56yo male suffered a seizure in the bathroom 4 weeks ago (first known seizure, of unknown cause). Once regained consciousness, multiple abrasions and bruises noted, with painful weightbearing on left foot.
Widening of the lisfranc interval with lateral displacement of the 2nd metatarsal and mal-alignment of the 2nd metatarsal in relation to the intermediate cuneiform was noted.
Widening of the lisfranc interval
A Lisfranc injury is a fracture dislocation of the metatarsal bones from the tarsus and was originally described as an amputation line through the tarsometatarsal joints. Injury to this joint often results in significant loss of function and disability, often leading to surgical fixative management.
The Lisfranc ligament is a collagenous connection between the base of the 2nd metatarsal and the medial cuneiform; consisting of a dorsal, plantar and interosseous components. The interosseous component is the most clinically significant portion.
Scanning the midfoot revealed widening of the lisfranc joint with laxity upon manually stressing the joint (note: ultrasound can only accurately assess the dorsal capsular component of the lisfranc ligament).
Upon assessing the dorsal tarso-metatarsal joints, multiple capsulo-ligamentus avulsions are noted as often seen in this type of fracture dislocation injury.
This patient was referred for orthopaedic management.
Lisfranc joint widening with laxity on manual stressing
TMT joints in long axis. Note the multiple capsulo-ligamentus avulsions