Foot injuries commonly occur among athletes, present in
various forms. Stress fractures of the metatarsals and tarsal bones and chronic
soft tissue injuries, such as plantar fasciitis and midfoot sprains to the
joints between the tarsals and metatarsals, are some of the types of foot injuries frequently experienced by athletes. Although considered to
occur infrequently, injuries to the midfoot, particularly along the Lisfranc joint or
the tarsometatarsal joint, require special attention as they
can be considerably impairing to most athletes.
Lisfranc injuries are generally high speed injuries which may develop into serious
deformities of the midfoot joints, normally due to dislocations and/or fractures. From automobile or motorcycle accidents to violent falls onto the foot or severe,
crushing injuries to the foot, these are some of the most common circumstances which
can lead to Lisfranc injuries. In sport settings, this form of foot injury is
less severe, often resulting from a crushing and/or twisting means to the
planted weight-bearing foot. But, when it does occur, Lisfranc injuries can
cause overwhelming consequences for the athlete.
Approximately 16 percent of all sports injuries involve the foot.
Although foot complications can be reasonably common, Lisfranc
injuries are fairly rare. Researchers found that Lisfranc injuries account for up
to 4 percent of all college level football injuries. Severe forms of the
complication can unfortunately not only be season-ending but career-ending as
well for the athlete.
According to researchers, this type of foot injury is more frequent in sports
such as football, with an increased percentage of Lisfranc injuries occurring
in offensive linemen, followed by rugby, as these types of sports usually
involve high levels of contact through the foot. The injury has also been
reported to occur in baseball, gymnastics, horse riding, windsurfing, rodeo
riding and skydiving.
Anatomy of the Lisfranc Joint
The skeletal structure of the foot is intricately supported by ligaments
as well as the intrinsic and extrinsic muscles which extend through the plantar
arch and dorsum of the foot. The Lisfranc complex is a term utilized to
describe the articulation between the midfoot and forefoot. It includes the
joints surrounding the proximal row of cuneiforms and cuboid along with the
distal row of metatarsal heads. Injury to this area of articulations can
develop in various ways.
The natural concave structure of the foot shapes into a solid formation
together with ligaments and other tissues of the midfoot, composing a very
strong and stable structure to prevent the arch of the foot from collapsing.
The Lisfranc joint is comprised of three main sections: first, the
medial column, the joint found between the first metatarsal and the medial
cuneiform which allows for 3.5 mm of dorsal plantar movement; second, the
middle column, consisting of the second metatarsal and its articulation with
the medial and middle cuneiform as well as the lateral cuneiform. This joint is
believed to have greater structural stability and it forms the keystone of the
Lisfranc joint. The third metatarsal and the lateral cuneiform also comprise
the middle column, which allow for less than 1 mm of movement; and last, the
lateral column, the joint between the cuboid and the fourth and fifth
metatarsals, the most mobile articulation, allowing for up to 13 mm of
movement.
Each column is separated by three different synovial capsules,
constituting for three synovial systems. These structures are stabilized by the
metatarsal interosseous ligaments, however, the base of the first and second metatarsals
do not contain any intervening interosseous ligaments, but rather, the second
metatarsal is connected to the medial cuneiform through the plantar oblique
ligament, best referred to as the Lisfranc ligament. This allows each structure
to function independently from the other, an essential function towards the
normal locomotion of the foot. Despite this, the dorsal surface of this joint
is considerably unstable, often causing the metatarsals to dislocate as a
result when increased pressure is distributed to the foot.
Mechanism of Injury
The area of the midfoot is also supported by overlapping tendons. Each
tendon belongs to the tibialis anterior and attached to the dorsum of the first
metatarsal base and medial cuneiform, the peroneus longus which attaches to the
plantar and lateral section of the first metatarsal, and the tibialis posterior
tendon, attaching to the navicular to indirectly control the position of the
arch. Moreover, the plantar fascia and the intrinsic muscles of the foot add
additional support to the arch of the foot.
Lisfranc injuries affecting the middle of the foot can be categorized
from low energy to high energy. Low energy injuries can be identified as
ligamentous in nature where minor dislocations and bone fractures occur. High
energy injuries typically occur after automobile accidents where midfoot
dislocations and fractures occur.
Low energy Lisfranc injuries of the midfoot commonly occur in athletes.
For instance: a forced hyper-plantar-flexion of the midfoot where the foot
remains in a fixed motion can cause injury to the foot. In horse riders and
windsurfers, this circumstance occurs frequently because their foot is usually
fixed by a strap. In the case a rider or surfer falls backwards during an
accident, the load of the body pushes the foot into a position of intense
plantarflexion while the foot is still tied to the strap; also, a direct impact
to the heel while the foot remains locked in plantarflexion can also cause a
Lisfranc injury. This scenario results when weight falls onto the back of the
heel during the pushing off process of movement, forcing the structures of the
foot to compress. This can be seen in football where a player is about to push
off and another player falls on that foot while it’s in a position of
plantarflexion. It may also result in skydivers who land when their foot is in
this same position; then, a crushing injury to the foot while it is in a
pronated, weight-bearing position, can cause this type of foot complication. Because
of the structure of the foot, these types of injuries are usually less common,
however, a strong compressing force through the midfoot may stretch and damage
the plantar ligaments of the Lisfranc joint.
In comparison
with the strength of the plantar ligaments, dislocations in the direction of
the dorsal ligaments are much more common than plantar dislocations, generally
due to the differing forces being placed on the foot in normal injury
mechanisms.
Symptoms
A majority of sports injuries are often
undiagnosed and Lisfranc injuries can also be subtle and therefore difficult to
detect. Many times, when an athlete has also suffered ankle injuries or foot
fractures, healthcare professionals can overlook Lisfranc injuries. Also, if
athletes are not able to properly describe the mechanism of their injury to a
medical specialist, it can be challenging for doctors to correctly diagnose
injuries to the midfoot.
After several days or weeks when the original
injury occurred, the foot will be painful in the area of the midfoot along the
dorsal complex of the Lisfranc joint and in the plantar arch. The intrinsic foot
muscles will also display palpable spams.
Athletes with Lisfranc injuries will often
have a hard time walking, specially during the push-off stage of gait, along
with palpation pain over the first tarsometatarsal joint and between the first
and second metatarsals and their subsequent joints with the tarsals. There may
also be considerable swelling over the midfoot, to the point where the
observable veins are concealed. Furthermore, ecchymosis or bruising may occur
in the plantar arch of the foot.
Upon clinical assessment, the affected athlete
will experience pain along the first tarsometatarsal joint through
supination/pronation of the midfoot and through dorsiflexion/abduction of the
forefoot. The healthcare professional may also squeeze the metatarsal heads
together, to determine if the individual feels symptoms of pain. The medical
specialist may also perform the piano key test, where they will grasp each
individual toe and move them in a plantar and dorsal position, to determine the
presence of Lisfranc injuries.
Imaging
X-Rays
In a patient’s X-rays, healthcare
professionals commonly look for fractures at the base or neck of the
metatarsals, they examine whether a small avulsion is present along the medial
base of the first or second metatarsal, they view the orientation of the
metatarsals to make sure they correspond to the tarsal bones, perform an
evaluation through the presence of displacement between the first and second
metatarsal heads, more than 2 mm of this seen in an X-ray is a diagnosis for a
Lisfranc injury, and finally, upon examination on a patient’s X-rays,
healthcare professionals will check whether the medial cortex of the fourth
metatarsal lines up with the medial border of the lateral cuneiform where there
is no interruption of the dorsal cortical line of the first metatarsal to the
medial cuneiform.
Current studies found that some X-rays missed
barely over 30 percent of subtle Lisfranc joint separations, suggesting that
various views of imaging testing may be more sensitive than others. Therefore,
CT scans are generally preferred to assess the presence of Lisfranc injuries.
CT Scans and MRI
CT scans can
also be extremely helpful to evaluate alterations of the joint spaces in the
foot as well as assessing any relating fractures. A CT scan can benefit an X-ray
diagnosis and can be utilized together with the X-ray to determine whether
surgery may be required. Although not frequently used, MRI can also be utilized
to evaluate any soft tissue injuries in relation to Lisfranc injuries, such as
major tendon disruptions like the peroneus longus tendon.
Classification
Lisfranc injuries are categorized in systems associated to the
severe high energy form of the issue. However, a different
classification system created by a group of researchers was developed for athletes with Lisfranc injuries. Each stage of injury in every athlete can be classified as follows: ability to weight-bear; local point
tenderness over the Lisfranc ligament; and a radiographic appearance of the
Lisfranc joint.
The three stages of a Lisfranc injury are as follows:
Stage 1
With stage 1 Lisfranc injuries, the athlete is able to weight-bear, but,
they cannot return to play. They may also experience tenderness over their
first tarsometatarsal joint. Radiologically, results will show no diastasis
greater than 2 mm between the first and second metatarsal joint with no collapse
of the arch as measured by the cuneiform, fifth metatarsal vertical distance.
Stage 2
With stage 2 Lisfranc injuries, athletes are able to partially weight-bear
and they cannot return to play. Moderate tenderness may be experienced over the
medial aspect of the first tarsometatarsal joint. Radiologically, evaluation
results will indicate diastasis between 2 to 5 mm between the first and second
metatarsal joint with no collapse of the arch as measured by the cuneiform,
fifth metatarsal vertical distance.
Stage 3
With stage 3 Lisfranc injuries, athletes have an inability to
weight-bear. Severe tenderness is felt over the medial aspect of the first
tarsometatarsal joint where there is a diastasis greater than 5 mm and collapse
of the medial arch.
Signs a Foot or Ankle Injury is Serious
By Dr. Alex Jimenez