Board Review: Orthopedics
A 18M restrained driver is involved in a head-on motor vehicle collision. He complains of right foot pain. The XR is below. What is the diagnosis?
A. Lisfranc Fracture
B. Jones Fracture
C. Pseudo-Jones Fracture
D. Multiple Metatarsal Fractures
Answer: A - Lisfranc Fracture
-The Lisfranc joint complex is tarsometatarsal articulation of 1st, 2nd, and 3rd metatarsals with the medial, intermediate and lateral cuneiforms, respectively, as well as articulation of 4th and 5th metatarsals with the cuboid.
-The Lisfranc ligament secures the second metatarsal to medial cuneiform.
-Mechanism: axial load to plantar-flexed foot -20% are missed on first evaluation and physical exam findings may be subtle so it should be part of the differential diagnosis of any midfoot trauma.
-if have high clinical suspicion but normal foot X-Rays, do not rule out Lisfranc fracture; can do weight bearing plain films or CT scan.
Subtle XR Findings:
-avulsion fracture called “fleck sign”.
-diastasis (separation) of space between bases of 1st and 2nd metatarsals.
-a metatarsal shaft should never be more dorsal than its respective tarsal bone.
-NV exam with special attention to dorsalis pedis pulse.
-posterior splint immobilization and strict non-weight bearing status.