OBJECTIVE. In this retrospective study, we describe the MR imaging patterns
of various causes of flexor hallucis longus tendon entrapment.
CONCLUSION. Entrapment of the flexor hallucis longus tendon may be due to a
n enlarged os trigonumtarsitarsi, calcaneal fracture, and soft-tissue scar.
These disorders have characteristic imaging findings that may be revealed
on MR imaging.