Fig. 2

T1-weighted turbo spin echo sequences (T1-TSE) follow-up MR images in the sagittal plane of osteochondrosis dissecans of the left knee joint of twin 1 from (a) symptom onset, after (b) three months, (c) six months, (d) one year, (e) one and a half years to complete regression of the lesion after a little more than (f) two years. The cartilage surface remains intact at all times, the reactive cartilage thickening as well as the perifocal edema regress completely