75M 4 months lateral ankle and foot pain



The Sinus Tarsi Bursa (of Gruberi) is situated between the lateral talar neck and the EDL. In this case its distended by fluid and contains thick cords of fat signal (red arrows). Would you consider this lipoma arborescens of the sinus tarsi bursa, even though the fat signal doesnt appear to branch? The majority of these bursae are soft and compressible. There is, however, atrophy and edema of the EDB muscle (blue arrow), suggesting anterior tarsal tunnel syndrome. Do you think this bursa is causing compression of the deep peroneal nerve? Reference article.
bursa