Autologous bone grafting combined with spheroid-based matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: Good clinical outcomes alongside abnormal postoperative gait patterns.

Abstract

Purpose: This study aimed to evaluate the clinical and functional outcomes of autologous bone grafting with spheroid-based matrix-induced autologous chondrocyte implantation (MABCI) for osteochondral defects of the knee by analysing pre- and postoperative patient-reported outcome measures (PROMs). Postoperative gait analysis was conducted and compared with a matched healthy control group to investigate biomechanical deviations.

Methods: A total of 35 patients (m: 21, f: 14; mean defect size: 4.2 ± 2.4 cm², localisation: femoral condyle: 31, patellofemoral: 5) were analysed. The mean follow-up was 42.6 ± 22.8 months. International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), PROMIS 29 profile, and a questionnaire on patient perception of treatment success were assessed to evaluate PROMs. 3D-instrumented gait analysis (GRAIL, Motek) was used to assess lower extremity kinematics, kinetics and vertical ground reaction forces, compared to sex-, age- and body mass index-matched healthy controls.

Results: All clinical scores showed significant improvement compared to the preoperative condition (IKDC: 73.1 ± 10.1 vs. 56.6 ± 17.2, p < 0.01; KOOS subcategories: pain 82.0 [±12.7] vs. 70.7 [±16.7] [p < 0.01], symptoms 79.1 [±20.3] vs. 68.9 [±13.9] [p < 0.01], activities of daily living 90.1 [±11.2] vs. 80.5 [±15.6] [p < 0.01], sport and recreational function: 65.3 [±19.3] vs. 51.3 [±26.29] [p < 0.01], quality of life 52.2 [±18.6] vs. 42.6 [±18.6] [p < 0.01]; numeric pain rating scale: 2.7 ± 2.0 vs. 5.0 ± 2.5, p < 0.01). The analysed patients reported a high satisfaction rate (94.3%). Self-selected walking speed was significantly lower than in healthy controls (1.17 ± 0.17 m/s vs. 0.98 ± 0.18 m/s, p < 0.01). Peak knee flexion angle (PKA) during loading response was significantly smaller (9.6° ± 7.0 vs. 17.7° ± 4.6, p < 0.01), and knee extension moment was significantly reduced (0.1 Nm/kg ± 0.2 vs. 0.4 Nm/kg ± 0.2, p < 0.01).

Conclusion: MABCI is an effective treatment for osteochondral knee defects, showing significant improvements in all evaluated PROMs. Postoperative gait analysis revealed abnormal gait patterns, including reduced PKA and lower knee extension moment, suggesting a need for further rehabilitation to optimise functional recovery.

Level of evidence: Level III.