EM@3AM: Lisfranc Injury
- May 26th, 2018
- Alan John
Author: Alan John, MD (EM Resident Physician, UTSW / Parkland Memorial Hospital) // Edited by: Brit Long, MD (@long_brit, EM Attending Physician, San Antonio, TX) and Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital)
Welcome to EM@3AM, an emDOCs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.
A 33-year-old male comes in to the emergency department after a soccer game with right foot pain and swelling. He was playing soccer earlier that day when he twisted his foot while running, and an opponent landed on his downwardly flexed foot. He has been unable to bear weight on his right foot since the injury and has noticed increased pain and swelling to the area.
Vital Signs: BP 123/80, HR 102, T 98.9 Oral, RR 20, SpO2 99% on room air
Physical exam reveals a patient who is athletically built in exam chair in mild discomfort with right foot swelling and pain. Patient is unable to bear weight on right leg and right foot exam is notable for midfoot edema with plantar ecchymosis.
What is the diagnosis, and what are your next steps?
Answer: Lisfranc injury
- Background: Lisfranc injuries are a spectrum of injuries involving the tarsometatarsal (TMT) joints. Injuries can be solely ligamentous or associated with fractures. A high index of suspicion is needed to prevent progression of foot deformity, pain, and dysfunction.
- Epidemiology: These injuries are fairly uncommon and only occur in 0.1-0.4% of all fracture/dislocations.
- Cases are often underdiagnosed and missed, especially in the setting of polytrauma. In fact, the diagnosis is missed in 20% of cases with the first evaluation.
- Anatomy: The lisfranc ligament connects the medial cuneiform to the base second metatarsal.
- This ligament stabilizes the second metatarsal and maintains the midfoot arch. There are several classifications of lisfranc injuries, but all involve disruption of the tarsometatarsal joint complex.
From Dr. Katy Hanson and Hanson’s Anatomy:
- History and Exam: Injury can occur by direct or indirect injury. Direct injury can occur from trauma (MVC, direct trauma) or crush injury. Indirect injury can occur from axial load on a plantar-flexed foot with twisting, bending, or rotation of the foot (commonly seen in athletic injuries).
- Physical exam reveals midfoot edema, inability to bear weight, and plantar ecchymosis.
- Tenderness with palpation along the midfoot is common.
- The piano key test includes exacerbation of pain with dorsal and plantar flexion of each digit.
- A single limb heel raise will cause worsening pain when the patient stands on one leg and then goes up on tiptoes (increased stress/strain on the injured area).
- A stress test of the midfoot (stabilizing the heel and twisting foot) will cause pain.
- Differential Diagnosis: Injuries of the lower leg, hindfoot (talus, calcaneus), forefoot (fifth metatarsal), midfoot (navicular, cuboid, cuneiform), and ankle can present with similar findings. The constellation of history, physical exam findings, and high index of suspicion can help aid in diagnosis of lisfranc injury.
- Diagnostics: Obtain X-ray of foot. Patients often do not meet criteria for imaging based on the Ottawa foot/ankle rules.
- Injuries form a high energy mechanism are often more apparent on X-ray, while those from low energy mechanisms are typically more difficult to diagnose. These should be evaluated with weight-bearing films.
- Check for fractures, alignment of the tarsals and metatarsals, and dorsal or plantar displacement of a metatarsal on lateral views.
- Fleck sign is an avulsion fracture of the lisfranc ligament involving the second metatarsal base or medial cuneiform.
- Widening of >2 mm between the first and second metatarsal joint (or >1 mm when compared to the opposite foot) is unstable and an indication for surgery (orthopedic consultation).
- If X-ray is negative but the diagnosis is suspected, obtain a 30 degree oblique X-ray (eliminates metatarsal overlap) and weight-bearing stress views.
- If injury to the TMT complex is suspected and there is an absence of findings on X-ray, CT should be obtained. CT can also be utilized especially in the setting of high impact injury to assess for fracture.
- Neurovascular evaluation is required. Dorsalis pedis pulse should be obtained, as transection of this vessel may occur.
- Discuss with orthopedics, especially with fracture displacement, dislocation, compartment syndrome, or neurovascular injury.
- Immobilize all with posterior splint and place on non-weightbearing status with crutches.
- Stable injury: TMT ligament sprain without widening or loss of the medial arch height on weight-bearing x-ray. Treatment includes non-weight bearing cast for 6-8 weeks with gradual return to activity.
- Unstable injury: TMT ligament disruption resulting in fractures, loss of foot arch, dislocation, plantar/dorsal displacement of joint, or widening of >2 mm between the first and second metatarsal joint. Treatment includes surgical consultation for repair.
- Prognosis: Full recovery can occur with this injury; however, many individuals never return to their pre-injury state of health. Additionally, chronic midfoot arthritis and pain are common complications associated with this injury.
Anderson, RB, Hunt, KJ, & McCormick, JJ. Management of common sports-related injuries about the foot and ankle. 2010. J Am Acad Orthop Surg, 18(9): 546-56.
Caswell, F & Brown C. Identifying foot fractures and dislocations. 2014. Emerg Nurse, 22(6): 30-4.
Englanoff G et al. Lisfranc Fracture-Dislocation: A Frequently Missed Diagnosis in the Emergency Department. Ann Emerg Med 1995: 26 (2); 229-233.
Sherief, T et al. Lisfranc injury: How frequently does it get missed? And how can we improve? Injury: International Journal of the Care of the Injured 2007: 34; 856-860.
Wedmore, I. et al. Emergency Department Evaluation and Management of Foot and Ankle Pain. Emergency Medicine Clinics of North America May 2015: 33 (2); 371-372.