What is a Lisfranc injury?
The midfoot is the middle part of the foot and transfers the forces generated by the muscles in the leg to the forefoot and toes during walking. It is comprised of multiple joints formed by the tarsal bones, including the 1st-5th tarsometatarsal joints collectively known as the Lisfranc joint. This midfoot joint complex is named after the French surgeon, Jacques Lisfranc de Saint-Martin, who served in Napolean’s army during the 1800s. The Lisfranc joint is important in stabilising the longitudinal arch of the foot during weight-bearing. The Lisfranc ligament is attached to the base of the 2nd metatarsus and medial cuneiform, and is a key stabiliser of the Lisfranc joint. Injury to the Lisfranc joint or ligament can result in instability of the arch of the foot which in turn, can lead to a flatfoot deformity and/or midfoot arthritis. The latter condition can cause dysfunction and be especially problematic in the young or physically active, because definitive surgical treatment is limited to a fusion of the symptomatic arthritic joint.
How do Lisfranc injuries usually present?
Lisfranc injuries can occur from a low or high energy mechanism, such as from a simple fall or sporting injury, or secondary to a fall from height or a motor vehicle accident, respectively. The mechanism is usually caused by a rotational force or an axial load with the foot hyper-plantarflexed. Lisfranc injuries can be bony or ligamentous, or result from a combination of fractures or injury to the ligaments of the tarsometatarsal joints. Patients with an acute Lisfranc injury classically present with a painful, swollen and bruised midfoot, and an inability to weight-bear on their injured side. In particular, there is often bruising on the plantar aspect or sole of the midfoot.
What are the management options for a midfoot Lisfranc injury?
For acute injuries, it is recommended that you remain non-weight-bearing through your injured foot until you have been assessed by an Orthopaedic Surgeon. Non-operative treatment for an undisplaced and stable midfoot Lisfranc injury generally necessitates immobilisation of the injured foot in a below-knee backslab/cast, and then offloading with a CAM boot (and medial arch support orthotic) and activity restriction for approximately 3 months. Surgical open reduction and internal fixation is indicated for injuries with any displacement of the Lisfranc articulation to try restore joint congruity and stability, and reduce the risk of post-traumatic arthritis in the midfoot. Fixation of the Lisfranc joint normally involves using plates and screws to bridge the injured tarsometatarsal joints, and/or a suture button implant/suture tape construct to directly stabilise the Lisfranc ligament. The plates function like internal clamps to hold the joints reduced until the surrounding bones and ligaments have healed, and are typically removed at 4-5 months after the index procedure. Alternatively, primary fusion of the medial tarsometatarsal joints can be considered for non-reconstructable intra-articular fractures or pure ligamentous Lisfranc injuries.
What is the recovery after surgical fixation of my Lisfranc injury?
After surgical fixation of your Lisfranc injury, you will be non-weight-bearing through your operated foot for 6 weeks, and can then gradually progress from partial to full weight-bearing over another 6 weeks. You will be immobilised in a below-knee plaster backslab/fibreglass cast for up to 6 weeks, and can then transition to a CAM boot with a medial arch support orthotic. You will need to wear your CAM boot when ambulating only until 12 weeks post your surgery. Once your backslab/cast has been removed, you will be encouraged to start ankle and foot range of motion and stretching exercises to reduce your stiffness, and to commence exercising in the swimming pool or doing hydrotherapy. For most patients, it will take 2-3 weeks for your wounds to heal, 4-5 months for your Lisfranc joint to regain its functional stability, 6-7 months before you are reasonably comfortable walking in normal shoes with medial arch support orthotics, and at least 12 months for the swelling in your foot to subside and for full recovery to your new baseline level.
What can I expect after a midfoot Lisfranc injury?
Unfortunately, patients who have sustained a Lisfranc injury may experience chronic non-specific stiffness and/or an ache in their midfoot after increased physical activity. They may also have decreased standing and walking endurance, and should preference low impact-loading activities for their work and exercise/recreation in the long term. In addition, patients with a previous midfoot or Lisfranc injury are advised to wear shoes with inbuilt support for the longitudinal arch of their foot or to use medial arch support orthotics lifelong, and to try maintain a healthy weight