MR imaging of postoperative talar dome lesions

The number of surgical interventions of osteochondral lesions in the talar dome is steadily increasing. The surgical treatment with microfracturing or autologous chondrocyte transplantation has shown good clinical outcome at the midterm follow-up. With the development of advanced MR methods that are relatively specific for ultrastructural components of articular cartilage, compositional or biochemical MR has become possible in addition to the standard morphological evaluation of repair tissue. These quantitative MR techniques allow a monitoring of repair tissue on a molecular level. Using these techniques, the maturation of repair tissue, in particular the glycosaminoglycan content responsible for the biomechanical properties and the organization and content of collagen fibers, can be quantified and compared with normal hyaline cartilage. In addition, the diffusion properties of the repair tissue can also be analyzed by specific MR sequences.