Piia Kristiina Valonen1, Hertta Pulkkinen1, Virpi Tiitu1, Mikko Lammi1, Risto Ojala2, Miika Nieminen2, Ilkka Kiviranta3
1University of Kuopio, Kuopio, Finland; 2 Oulu University Hospital, Finland; 3University of Helsinki, Finland
T2-weighted imaging, T1-mapping, and dGEMRIC were used to follow spontaneous repair of osteochondral defect in rabbits. Lesions (∅ 4 mm, 3 mm in depth) were made into the patellar groove, and MRI was taken 1 week, 2, 4, and 6 months after surgery. Pre-contrast T1-values shortened significantly for cartilage and bone repair, with cartilage T1 approaching the value of intact tissue. The dGEMRIC index also showed a decreasing trend. MRI was successfully used to follow the properties of spontaneous repair tissue, but in six months it did not achieve the structure of intact cartilage, shown with MRI and histology.