Background: To date, few studies have been published reporting the 5-year follow-up of clinical and radiological outcomes for chondral defects treated with matrix-induced autologous chondrocyte implantation (MACI).
Hypothesis: A significant improvement in clinical and radiological outcomes after treatment of symptomatic, traumatic chondral defects of the knee with the MACI implant will be maintained up to 5 years after surgery.
Study design: Case series; Level of evidence, 4.
Methods: A prospective evaluation of the MACI procedure was performed in 21 patients with chondral defects of the knee. After the MACI procedure, patients were clinically assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS), the Tegner-Lysholm score, the International Knee Documentation Committee (IKDC) Subjective Knee Form, and the modified Cincinnati score at years 1, 2, and 5. The quality of repair tissue was assessed by magnetic resonance imaging using the magnetic resonance observation of cartilage repair tissue (MOCART) score at months 3 and 6 and years 1, 2, and 5.
Results: Significant improvements (P < .05) were observed for all 5 KOOS subcategories at year 1 and were maintained through year 5 in 90.5% of patients (19/21). Treatment failure occurred in only 9.5% of patients (2/21). Significant improvements (P < .05) from baseline to year 5 were also observed for the IKDC score (30.1 to 74.3), the modified Cincinnati score (38.1 to 79.6), and the Tegner-Lysholm activity score (1.8 to 4.3). Similarly, the MOCART score significantly improved (P < .001) from baseline to year 5 (52.9 to 75.8). After 5 years, complete filling (83%) and integration (82%) of the graft were seen in the majority of patients. Signs of subchondral bone edema were still present in 47% of patients at 5 years. No product-specific adverse events were reported over the 5-year follow-up period.
Conclusion: Patients treated with a MACI implant demonstrated significant clinical improvement and good quality repair tissue 5 years after surgery. The MACI procedure was shown to be a safe and effective treatment for symptomatic, traumatic chondral knee defects in this study.