A Lisfranc (midfoot) injury is a significant injury that often has a prolonged recovery time. Fracture of the midfoot bones and/or disruption of the midfoot ligaments leads to pain, swelling, and often an inability to weight-bear.
During normal standing and walking the ligaments of the midfoot are subject to forces that are 2-3 times body weight. These ligaments and bones must heal before normal walking can occur and this often takes many months.
A stable Lisfranc injury (midfoot sprain) occurs when some of the midfoot ligaments are not completely torn and the bones and midfoot joints are in their normal position.
Stable Lisfranc injuries are treated with rest, immobilization, and often a period of non-weight-bearing. A displaced Lisfranc injury is associated with disruption of the midfoot ligaments leading to malalignment of the tarsometatarsal joint.
Because of this instability, these injuries are usually treated with surgery to reposition and stabilize the joints.
This joint was originally described by Lisfranc (a Napoleonic era field surgeon). He noted that riders who got their foot caught in the stirrup when they were knocked off their horses would suffer a serious injury to this joint.
As a result he often needed to performed an amputation through the middle part of the foot. That joint through which he amputated now bears his name as does the major stabilizing ligament that runs from the medial cuneiform to the 2nd metatarsal.
The Lisfranc Joint
The Lisfranc joint is the point at which the metatarsal bones (long bones that lead up to the toes) and the tarsal bones (bones in the arch) connect.
The Lisfranc ligament is a tough band of tissue that joins two of these bones. This is important for maintaining proper alignment and strength of the joint.
How Do Lisfranc Injuries Occur?
Injuries to the Lisfranc joint most commonly occur in automobile accident victims, military personnel, runners, horseback riders, football players and participants of other contact sports, or something as simple as missing a step on a staircase.
Lisfranc injuries occur as a result of direct or indirect forces to the foot. A direct force often involves something heavy falling on the foot. Indirect force commonly involves twisting the foot.
Types of Lisfranc Injuries
There are three types of Lisfranc injuries, which sometimes occur together:
Sprains. The Lisfranc ligament and other ligaments on the bottom of the midfoot are stronger than those on the top of the midfoot.
Therefore, when they are weakened through a sprain (a stretching of the ligament), patients experience instability of the joint in the middle of the foot.
Fractures. A break in a bone in the Lisfranc joint can be either an avulsion fracture (a small piece of bone is pulled off) or a break through the bone or bones of the midfoot.
Dislocations. The bones of the Lisfranc joint may be forced from their normal positions.
The symptoms of a Lisfranc injury may include:
- Swelling of the foot
- Pain throughout the midfoot when standing or when pressure is applied
- Inability to bear weight (in severe injuries)
- Bruising or blistering on the arch are important signs of a Lisfranc injury. Bruising may also occur on the top of the foot.
- Abnormal widening of the foot.
Lisfranc injuries are sometimes mistaken for ankle sprains, making the diagnostic process very important.
To arrive at a diagnosis, the foot and ankle surgeon will ask questions about how the injury occurred and will examine the foot to determine the severity of the injury.
X-rays and other imaging studies may be necessary to fully evaluate the extent of the injury.
The surgeon may also perform an additional examination while the patient is under anesthesia to further evaluate a fracture or weakening of the joint and surrounding bones.
Stable Lisfranc injuries are usually treated non-operatively. This involves immobilization in either a cast or a prefabricated boot.
Patients often need at least a 6-week period where they are either non-weight bearing or minimally weight bearing.
In a stable injury the midfoot ligaments are strained but still intact, so once an adequate amount of healing has occurred patients can increase their activity level. However, even with a non-displaced injury, full recovery can take many months..
Displaced (Unstable) Lisfranc injuries are usually treated surgically. Surgery is performed to restore joint alignment and stabilize the joint(s) with screws and sometimes a plate.
This allows the bones and the ligaments to be held in place which gives the ligaments a chance to heal. In some cases it is necessary to fuse the involved joints (connect the two bones forever) eliminating the motion altogether.
It is not uncommon that, once the injury has healed, removal of the hardware will be necessary requiring another surgical procedure.
Recovery From Surgery
The post surgical treatment is dependent upon the nature of the injury, specific surgical treatment and the surgeons preference. For a major Lisfranc injury a typical recovery protocol would include:
- 6- to 8-week period of non-weight bearing in a splint/cast/brace/boot.
- Gradual transition to weigh tbearing as tolerated in a walking boot for an additional 4-8 weeks.
- Wean from the boot to a stiff sole shoe at 10-14 weeks from surgery.
A displaced injury takes many months to recover. The majority of the recovery occurs in the first 6 months, but it is often a year or more before patients reach their point of maximal improvement.
If the surgical treatment fails or the joint damage from the injury leads to severe arthritis, then a fusion (arthrodesis) of the Lisfranc joints may be necessary.
Despite the stiffness of a fused joint most patients with successful fusion of the midfoot joints have good function of the foot.