One-Year Clinical and Radiological Results of a Prospective, Investigator-Initiated Trial Examining a Novel, Purely Autologous 3-Dimensional Autologous Chondrocyte Transplantation Product in the Knee

BACKGROUND: The 3-dimensional autologous chondrocyte transplantation (ACT3D) comprises isolation of chondrocytes from cartilage biopsies, cultivation to spheroids, and transplantation into the cartilage defect. OBJECTIVES: To evaluate the patients’ general health and functionality and to assess the defect repair after ACT3D with spheroids by MRI and MOCART scoring. METHODS: Thirty-seven patients with isolated chondral lesions of the knee underwent ACT3D with spheroids through medial arthrotomy. Patient-administered scores were assessed at baseline (day before transplantation), at 6 weeks, and at 3, 6, and 12 months. MRI and MOCART scoring were performed at 3 and 12 months after ACT3D. RESULTS: Patients were diagnosed with full-thickness patellofemoral (n = 16), femoral condylar (n = 18), or both defect types (n = 3), International Cartilage Repair Society (ICRS) grade 3 or 4, with defect sizes between 1.0 and 12.0 cm(2). On average, 59.5 spheroids/cm(2) in defect size were transplanted. An overall statistically significant improvement from baseline to 12 months was observed for all assessment scores (Lysholm, International Knee Documentation Committee [IKDC], SF-36, Tegner) combined with a significant reduction in the visual analog scale (VAS) for pain and an advanced defect filling. Subgroup analyses revealed a positive clinical outcome independent on defect size, defect locations, spheroid dosage, age, duration of symptoms, and severity of complaints at baseline. Seven patients experienced in total 8 adverse events, of which knee joint effusion and blocking were assessed as possibly or probably related to ACT3D. CONCLUSIONS: The patient-administered assessment scores along with the fast defect filling with ACT3D using spheroids demonstrated an increase in activity level and quality of life after a 1-year follow-up.