A 26-year-old man sustains a midfoot injury when another player falls on his plantar-flexed foot. Radiographs show a small bony avulsion fragment between the medial cuneiform and the base of the second metatarsal, with more than 2 mm diastasis at that interval. This 'fleck sign' indicates injury to which structure?
- A Deltoid ligament
- B Lisfranc ligament ✓
- C Bifurcate ligament
- D Spring ligament
Correct answer: B. Lisfranc ligament
Explanation
The fleck sign is an avulsion fracture at the attachment of the Lisfranc ligament, which runs from the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. It is pathognomonic of a Lisfranc (tarsometatarsal) joint disruption. Diastasis greater than 2 mm at the medial cuneiform to second metatarsal interval confirms instability. The bifurcate and spring ligaments are midfoot stabilisers but do not produce this avulsion pattern.
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.