The Lisfranc joints of the foot make up part of what is known as the midtarsal or mid-portion of the foot. Jacques Lisfranc was a field surgeon in Napolean's army who first described the partial amputation of the foot occurring at the joints that articulate with the base of all the metatarsal bones. This is known as the tarso-metatarsal articulations.
A Lisfranc joint injury is not limited to one type of injury in the mid-foot but can be any number of issues dealing with these articulations. Injuries to the midtarsal region are fairly common and are two to three times more common in men than women. Because of the close nature of all these small joints, injuries to the midtarsal region can be easily missed or misdiagnosed. Lack of a proper timely diagnosis to a Lisfranc joint injury can have debilitating consequences including early arthritis in the joint, compression of the arch height, chronic pain in the middle portion of the foot and instability within these joints that can lead to alterations in a person's gait.
The most common type of Lisfranc joint injury to this portion of the foot is from high impact injuries such as motor vehicle accidents where the foot is planted against the floor or gas pedal and the high impact of the crash is absorbed by the foot in the middle portion.
Repetitive stress to these small joints as seen for example in athletes can also lead to damage in this section of the foot, resulting in Lisfranc joint injuries.
Lisfranc's joint essentially divides the forefoot from the midfoot through its various articulations. The articulations consist of the joint formed between the first metatarsal bone and the first cuneiform bone, the second metatarsal bone and the second cuneiform bone, the third metatarsal bone and the third or lateral cuneiform bone, the fourth and fifth metatarsal bones and the cuboid bone. The stability of this portion of the foot is provided by these small articulations and the many ligaments which are interposed throughout the area. The second metatarsal and second cuneiform form the cornerstone of the arch and is the most stable joint among all the Lisfranc joint articulations.
Interestingly, if you look at the bases of each of the metatarsal bones and compare it to a roman arch, you will see a similarity in that the tops of the bones are wider then the bottom portion of the bone which is the same as the roman arch pictured here. This type of architecture further adds to the stability in this portion of the foot.
Lisfranc joint injuries can be the result of direct and indirect injury. Direct injury would be trauma as in a crush injury where something very heavy falls on the top of the foot. These types of injuries overall, have poorer outcomes because of the damage done to the surrounding soft tissue including ligaments and tendons as well as blood vessels that travel through this area. Indirect Lisfranc joint injury may occur as the result of the previously mentioned car accident scenario. In most of these cases while the driver is forcefully pressing down on the brake, which is forcing the foot in a plantarflexed position (pressing downward), the sudden impact of hitting the car in front of you results in a force which forces the foot upward and thus the Lisfranc joints absorb the brunt of this impact.
The other type of indirect Lisfranc joint injury usually occurs in sports, where the athlete has the foot planted on the ground in a certain position and then is hit by another player which again jolts the foot with the Lisfranc joints bearing the burden of this impact. This type of injury is seen very frequently in football players as well as soccer and basketball players.
The last type of indirect Lisfranc joint injury is from falling or twisting type injuries where the foot is torqued in a certain position. This is very common in falls.
Over the years various authors have tried to further classify the joints of the midtarsal region in an effort to offer better types of prognosis depending on which part of the mid-foot is injured. Based on this, suffice it to say that injuries to the inside and outside portions of the Lisfranc joints have a better prognosis than injuries to the middle portion which is made up of the second metatarsal bone and middle (second) cuneiform bone.
The diagnosis of a Lisfranc injury can be difficult depending on the circumstances. Obviously in cases of direct trauma there will be swelling and tenderness. An x-ray may show an abnormal widening of space between one or more of the articulations as well as any possible fracture. The problem here with this type of injury is that because of the close approximation of all these small bones, a small fracture may go unnoticed, even in cases of direct trauma, where a fracture is being specifically looked for.
In the indirect forms of Lisfranc injuries the symptoms are more subtle. The patient may have difficulty walking but there may not be the swelling and palpable tenderness that one will see in the direct trauma type.
It is generally assumed that if there is eccymosis (black and blue) on the plantar part of the foot in the mid arch area, then there is a definite Lisfranc injury. Generally, manual pronation and abduction (flattening out of the foot and movement of the forefoot outwardly) of the foot will also cause pain as these motions stress the midtarsal joints, so if there is an injury there will be increased pain.
From an imaging standpoint, x-rays are usually performed first. This may include non-weightbearing and weighbearing x-rays. We then look for differences in the joints that are produced by the stresses in the midtarsal joint from bearing weight. The problem here, of course, is that for those that are in a lot of pain, bearing weight on the foot may be impossible. In these individuals where just a non-weightbearing x-ray fails to help the doctor other studies such as an MRI, bone scan or a CT scan may prove very beneficial.
TREATMENT OF LISFRANC JOINT INJURIES
Management of Lisfranc injuries is determined by the severity of the injury. Non-surgical treatment is limited to those injuries where the midtarsal joints are stable, there is no dislocation of any of the joints involved and sign of fracture other than a simple fracture. Treatment would consist of a walking boot for upwards of ten weeks, initially the patient may have to be non-weightbearing if he or she is experiencing too much pain while trying to walk, even with the walking boot. Follow-up x-rays are recommended during this period of time, just to make sure no mal-alignment has occurred.
In more severe Lisfranc injuries, surgical intervention is usually indicated. The goal of surgery is to adequately re-align these small joint and once again create a stable joint structure. Most cases of surgery in this area will require the insertion of hardware including screws, possible plates, possibly k-wires in an effort to reduce and fractures and maintain proper alignment. In some cases fusion of some of these small joints may be necessary. Following surgery, most patients will be placed non-weightbearing for a number of weeks which will then be followed by physical therapy. Your surgeon may recommend an orthotic afterwards to further maintain stability at the mid portion of the foot.