Male 44 years old Reason: ankle pain, swelling History: swelling. We have 3 views of the left ankle which show an ossicle posterior to the talus. Relatively little edema in the pre-Achilles fat suggests this is a normal variant os trigonum, however, CT/MRI is recommended if there is strong clinical concern for fracture. Mild osteoarthritis affects the ankle joint and there is mild soft tissue swelling.We have 3 views of the left foot which show the aforementioned ankle findings and possibly a small tibiotalar joint effusion.
Ossicle posterior to talus is favored to represent a normal variant os trigonum. However, if there is strong clinical concern for fracture, CT or MRI may be considered.