Expert Insights On Detecting Lisfranc's Injuries

Start Page: 50

How Do Lisfranc’s Injuries Occur?

Lisfranc’s injuries can occur through either direct or indirect forces applied at or through the tarsometatarsal joint. The historical description of injury was associated with equestrian falls. When the forefoot was essentially “caught” in the stirrup in a fixed position, it created a lever, whereby a backward fall of the mount would produce a violent plantarflexory force through the midfoot as the hindfoot was free to move about in all cardinal planes.

Most commonly today, these injuries occur in work-related activities, slips and falls, athletic and recreational pursuits (such as snow boarding and other “impact” athletics) and motor vehicle accidents. While the advent of advanced automobile passenger restraint systems has directly improved the survival rate of those who suffer blunt head and chest trauma, lower extremity injuries remain prevalent.

Although an absolute mechanism of injury is unknown to exist, the consensus on Lisfranc’s injuries is that they are caused by either direct or indirect trauma. Direct, blunt or crushing trauma may impart significant soft tissue edema, vascular compromise, trauma blister formation and the potential sequelae of compartment syndrome. If you suspect compartment syndrome, you should perform a compartmental pressure evaluation.

Indirect mechanisms of injury generally occur via an axial load and plantarflexory displacement in concert with an applied abduction force and may also predispose these patients to compartment syndrome.

Here is a fracture dislocation of the Lisfranc’s complex with lateral displacement of the second, third, fourth and fifth metatarsals and an associated communited first metatarsal fracture. Note the retained alignment of the first metatarsal/cuneiform art
Here we see the medial, central and lateral compartments of the Lisfranc’s joint complex.
It is common to see moderate edema and ecchymosis after an acute Lisfranc’s joint fracture/dislocation.
A preoperative lateral view of a Lisfranc’s injury.
The post-op lateral view after the author performed open reduction, internal fixation.
By David Caldarella, DPM, and Celeste Borchers, DPM

Lisfranc’s injuries, as found at the tarsometatarsal joint, are rare, according to the literature. Only 1 percent of all fractures are found at the tarsometatarsal articulation with an incidence of one per 55,000 people per year.1 These injuries are two to four times more likely to occur among young to middle-aged men as opposed to female patients.1-3 Overall, though, the injury is still a rare phenomenon. Aitken and Poulson reviewed 82,500 fractures over a 15-year period and found only 16 cases of Lisfranc’s fractures.4
But are these injuries as rare as we think they are? The historically low reported incidence may be a function of often misdiagnosed and/or “underappreciated” tarsometatarsal injuries. Indeed, these injuries often present with subtle clinical and radiographic findings. Clearly, a strong appreciation of the complex functional anatomy and an appropriate index of suspicion are essential to detecting and treating Lisfranc’s joint injuries.

Reviewing The Anatomy Of The Lisfranc’s Joint
The Lisfranc’s joint or tarsometatarsal articulation is comprised of five metatarsal bases, three cuneiforms and the cuboid. The skeletal elements are joined together by dorsal, interosseous and plantar ligaments and the articular capsule of the joints.
Transversely, the Lisfranc’s complex forms a convex arch anteriorly. In the frontal plane, it forms a symmetric arch, with the wedge-shaped base of the second metatarsal acting as the “keystone,” affording a high degree of osseous stability in this plane.5

Metatarsals one, two and three articulate respectively with the medial, intermediate and lateral cuneiforms, which in turn articulate with each other. The architecture of the second cuneiform creates a recess of sort for the interposition of the second metatarsal base, which articulates with each cuneiform. This creates a mortise and “locks” the entire tarsometatarsal complex.6
The skeletal elements of this complex are joined together by capsuloligamentous restraints. The articular capsule is divided into the medial, central and lateral compartments. This capsule is formed by a fibrous membrane lined internally with synovium. The first metatarsal and medial cuneiform compromise the medial compartment, while the central compartment includes the second and third metatarsal and their respective cuneiforms. Finally, the lateral compartment is defined as the fourth and fifth metatarsals and the cuboid.
DePalma, Santucci and Sabetta studied 20 cadaveric feet and found significant variability exists in the course and structure of the reinforcing ligaments across Lisfranc’s joint.5 All specimens showed a ligamentous system consistent with dorsal, interosseous and plantar ligaments.
The dorsal ligaments follow a longitudinal, oblique or transverse course. The longitudinal and oblique ligaments unite the bases of the metatarsals with their respective tarsal bones while the transverse ligaments include the dorsal intertarsal and intermetatarsal ligaments.
The interosseous ligaments transversely connect the lateral four metatarsals, but are absent between the first and second. Instead, the second metatarsal is connected to the first tarsometatarsal joint obliquely from the proximal medial aspect of the second metatarsal base to the lateral distal aspect of the medial cuneiform by the Lisfranc’s ligament.1, 5-7 This ligament is the largest of the complex. The absence of a ligament connecting the first metatarsal to the tarsal bones is an inherent weakness of this complex and is responsible for the specific injury patterns you would see with these injuries. The interosseous ligaments connect the cuneiforms and cuboid, and are the most powerful attachments between these bones.

image description image description

Post new comment

  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.

More information about formatting options

Enter the characters shown in the image.