5 Minute Assessment Assistant: Picking up low-energy Lisfranc injuries
Background: A Lisfranc injury is a sprain, fracture, or dislocation of the midfoot, most often of the 2nd tarsometatarsal (TMT) joint. Up to 20% of low energy Lisfranc injuries are missed on assessment, leading to progressive deformity, post-traumatic arthritis, and decreased function.
Mechanism: Lisfranc injuries are caused by direct trauma or indirect (low energy) trauma. Direct trauma injuries involve a crushing mechanism, where low energy injuries are caused by supination/pronation in a plantarflexed foot.
Assessment: Clinical findings are more obvious in direct trauma presentations, often with a deformity, swelling, pain, and inability to bear weight. In low energy injuries, there is often no deformity and the patient will likely be able to bear weight, even in the presence of swelling and pain. Here’s what you’re looking for…
Imaging: NWB radiographs can miss up to 50% of low energy injuries. It is suggested that bilateral WB radiographs can better detect a diastasis between the first and second metatarsals in more subtle injuries. MRI has a 94% predictive value of predicting Lisfranc joint instability.
Management: Stable/un-displaced injuries can be managed successfully with a 6 week NWB period, followed by gradual rehabilitation and return to activity. Orthopaedic opinion is necessary serious ligamentous disruption and instability are present. Delays in management are associated with worse functional outcomes.
Bottom Line: Low energy Lisfranc injuries are often missed on assessment. Delays in management are linked with worse functional outcomes and disability. Subjective and objective findings can lead you to a high clinical suspicion of a low energy Lisfranc injury. Stable injuries can be well managed with a period of NWB followed by progressive rehabilitation.
Welck M., .Zinchenko R., Rudge B. (2015). Lisfranc injuries. Injury 46(4), 536-541. https://doi.org/10.1016/j.injury.2014.11.026