and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 scores. Clinical outcomes were assessed using validated PROMs, including the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Lysholm scale and the Patient-Reported Outcomes Measurement Information System 29-Item Profile (PROMIS-29). Correlation analyses were conducted to evaluate associations between radiological parameters and PROMs. The analysis was conducted at a mean follow-up of 44.4&#x2009;&#xb1;&#x2009;21.6 months. Cartilage thickness in the repair tissue exceeded that of the reference cartilage (3.4&#x2009;&#xb1;&#x2009;0.9&#x2009;mm vs. 3.0&#x2009;&#xb1;&#x2009;0.5&#x2009;mm; p&#x2009;=&#x2009;0.036), while T2 relaxation times in the repair tissue were within physiological range (50.5&#x2009;&#xb1;&#x2009;40.0&#x2009;ms vs. 41.3&#x2009;&#xb1;&#x2009;5.4&#x2009;ms; n.s.). The mean MOCART 2.0 score was 61.3&#x2009;&#xb1;&#x2009;13.0 (volume fill: 16.1&#x2009;&#xb1;&#x2009;3.7, integration with adjacent cartilage: 12.9&#x2009;&#xb1;&#x2009;3.3), reflecting satisfactory repair quality. All clinical scores showed significant improvement compared to the preoperative condition (IKDC: 70.6&#x2009;&#xb1;&#x2009;13.2 vs. 54.8&#x2009;&#xb1;&#x2009;17.5, p&#x2009;<&#x2009;0.001; KOOS: pain 78.7&#x2009;&#xb1;&#x2009;16.9 vs. 66.1&#x2009;&#xb1;&#x2009;18.6, p&#x2009;=&#x2009;0.002, symptoms 75.6&#x2009;&#xb1;&#x2009;&#x202f;16.0 vs. 65.8&#x2009;&#xb1;&#x2009;19.1, p&#x2009;=&#x2009;0.006, ADL 86.8&#x2009;&#xb1;&#x2009;14.0 vs. 77.6&#x2009;&#xb1;&#x2009;16.8, p&#x2009;=&#x2009;0.003, sport 63.0&#x2009;&#xb1;&#x2009;24.2 vs. 47.3&#x2009;&#xb1;&#x2009;26.9, p&#x2009;=&#x2009;0.009, quality of life (QoL) 51.0&#x2009;&#xb1;&#x2009;22.7 vs. 39.6&#x2009;&#xb1;&#x2009;17.5, p&#x2009;=&#x2009;0.014; numeric pain rating scale: 3.0&#x2009;&#xb1;&#x2009;2.2 vs. 5.2&#x2009;&#xb1;&#x2009;2.4, p&#x2009;<&#x2009;0.001). A greater cartilage thickness was associated with reduced pain intensity (r&#x2009;=&#x2009;-0.457, p&#x2009;=&#x2009;0.013) and improved QoL (r&#x2009;=&#x2009;0.429, p&#x2009;=&#x2009;0.020), indicating that better structural repair is associated with improved patient satisfaction. MABCI results in satisfactory cartilage regeneration and subchondral remodelling in addition to significant improvements in patient satisfaction and overall QoL. Level III.