Tarsometatarsal (Lisfranc) joint complex injuries

INTRODUCTION — Injuries to the tarsometatarsal (TMT) joint complex, commonly referred to as the "Lisfranc joint," are not common, but they are frequently missed and often lead to osteoarthritis and long-term disability. The risk of such adverse outcomes increases substantially when TMT joint complex injuries are diagnosed late and managed improperly. The Lisfranc joint is named for Jacques L Lisfranc, a French gynecologist and Napoleonic surgeon. Lisfranc described an amputation through the TMT joint line in a soldier who had suffered a midfoot injury during a fall from his horse [1].

The presentation, diagnosis, and management of TMT joint complex injuries is reviewed here. Other common foot injuries and fractures are discussed separately. (See "Overview of foot anatomy and biomechanics and assessment of foot pain in adults" and "Metatarsal shaft fractures" and "Proximal fifth metatarsal fractures" and "Stress fractures of the tarsal (foot) navicular" and "Cuboid and cuneiform fractures".)

EPIDEMIOLOGY — Acute injuries to the tarsometatarsal (TMT) joint complex comprise approximately 0.1 to 0.4 percent of all fractures and dislocations [2]. Unfortunately, nearly 20 percent of these injuries are missed or misdiagnosed on initial assessment [3]. TMT joint complex injuries can occur from direct or indirect trauma that may occur in the setting of a motor vehicle collision, fall from a height, or field sports, such as American football.

CLINICAL ANATOMY — An understanding of midfoot anatomy is required for the assessment of tarsometatarsal (TMT) joint complex injuries and for determining which injuries require surgical referral. Osseous components of the TMT joint complex include the five metatarsals, the three cuneiforms, and the cuboid (figure 1 and figure 2). The bases of the first (associated with great toe) through third (associated with middle toe) metatarsals and their articulations with the cuneiform bones form the transverse (or "Roman") arch (figure 3) [4,5]. Within this arch, the second metatarsal acts as a keystone, forming articulations with the other five bones. If there is displacement between the second metatarsal and the middle cuneiform, associated displacement of the third through fifth metatarsals is often present as well.

The so-called “Lisfranc ligament” consists of three distinct ligaments: the dorsal ligament, interosseus ligament, and plantar ligament (figure 4) [6,7]. Each of the three runs obliquely from the medial border of the second metatarsal to the lateral aspect of the medial cuneiform. The interosseus ligament is the strongest supporting structure of the TMT joint complex, capable of withstanding approximately twice the loads of the dorsal ligament [7]. It is traditionally but incorrectly referred to as the “the Lisfranc ligament.” The dorsal ligament is the weakest of the three (figure 5). The plantar ligament at the inferior aspect of the bones (figure 6) includes branches from the second and third metatarsals.

While transverse ligaments connect the second through fifth metatarsals, there is no transverse ligament attaching the first metatarsal to the second metatarsal. This contributes to the first metatarsal's propensity to displace when the TMT ligaments are injured (figure 7). In addition to osseous and ligamentous structural support, the TMT joint complex is strengthened by the short palmar muscles, peroneus longus, tibialis posterior and tibialis anterior muscles.

MECHANISM OF INJURY — Both indirect and direct forces can cause injury to the tarsometatarsal (TMT) joint complex. Crush injuries can create a variety of fracture and dislocation patterns.

Indirect injuries often result from an axial load placed on a plantar-flexed foot that then forcibly rotates, bends, or is compressed. One common mechanism involves an individual falling forward onto a plantar-flexed foot, such as after missing a step when descending a staircase. This mechanism also occurs in field sport athletes, such as when a player inadvertently steps on the heel of an opponent and the foot is forcibly plantar-flexed (picture 1 and figure 8). In rare instances, TMT injuries have occurred with simple acceleration during running.

Sports that require the use of a stirrup, including equestrian and windsurfing, can result in TMT injuries. The mechanism involves the forefoot being held in a fixed position in the stirrup while the athlete's body is thrown from the horse or board, resulting in severe rotation and bending of the midfoot. Motor vehicle collisions are another common mechanism seen with these types of injuries.

While TMT injuries are known to occur with high-energy trauma (eg, motor vehicle collision), a review from a level one trauma center reported that low-energy (eg, fall or twisting after a misstep) and sports-related trauma comprised over two-thirds of injuries during a one-year period [8]. Thus, clinicians should suspect Lisfranc injury in any patient presenting with midfoot pain, even in the setting of a low-energy mechanism.

HISTORY AND EXAMINATION FINDINGS — Patients with tarsometatarsal (TMT) joint complex injuries typically present with significant pain and swelling in the midfoot following acute trauma involving the mechanisms described above [9,10]. They are unlikely to be able to bear weight or stand on their toes with the affected foot. While often absent in isolated TMT sprains, plantar ecchymosis is often considered pathognomonic for significant TMT joint complex injuries (picture 2) [11,12].

The TMT joint complex spans the width of the foot and can involve several muscular and ligamentous injuries as well as fractures. Tenderness is common and may span a broad portion of the midfoot. Range-of-motion and strength testing may be limited due to pain. When such testing can be performed, plantar-flexion, dorsiflexion, and moving the first and second metatarsals divergently (eg, passively or actively moving these metatarsals in opposite directions—one is plantar-flexed while the other is dorsiflexed) generally elicit pain.

Special testing for TMT complex injuries may include a pronation-abduction test [13]. In this test, pain is elicited when the forefoot is abducted and pronated while the hindfoot is kept in place (picture 3). A tarsometatarsal squeeze test may also elicit pain. The tarsometatarsal squeeze or compression test is performed by placing a palm over the dorsum of the patient's midfoot, with the thumb placed broadly along the lateral midfoot and the other fingers placed along the medial midfoot. The examiner then applies compressive force, attempting to squeeze the first and fifth rays of the patient’s foot together (picture 4).

Neurovascular testing should include assessment of the dorsalis pedis pulse, as blood flow may be compromised by a dislocation of the second metatarsal [14]. Assessment for acute compartment syndrome of the foot is important if significant swelling and pain are present, and compartment pressure testing may be required. If compartment syndrome is suspected, immediate orthopedic consultation is required. (See "Acute compartment syndrome of the extremities".)

DIAGNOSTIC IMAGING

Plain radiographs — Anterior-posterior (AP), lateral, and oblique plain radiographs are the initial studies ordered in the assessment of midfoot injuries:

●AP radiograph – In the AP film, the medial border of the second metatarsal should be colinear with the medial border of the middle (intermediate) cuneiform (image 1).

●Oblique radiograph – In the oblique film, the medial border of the fourth metatarsal should be colinear with the medial border of the cuboid. Malalignment greater than one mm is considered pathologic (image 2 and image 3) [15].

The AP or oblique films may demonstrate an avulsion fracture at the origin or insertion of the Lisfranc ligament, which includes the medial cuneiform and the base of the second metatarsal. This finding, known as a "fleck-sign," is considered pathognomonic for a tarsometatarsal (TMT) joint complex injury (image 4) [16]. In addition, the presence of a proximal metatarsal fracture raises suspicion for a TMT joint complex injury (image 5).

●Lateral radiograph – On the lateral view, the dorsal and plantar borders of the metatarsals should align with the borders of the cuboid and cuneiform bones and any step-off is considered abnormal (image 6 and image 7). The presence of a second metatarsal base avulsion fracture or rupture of the plantar Lisfranc ligament are each predictive of TMT joint complex instability [17].

Weightbearing radiographs and advanced imaging — According to one small observational study, about half of athletes with midfoot injuries have normal non-weight-bearing radiographs [9]. Thus, if non-weight-bearing radiographs are normal, weight-bearing radiographs with body weight evenly distributed between both feet on a single cassette are required for proper first-line evaluation of midfoot injuries [10,18].

Nevertheless, multiple observational studies demonstrate that even properly performed, weight-bearing radiographs have limited sensitivity and specificity for detecting TMT injuries [19,20]. Therefore, in patients with a mechanism and examination findings consistent with an injury of the TMT complex, computed tomography (CT) or magnetic resonance imaging (MRI) should be obtained regardless of the absence of findings on plain radiographs [18]. MRI demonstrates high sensitivity and specificity for detecting injury to the Lisfranc ligament and provides valuable information about the stability of the TMT complex and the need for surgical referral (image 8) [17,21,22]. CT may be used to detect and delineate fracture patterns following high-energy injuries (image 9). If initial imaging is inconclusive but clinical suspicion for injury is high, another approach is dynamic fluoroscopy under anesthesia to investigate the TMT complex [23,24].

Ultrasound — Ultrasound has been used reliably to assess the dorsal Lisfranc ligament [25,26]. As some observational studies suggest that a relatively high percentage of individuals with suspected Lisfranc ligament injuries have ruptured the dorsal ligament [17], ultrasound may be a useful diagnostic tool in such cases. Ultrasound has the advantage of allowing dynamic assessment of both the symptomatic and asymptomatic foot while stress is applied to each. However, evidence supporting the use of ultrasound to diagnose Lisfranc ligament injury remains scant and further study is needed.

CLASSIFICATION OF INJURY — Most classification systems for Lisfranc fracture-dislocations describe patterns of injury that require surgical reconstruction. However, for primary care treatment of these injuries, the following classification scheme can be useful:

●Soft tissue injuries without dislocation – These injuries have normal weight-bearing radiographs and either: (1) magnetic resonance imaging (MRI) showing no fracture or dislocation but peri-ligamentous edema without complete disruption of the ligament, or (2) computed tomography (CT) showing no dislocation or fracture.

●Bony injury with mild displacement – These injuries often have abnormal weight-bearing radiographs with 1 to 5 m of displacement between the first and second metatarsals confirmed on advanced imaging. MRI shows complete ligamentous disruption.

●Bony injury with marked displacement – These injuries always have abnormal weight-bearing radiographs with >5 mm of displacement between the first and second metatarsals confirmed on advanced imaging.

While all tarsometatarsal injuries benefit from the care of a physician experienced in their management, soft-tissue injuries without displacement can be managed nonoperatively, while operative treatment is required for optimal outcomes in bony injuries with even mild displacement (figure 7). (See 'Indications for surgical referral' below.)

INDICATIONS FOR SURGICAL REFERRAL — Given that relatively minor injuries to the tarsometatarsal (TMT) joint complex can ultimately produce severe long-term disability, we recommend referring all injuries involving the TMT joint complex, including injuries thought to be limited to soft tissue injuries, to specialists experienced in the management of these injuries. Debate continues about the appropriate role of surgical versus non-surgical management for a number of TMT joint complex injuries so decision-making about the appropriate course of treatment should involve input from an experienced surgical specialist.

Common indications for surgical referral include the following:

●Proximal fractures of any of the first four metatarsals (because of the frequency of associated dislocations)

●Diastasis (widening) exceeding 1 mm between the first and second metatarsal bases using comparative AP views (ie, comparing injured and uninjured feet)

●Avulsion fracture, or "Fleck-sign," of the medial cuneiform or second metatarsal

●Magnetic resonance imaging (MRI) showing complete ligamentous disruption or computed tomography (CT) or MRI findings consistent with >1 mm subluxation at any of the tarsometatarsal (TMT) joints

DIAGNOSIS — Definitive diagnosis of a tarsometatarsal (TMT) joint complex injury can only be made with advanced imaging studies, although such studies are not necessary in all cases. A TMT joint complex injury should be suspected in any individual complaining of midfoot pain following foot trauma whose examination reveals swelling, tenderness over any of the tarsometatarsal joints, and inability to bear weight or walk without a limp. Plantar ecchymosis is helpful when present but may not appear until to 24 to 48 hours following injury, if at all. While high-energy mechanisms (eg, motor vehicle collision) are most common, TMT injuries can occur from low-energy mechanisms, typically involving an axial load placed on a plantar-flexed foot. This can occur from missing a step when descending a stairway or during sport when one player lands on the heel of another whose foot is plantar-flexed. Weight-bearing plain radiographs of the foot may reveal signs of injury and establish a diagnosis, but magnetic resonance imaging (MRI) or computed tomography (CT) is required to make or exclude the diagnosis definitively.

DIFFERENTIAL DIAGNOSIS — Tarsometatarsal (TMT) joint complex fracture-dislocations often result from major trauma involving the foot. Other significant bony and soft tissue injuries of the lower leg, ankle, hindfoot, midfoot, and forefoot can present in similar fashion. With such injuries, diagnostic imaging, typically including weight-bearing and contralateral plain radiographs, computed tomography (CT), and/or magnetic resonance imaging (MRI), is required to assess structures and delineate the extent of injury.

MANAGEMENT

Acute treatment — Following diagnosis, the acute management of a tarsometatarsal (TMT) joint complex follows the standard approach (PRICE-M):

●Protection: Assuming no other injury, the injured foot is immobilized in a short-leg splint or boot.

●Rest: The patient is not permitted to bear weight on the injured extremity.

●Ice: Ice is applied to the affected midfoot.

●Compression: An appropriate dressing and elastic wrap are applied to the injured foot.

●Elevation: Whenever possible, the injured foot is kept above the level of the patient’s heart.

●Medication: Appropriate analgesia is provided. (See "General principles of acute fracture management", section on 'Immobilization' and "General principles of acute fracture management", section on 'Pain management'.)

Given that relatively minor injuries to the TMT joint complex can cause severe disability, we recommend consultation with surgical specialists for all injuries involving the TMT joint complex, including injuries thought to be limited to soft-tissues. (See 'Indications for surgical referral' above.)

Soft tissue injuries without dislocation — In cases where surgical referral is impractical, non-surgical clinicians with experience managing complex soft-tissue injuries may assume care of the patient with a non-bony TMT joint complex injury. Ideally, this diagnosis is established using advanced imaging, typically magnetic resonance imaging (MRI). Initially, these patients are immobilized in a below-knee cast with non-weight-bearing restrictions. Weight-bearing plain radiographs are obtained every two weeks to ensure that proper alignment is maintained. Injuries that remain stable at six to eight weeks can be converted to a short-leg cast or Controlled Ankle Movement (CAM) boot. If the patient continues to experience pain with ambulation after 10 weeks of non-weight-bearing, repeat advanced imaging is often performed and the conservative management plan is reassessed based on the findings of the repeat study.

Once able to begin weight-bearing, patients with soft-tissue TMT joint injuries should be instructed to increase weight-bearing gradually. For the first two weeks, only partial weight-bearing in a CAM walker or short leg walking cast is allowed [10]. The patient then increases the degree of weight-bearing in two-week intervals. A typical progression involves walking only around the house with no other activity permitted, then walking around the house combined with stationary bicycling every other day while remaining in a CAM boot, and finally unlimited walking with daily stationary bicycling. If pain recurs at any stage of rehabilitation, the patient should be re-evaluated and the previous, less demanding phase of rehabilitation resumed.

Patients perform physical therapy as part of their rehabilitation. Aquatherapy can begin as soon as the patient is out of their non-weight-bearing cast. Care should be taken to avoid full loading of the TMT joint even in the pool for up to 12 weeks. Supervised physical therapy is recommended to ensure that exercises are performed correctly and intensity levels are appropriate. Specific stretching exercises are included to help the patient regain full midfoot function. Custom-made orthoses, stiff sole inserts, or medial arch supports are generally used to protect the injured region depending on the preferences of the medical provider and therapist caring for the patient.

Bony injury — Bony injuries of the TMT joint complex generally require surgical intervention. The rationale for surgery is supported by the following studies:

●In a series of 26 patients with minimally displaced Lisfranc injuries (<2 mm displacement between the first and second metatarsals), 54 percent of patients experienced further displacement during nonoperative management, with a median time to displacement of 18 days [27].

●At two- to six-year follow-up of nonoperative treatment for 22 patients with avulsion-type fractures and 33 patients with simple, nondisplaced intra-farticular fractures, only 55 percent scored over 90 points on both pain and function visual analogue scales [28].

These nonoperative results contrast sharply with results from a retrospective case series of combined ligamentous and fracture injuries. At an average of 3.8 years, all 26 patients treated with operative reduction had excellent pain and function scores on the Short Musculoskeletal Function Assessment [29].

Management of bony injuries involving the TMT joint complex varies widely depending upon the severity and type of injury, age and condition of the patient, and experience and preferences of the surgeon. Likewise, rehabilitation varies depending upon the type of surgical reconstruction performed and patient factors.

Return to sport — Given the significant heterogeneity of injuries involving the Lisfranc joint, decisions regarding return to sport should be made by a clinician with experience managing such injuries. Patients with minor, isolated Lisfranc ligament injuries with no displacement may return to sport in as soon as four weeks, following periods of protective weight-bearing and a slow progression of activity [30]. However, even minimally displaced Lisfranc injuries carry a high risk for further displacement with a subsequent need for surgical repair. In light of this, we discourage early, unrestricted weight-bearing and rapid return to sport. Patients should be told explicitly to expect a slow recovery.

Some experts recommend waiting at least four months before any patient with a TMT joint complex injury of any type returns to sport. Patients who undergo surgery for TMT injuries often require 9 to 12 months before returning to full sport participation. Return to sport should be closely supervised by a knowledgeable physical therapist, athletic trainer, or comparable clinician.

COMPLICATIONS — Tarsometatarsal (TMT) joint complex fractures or dislocations stemming from crush injuries are often associated with significant soft tissue swelling that may result in major acute complications, including vascular compromise, nerve injury, or acute compartment syndrome. (See "Acute compartment syndrome of the extremities" and "Severe lower extremity injury in the adult patient".)

Osteoarthritis and chronic midfoot pain syndromes are common following TMT injury. Some patients may never be able to resume their previous level of activity. While more common in cases of treatment delay and inadequate treatment, these and other complications can occur even in injuries that are promptly and correctly treated.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Lower extremity (excluding hip) fractures in adults" and "Society guideline links: Acute pain management".)

SUMMARY AND RECOMMENDATIONS

●Epidemiology and mechanism of injury – Injuries of the tarsometatarsal (TMT) joint complex (ie, Lisfranc injuries) are not common. However, many such injuries are missed or misdiagnosed, leading to significant long-term pain and disability. TMT joint complex injuries may be caused by high or low energy trauma, and typically involve an axial load placed on a plantar-flexed foot that then forcibly rotates, bends, or is compressed. (See 'Epidemiology' above and 'Clinical anatomy' above and 'Mechanism of injury' above.)

●Clinical presentation and examination – Patients with fractures involving the TMT joint complex typically present following acute foot trauma with pain and swelling of the midfoot and refuse to bear weight or stand on their toes. Plantar ecchymosis is highly suggestive of TMT joint complex injury but may be absent (picture 2). Tenderness may extend across the midfoot. The pronation-abduction (picture 3) and tarsometatarsal squeeze (picture 4) tests are useful confirmatory maneuvers.

Neurovascular testing should include assessment of the dorsalis pedis pulse, as blood flow may be compromised by a dislocation of the second metatarsal. Injuries from high energy trauma may lead to acute compartment syndrome, which can be limb-threatening. (See 'History and examination findings' above.)

●Diagnostic imaging and diagnosis – Diagnosis is made by imaging. A standard three-view foot series of plain radiographs (anterior-posterior, lateral, and oblique) is the initial study obtained:

•In the anterior-posterior (AP) film, the medial border of the second metatarsal should be colinear with the medial border of the middle (intermediate) cuneiform (image 1).

•In the oblique film, the medial border of the fourth metatarsal should be colinear with the medial border of the cuboid (image 1).

•Weight-bearing films that include the contralateral foot are essential for evaluating the integrity of the TMT joint complex (image 2 and image 3).

The accuracy of plain radiographs is limited and advanced imaging with magnetic resonance imaging (MRI) or computed tomography (CT) should be obtained for diagnosis if plain radiographs are unrevealing but clinical suspicion persists. (See 'Diagnostic imaging' above and 'Diagnosis' above.)

●All TMT joint injuries warrant referral – We recommend referring all injuries involving the TMT joint complex, including injuries thought to be limited to soft tissues only, to specialists experienced in the management of these injuries. (See 'Indications for surgical referral' above.)

●Return to activity – Return to full physical activity and sport following TMT injuries requiring operative repair may require 9 to 12 months. Even with proper treatment, some patients are unable to resume their prior level of activity. (See 'Management' above and 'Complications' above.)