Lisfranc Injury

Lisfranc Injury

Lisfranc injury is an important topic. If Lisfranc injury is not diagnosed and treated properly, it can lead to an altered gait, midfoot arthritis, and long term disability. Lisfranc injury indicated disruption between the base of the 2^nd metatarsal and the medial cuneiform. Lisfranc injuries are a spectrum of injuries of the tarsometatarsal joints. Diagnosing Lisfranc injury is important. Diagnosis is missed in about 20%-30% of cases especially in multiple trauma patients. A high index suspicion is needed to prevent progression of the foot deformity, chronic pain, and dysfunction. You may need weight-bearing films for diagnosis of Lisfranc injury. Lisfranc injury may also be associated with compartment syndrome. Lisfranc injury could be purely ligamentous or can be associated with fractures. ORIF is better in cases of fractures. Arthrodesis is better in cases of purely ligamentous injury. In general, ligamentous injury does worse than fractures. The Lisfranc ligament is a large oblique ligament that extends from the plantar aspect of the medial cuneiform to the base of the second metatarsal. The Lisfranc ligament stabilizes the 2^nd metatarsal and maintains the midfoot arch. Osseous stability is provided by the roman arch of the metatarsals and the recessed keystone of the 2^nd metatarsal base. Tarsometatarsal joint complex is divided into three units: medial, middle, and lateral. The medial is the 1^st metatarsal joint at 6^o mobility. The middle is the 2^nd and 3^rd tarsometatarsal joints, and it is rigid. The lateral is the 4^th and 5^th tarsometatarsal joints; it is mobile which is why you do not fuse the 4^th and 5^th tarsometatarsal joints. The dorsalis pedis artery and the deep peroneal nerve both run between the first and second metatarsal bases. A direct injury with a plantar displacement is more common. Indirect injuries are more common than direct injuries. They result from axial loading or twisting on a plantar flexed midfoot. Dorsal displacement of the 2^nd metatarsal is more common. Check the alignment of the dorsum of the 2^nd metatarsal with the middle cuneiform. Associated fractures are typically tarsal fractures, especially a cuboid fracture. A “Nutcracker” fracture results from twisting injury causing forceful abduction of the forefoot. It is a fracture of the base of the 2^nd metatarsal and compression fracture of the cuboid. ^nd metatarsal, at the navicular, and cuboid. Check for widening between the first and second ray (more than 2 mm is an indication for surgery). In the lateral view, check the dorsal displacement or subluxation of a metatarsal. It should be at the level of the corresponding cuneiform. Check for the FLECK sign (bony fragment). Avulsion fragment of the Lisfranc ligament from the base of the 2^nd metatarsal. The medial side of the fourth metatarsal should line up with the medial side of the cuboid on the oblique view (30^o). CT scan can be useful and MRI can confirm purely ligamentous injury. These injuries should be treated with a cast. For a dorsal sprain and no instability, the patient can be treated with non-weight bearing cast for 6 weeks and return to activity gradually. Surgery can be done for instability. Open reduction internal fixation with cortical screws if there is bony fractures. When you do ORIF- you need anatomic reduction. Hardware removal between 5-6 months (some surgeons leave the hardware in place indefinitely). Arthrodesis if the injury is purely ligamentous. Healing of the ligaments is less reliable than bony healing. Purely ligamentous injury needs primary arthrodesis. Arthrodesis is also done in old injuries if there is delay in treatment for if there is failure of open reduction and internal fixation of Lisfranc injury. Midfoot arthrodesis is also used for chronic Lisfranc injury that leads to severe midfoot arthritis with progressive arch collapse and midfoot abduction. Fusion of the medial and middle column; first, second, and third tarsometatarsal joints. Do not fuse the lateral column (lateral column is mobile). For the lateral column, do reduction and stabilization by k-wire fixation. Post-traumatic arthritis occurs in up to 50% of patients. Patient may have altered gait and long term disability. Purely ligamentous injury has a worse prognosis than injuries with fractures. Malalignment of the fractures usually lead to arthritis.

Lisfranc classifications are not useful in deciding the treatment or the prognosis of the injury. Severe injuries are obvious, easily diagnosed, and may develop compartment syndrome of the foot. Injuries with minimal displacement could be missed, and they will need surgery regardless of the classification. Arthritis may develop even with minimal displacement. In general, there are three patterns of injury: total incongruity, partial incongruity, and divergent. Total incongruity occurs when all five metatarsals are displaced in the same direction. Total incongruity occurs lateral or medial, with lateral being more common. Partial incongruity occurs when one or two metatarsals are displaced from the others. Divergent occurs when the lateral displacement of the lesser metatarsals with medial displacement of the first metatarsal. The one thing all these injuries have in common is disruption of the tarsometatarsal joint complex. The patient has severe pain in the midfoot and is unable to bear weight. There may be some swelling in the midfoot dorsally. Plantar bruising may be present, especially medially. Tenderness over the tarsometatarsal joint. Check the skin condition and rule out compartment syndrome. Check the neurovascular status of the foot. Plantar ecchymosis is a classic clinical sign of potential Lisfranc injury. Wight bearing standing x-rays with comparison views if x-rays are normal and if the physician clinically suspects a Lisfranc injury. Another alternative is to get physician assisted midfoot stress radiograph. Obtain three views: AP, oblique, and lateral. Medial border of the second metatarsal should line up with the medial border of the middle cuneiform on both the AP and the oblique view. Check for fractures, especially at the base of the 2