A 26-year-old man lands on a plantarflexed foot during a jump and develops midfoot pain and swelling. Weight-bearing radiographs show a small bony avulsion fragment between the base of the second metatarsal and the medial cuneiform, with more than 2 mm of diastasis at that interval. The avulsed structure represented by this fleck sign is the:
- A Plantar fascia origin
- B Tibialis anterior insertion
- C Lisfranc ligament ✓
- D Deltoid ligament deep fibres
Correct answer: C. Lisfranc ligament
Explanation
The fleck sign is pathognomonic of a Lisfranc injury: the strong Lisfranc ligament running from the lateral aspect of the medial cuneiform to the base of the second metatarsal avulses a bony fragment. Diastasis greater than 2 mm confirms instability. The tibialis anterior inserts on the medial cuneiform and first metatarsal but is not the source of this specific fragment.
Reference: Rockwood and Green's Fractures in Adults, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.