Lisfranc Fracture Dislocation 

The Lisfranc joint, which represents the articulation between the midfoot and forefoot, is composed of the 5 tarsometatarsal (TMT) joints. The Lisfranc ligament is attached to the lateral margin of the medial cuneiform and medial and plantar surface of second metatarsal (MT) base. This is the only ligamentous support between first and second ray at midfoot level. Lisfranc joint injuries are rare, complex, and often misdiagnosed or inadequately treated. Lisfranc injuries can vary from simple ligament sprains to complete disruption of the TMT joint. Lisfranc fracture dislocations and sprains carry a high risk of chronic secondary disability. Best outcomes for these injuries require prompt recognition and then anatomic reduction and stabilization.

Recent studies

Henning et al^[1] prospectively studied a group of 40 patients who were randomized to receive either primary open reduction and internal fixation (PORIF) or primary arthrodesis (PA) of the first, second, and third TMT joint combined with Kirschner wire fixation of the fourth and fifth TMT joints. At an average of 53 months postoperatively, 32 patients were interviewed by telephone. Using Short Form (SF)–36 and the Short Musculoskeletal Function Assessment (SMFA) scores, the authors found no significant differences in patient satisfaction between the 2 groups.

Because of planned hardware removal in the PORIF group, the reoperation rate in the PORIF group was significantly higher than in the PA group. The PA group did have different complications than the PORIF group, including a nonunion and a delayed union, both of which were treated nonoperatively. While this was a level one study, it was limited by sample size, a low rate of participation amongst eligible patients, and a 20% loss of patients to follow up.

Schepers et al^[2] performed a pedobarographic study that showed reduced contact time and reduced contact area of the forefoot in 26 patients relative to the uninvolved side. While these patients expressed good satisfaction with the procedure (PORIF), with SF-36 scores averaging 101, their functional scores were only fair, with a median American Orthopaedic Foot and Ankle Score (AOFAS) of 72 and a Visual Analog Scale (VAS) score of 7.

Several recent papers have addressed the use of suture button fixation in Lisfranc injuries with the hope of allowing some physiologic motion and to avoid putting screws across the articular cartilage of the first cuneiform and the second metatarsal. Ahmed et al^[3] did a cadaveric study that showed more displacement with suture button fixation of isolated Lisfranc ligament injuries in cadaver specimens, which was in contradistinction to the study by Panchbhavi et al,^[4] which showed equivalence. Brin et al^[5] reported satisfactory results in 5 recreational and professional athletes. Lundeen and Sara,^[6] Baravarian and Geffen,^[7] and Watson et al,^[8] also describe their anecdotal use of this technique.

Jacques Lisfranc de Saint-Martin (1790-1847), a field surgeon in Napoleon's army serving on the Russian front, described a new amputation technique across the 5 TMT joints — one that did not require any bony osteotomy — as a swift solution to forefoot gangrene secondary to frostbite. This anatomical landmark became known as the Lisfranc joint, a term that is used today in the description of a wide spectrum of traumatic injuries to the TMT area of the foot. However, Lisfranc did not actually describe the injury pattern well known by this eponym. A Lisfranc injury encompasses everything from a sprain to a complete disruption of normal anatomy through the TMT joints. This type of injury was later described in equestrian riders who got their foot caught in a stirrup when they fell from a horse.

The Lisfranc ligament is a solitary ligament that connects the first ray (first metatarsal-medial cuneiform articulation) to the middle and lateral columns of the foot. Injury to this ligament, even in isolation, will result in functional instability with loss of longitudinal and transverse arch.^[9] Lisfranc injuries are commonly undiagnosed and carry a high risk of chronic secondary disability. Early recognition and treatment of injuries to the Lisfranc ligament are important to preserve normal foot biomechanics and function. Injuries to the Lisfranc articulations frequently lead not only to arthritis but also to severe pain.

Frequency

Lisfranc injuries account for 0.2% of all fractures.^[10] Incidence of this uncommon injury is reported as approximately 1 per 55,000 persons per year. It can occur in all ages but is more common in the third decade and is more common in males.^[11] Subtle Lisfranc sprain and diastasis have become more commonly diagnosed in athletes.^{[12, 13]}

The 2 major causes of Lisfranc injuries are low-energy, sports-related injuries and high-energy motor vehicle and industrial accidents. In low-energy settings, TMT injuries are caused by a direct blow to the joint or by axial loading along the MT, either with medially or laterally directed rotational forces. In high-energy injuries, the method of loading is not significantly different, but the energy absorbed by the articulations results in significantly more collateral damage to bony and soft-tissue structures, creating such injuries as MT fractures, cuneiform instabilities, and cuboid fractures.

The damage to the tight, ligamentous structures of this joint complex creates an unstable foot for weight bearing. The sense of instability and pain can occur whether or not overt evidence of instability is present. Chronic sprains resulting from relatively minor trauma can be the most debilitating sprains due to pain with weight bearing.

In diabetic patients with neuropathy or those with idiopathic insensate feet, subacute diastasis can occur over time without notable pain. Due to the absence of pain, this gradual process occurs, so that a minor injury can lead to a Lisfranc injury. In the authors’ opinion, the hallmark of an impending Lisfranc injury is the loss of the recess of the second MT base with the cuneiform, also known as the keystone. Radiographs are considered abnormal when weight-bearing anteroposterior (AP) views of the foot show the first TMT joint to be at the same level as the second TMT joint, indicating proximal migration of the first ray (see image below).

Patients with Lisfranc injuries can present with obvious anatomic deformities or with variable amounts of pain with weight bearing. Lisfranc injury should be excluded in any patient with midfoot pain on either the dorsal or the plantar aspect of the foot during weight bearing.

Clinical signs of Lisfranc injury are the following:

• Swelling out of proportion with a normal radiograph
• Plantar midfoot ecchymosis (see image below)Clinical identification of typical plantar ecchymosis pattern observed in Lisfranc injuries.
• Pain along the TMT joints with palpation, motion, and/or weight bearing
• Midfoot instability

All suspected injuries require a careful workup. Even significant injuries can reduce spontaneously, thereby hiding the initial deformity. The exaggerated swelling is the key in the differential diagnosis of subtle injuries. Special attention should be paid to patients with decreased sensation in the feet, such as diabetics, because they may be more at risk for progressive neuropathic changes. Likewise, trauma patients who are non–weightbearing because of other injuries should be carefully screened and examined in the presence of midfoot pain and/or characteristic ecchymosis.

Athletes

Lisfranc injuries are seen more commonly in football players, gymnasts, ballet dancers, and track-and-field athletes. Lisfranc injury in a professional hockey player has also been reported.^[14] The Lisfranc injury can potentially be a career-ending injury, particularly in elite gymnasts, as noted by Chilvers and colleagues.^[15] The mechanism of injury for most athletes is axial loading on a hyperplantarflexed midfoot. For ballet dancers, the pointe shoe design has been shown to stabilize the Lisfranc joint while in the en pointe position.^[16]

Lisfranc injuries in athletes have been classified according to the American Medical Association’s Standard Nomenclature of Athletic Injuries. First- and second-degree sprains have been classified as partial ligament tears with swelling, focal pain, no instability, and normal radiographs. Instability and diastasis between the first and second MT of greater than 2 mm as seen on AP radiographs is consistent with a third-degree sprain.^{[12, 13]}

Patients with undisplaced injuries are treated conservatively. Patients with displaced Lisfranc injuries should undergo closed or open reduction. All Lisfranc injuries that cannot be reduced and be made to remain stable by closed means should undergo internal fixation. An absolute indication for open reduction is vascular compromise that does not improve with closed reduction.^[10]

Successful closed reduction of displaced Lisfranc dislocations is quite rare. Closed treatment of displaced Lisfranc injuries should probably be reserved for patients who have sustained catastrophic spinal cord injuries and are not expected to walk again.

The Lisfranc joint is composed of 5 TMT joints in which the first through third MTs articulate with their corresponding medial, middle, and lateral cuneiforms. The fourth and fifth MTs articulate with the cuboid. The Lisfranc joint can be functionally divided longitudinally into the first ray, or medial column; the middle column, consisting of the second and third TMT joints; and the lateral column, consisting of the fourth and fifth TMT joints. A transverse line through these joints is not straight but highlights a recess, termed the keystone (similar to a Roman arch), formed by the second TMT joint. This joint lies approximately 1 cm proximal to the first TMT joint line and 0.5 cm proximal to the third TMT joint line.

The joints are bound by thick plantar ligaments that form an interlocking pattern between the tarsal and lesser MT bones 2-5. These are reinforced by attachments of the posterior tibialis tendon. The first TMT joint also has strong plantar ligaments across the joint; these are reinforced by the attachment of the peroneus longus and anterior tibialis tendons. Also present between the lesser MTs is a series of intermetatarsal ligaments, which force the group to function more as a unit. No intermetatarsal ligaments exist between the first and second MTs, which is why they often exhibit divergent behavior. The weaker dorsal ligaments explain the majority of dorsal dislocations.^[17]

The Lisfranc ligament originates from the plantar lateral aspect of the medial cuneiform and attaches to the plantar medial aspect of the second MT base. It is the thickest of the ligaments in this region, measuring up to 1 cm wide. This ligament provides the only soft-tissue link between the medial ray and the lesser MT and is responsible for this area's stability.

Motion at the TMT joints is variable. The second and third joints are the stiffest, with minimal motion in the dorsal/plantar plane and none in the medial or lateral plane. The third and first TMTs exhibit progressively more motion in both planes but still are relatively stiff and mainly function as areas of adjustment to allow the MT heads to share weight equally. The lateral 2 TMT joints demonstrate roughly 3 times more motion in the dorsal or plantar plane than does the first TMT joint. That motion is significant in the function of the foot and must be preserved to maintain normal function, especially if stiffness occurs in the medial and middle columns.

In the column theory, the middle column is more important for rigidity, and the medial and lateral columns are more important for shock absorption during gait. The lateral joints are more important for their mobile contributions to the balancing of forefoot weight bearing. This principle is important in treating these injuries.

Anatomic alignment is important for stable function, but the risk of infection and soft-tissue compromise may preclude surgery until the tissues stabilize. Patients with open injuries or vascular compromise should be approached carefully. A delayed fusion of the medial 3 TMT joints can be performed if pain persists with weight bearing.