Osteochondral lesion of the medial femoral condyle. The osteochondral fragment is not displaced and displays an iso-to-low signal on T1 and isosignal to the normal bone on PD fat sat with surrounding high signal line "rim sign" and subchondral oedema.
ACL, PCL, and collateral ligaments are intact. No meniscal tear is seen.
No significant joint effusion is seen.