Presentation
Ankle twisting since one month with ankle pain swelling.
Patient Data
Conventional radiographs shows subchondral lucency of the lateral talar dome with adjacent sclerosis.
the lateral talar dome shows marrow edema signal with patchy area of low T1 and high PD fat suppression and STIR signal intensity as well as subchondral irregular hypointense fracture line. Associated marrow edema signal of the talus body and neck is seen as well
intact collateral ligaments of the ankle
intact tendo-Achilles
minimal tibio-talar joint effusion
a small lobulated 1.5 X 1 cm lesion is seen within the distal tibial metadiaphysis. It shows low T1 and high T2/GRE signal with intra-lesional focus of low signal in all pulse sequences
normal signal and girth of the peri-articular musculature with no soft tissue mass lesion
Case Discussion
lateral talar dome osteochondral lesion; consistent with stage III osteonecrosis of the talar dome with bone marrow edema and subchondral fracture
linimal tibio-talar joint effusion
distal tibial metadiaphysis benign-looking lesion likely small enchondroma or intra-medullary infarction