Graft maturation of autologous chondrocyte implantation: magnetic resonance investigation with T2 mapping.

Background:Autologous chondrocyte implantation (ACI) using tissue-engineered cartilage is a successful therapy for full-thickness cartilage lesions in the knee joint. However, in vivo graft maturation is still unclear.Purpose:The aim of this prospective study was to analyze graft maturation after ACI in the knee using objective T2 mapping in correlation with the clinical outcomes within a 3-year postoperative course.Study Design:Case series; Level of evidence, 4.Methods:A total of 13 patients with isolated cartilage defects of the knee were treated with Novocart 3D, a matrix-based ACI procedure in the knee joint. The patients had complete data from International Knee Documentation Committee (IKDC) scores and MRI examinations for 6 to 36 months postoperatively. All cartilage defects were arthroscopically classified as Outerbridge grades III and IV. The mean area of the cartilage defect was 5.6 cm2. Postoperative clinical and MRI examinations were conducted at 6, 12, 24, and 36 months after surgery. The mod...