Review Note

Musculoskeletal: Foot and Ankle

Case: ankle inversion and dorsiflexion in a 31 y/o female. 

Plain film yellow arrow: subtle {{c1::lucency}} of the lateral talar dome

MR yellow arrow: linear fluid signal {{c3::intensity}} {{c2::subchondral}} lesion.

MR Red arrow: irregularity of the overlying {{c4::subchondral}} bone plate. 

Diagnosis: {{c5::Osteochondral lesion of the lateral talar dome}}

Osteochondral lesion of the lateral talar dome: Morti se radiograph (left image) shows a subtle lucency of the lateral talar dome (arrow). Coronal T2-weighted MRI with fat suppression shows a linear fluid signal intensity subchondral lesion (yellow arrow), with irregularity of the overlying subchondral bone plate (red arrow). The fluid undercutting the lesion indicates instability.