Quantitative T2 mapping during follow-up after matrix-associated autologous chondrocyte transplantation (MACT): Full-thickness and zonal evaluation to visualize the maturation of cartilage repair tissue

The purpose of this article was to evaluate the potential of in vivo zonal T2‐mapping as a noninvasive tool in the longitudinal visualization of cartilage repair tissue maturation after matrix‐associated autologous chondrocyte transplantation (MACT). Fifteen patients were treated with MACT and evaluated cross‐sectionally, with a baseline MRI at a follow‐up of 19.7 ± 12.1 months after cartilage transplantation surgery of the knee. In the same 15 patients, 12 months later (31.7 ± 12.0 months after surgery), a longitudinal 1‐year follow‐up MRI was obtained. MRI was performed on a 3 Tesla MR scanner; morphological evaluation was performed using a double‐echo steady‐state sequence; T2 maps were calculated from a multiecho, spin‐echo sequence. Quantitative mean (full‐thickness) and zonal (deep and superficial) T2 values were calculated in the cartilage repair area and in control cartilage sites. A statistical analysis of variance was performed. Full‐tickness T2 values showed no significant difference between sites of healthy cartilage and cartilage repair tissue (p