Aim: To investigate 10-year clinical and radiological outcomes in patients following matrix-induced autologous chondrocyte implantation (MACI) and compare outcomes in patients undergoing tibiofemoral (TF) versus patellofemoral (PF) MACI.
Methods: Between September 2002 and December 2012, 204 patients that underwent MACI were prospectively recruited and assessed pre-surgery and at 2, 5 and 10 years. Of these, 168 patients were available for clinical review at 10 years, of which 151 (of a total of 182) grafts were also assessed via magnetic resonance imaging (MRI). Patients were evaluated with patient-reported outcome measures (PROMs) including the Knee Injury and Osteoarthritis Outcome Score (KOOS), satisfaction and peak isokinetic knee extensor and flexor strength. Limb symmetry indices (LSIs) were calculated for strength measures. Grafts were scored on MRI via the magnetic resonance observation of cartilage repair tissue (MOCART) system, with a focus on tissue infill and an overall MRI graft composite score.
Results: All PROMs improved (p<0.0001) to 2 years post-surgery. Apart from the significant increase (p=0.004) in the peak isokinetic knee extensor LSI, no other PROM or clinical score had changed significantly from 2 to 10 years. At 10-year follow-up, 92% of patients were satisfied with MACI to provide knee pain relief, with 76% satisfied with their ability to participate in sports. From 2 to 10 years, no significant change was seen for any MRI-based MOCART variable, nor the overall MRI composite score. Of the 151 grafts reviewed via MRI at 10 years, 14 (9.3%) had failed, defined by graft de-lamination or no graft tissue on MRI. Furthermore, of the 36 patients (out of the prospectively recruited 204) that were not available for longer-term review, 7 had already proceeded to total knee arthroplasty and 1 patient had undergone secondary MACI at the same MFC site due to earlier graft failure. Therefore, a total of 22 patients (10.8%) had essentially failed over the period. At final follow-up, patients that underwent MACI in the TF (versus PF) joint reported significantly better KOOS sub-scale scores for Quality of Life (p=0.010) and Sport (p<0.001), as well as a greater knee extensor strength LSI (p=0.002). While the TF group demonstrated better 10-year MOCART scores for tissue infill (p=0.027), there were no other MRI-based differences (p>0.05).
Conclusion: This study reports the long-term review of a prospective series of patients undergoing MACI, demonstrating good clinical scores, high levels of patient satisfaction and graft survivorship 10 years. Patients undergoing TF (versus PF) MACI reported better long-term clinical outcomes, despite largely similar MRI-based outcomes.
