The aim was to use repeat delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) to estimate glycosaminoglycan (GAG) content in reparative cartilage after osteochondral autogenous transfer (OAT). The study group comprised 7 knees of 7 patients that were examined three times by dGEMRIC, at 3, 6, and 12 months using a 1.5 Tesla MRI system in both OAT operated and nonoperated condyles at 90 min after the injection. The gadolinium diethylene triamine pentaacetic acid (Gd-DTPA)2- containing contrast medium (0.2 mmols/kg) was injected intravenously. The mean T1 values of the plug cartilage at 3, 6, and 12 months after OAT was 230 +/- 40, 213 +/- 31, and 230 +/- 23 ms (mean +/- SD), respectively. There were differences between the plug and control cartilage at 3 (p<0.01) and 12 (p<0.05) months after OAT, but not at 6 months (p=0.089). No T1 changes were detected between the plug cartilage at the different time points after OAT. The fact that the GAG content of the OAT plugs were maintained for 12-month study period suggest that no major deterioration of load-bearing properties occurs in the cartilage after the OAT. (C) 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:221225, 2012