Lisfranc (Midfoot) Injuries
The tarsometatarsal joints, or Lisfranc joints, are the midfoot joints where the long metatarsals meet the midfoot (tarsal) bones. Lisfranc fractures and fracture-dislocations describe a broad spectrum of injuries where the Lisfranc complex is disrupted by either tearing of soft tissues, fractured bones, or both. Injuries range from mild cases with partial sprains of the Lisfranc ligaments, through to severe fractures with dislocation of the midfoot joints.
The injury pattern was initially described by Jacques Lisfranc de St Martin, a Napoleonic-era French surgeon who first noticed the injury in horse riders who fell from their horses, with their foot remaining trapped in the stirrup. The most common causes today for these injuries are motor vehicle accidents, slips and falls, and contact sports.
What are the symptoms of a Lisfranc injury?
The common symptoms are swelling and pain in the midfoot, as well as discomfort with weightbearing. Bruising is common, and bruising on the bottom of the foot around the arch is a clue that a Lisfranc injury has occurred. Subtle injuries may present with only mild pain, and it may be possible to put some weight on the foot. Severe injuries can result in deformity of the foot and significant pain.
How is a Lisfranc injury diagnosed?
The diagnosis of a Lisfranc injury is made after taking a history of the injury and the mechanism, a thorough physical examination of the foot, and X-rays and other tests. Examination of the foot can be very important, particularly for subtle injuries which require a high index of suspicion. X-rays may show broken or displaced bones in the midfoot, and a CT scan is often ordered to further evaluate the bony architecture. An MRI scan is sometimes ordered if evaluation of the ligaments is required. Weightbearing or stress X-rays are sometimes used to evaluate the stability of the Lisfranc complex.
What are the treatment options?
If the bones are not displaced from their normal positions, and the ligaments and soft tissues are not significantly damaged, non-surgical treatment with casting and regular X-ray checks may be all that is required.
If the bones and joints have moved due to fractures or soft tissue tearing, then surgery is recommended to restore the normal anatomy of the midfoot. This involves the placement of screws and plates to hold the bones in their normal positions. This metalwork sometimes needs to be removed once everything has healed up.
What is the recovery and prognosis?
Lisfranc injuries are regarded as serious injuries, and even minor injuries can have a prolonged recovery period. Patients are normally immobilised in a below knee cast or boot for 6 weeks, with no weightbearing during this time, and often a further 4-6 weeks in a boot is required once walking is started. Return to maximum function often takes up to one year after the injury.
Long term outcomes depend on the severity of the initial injury. Some patients won’t get back to their pre-injury function or sport, even with well-performed surgery. It is common to sustain cartilage damage at the joint surfaces during the initial injury, and some people develop midfoot arthritis and ongoing pain down the track. Some patients require further surgery to fuse the midfoot joints to relieve arthritis pain.
What are the possible complications of surgery?
Lisfranc injuries that are missed or untreated can result in collapse of the arch of the midfoot with significant pain, and the development of arthritis. When surgery is performed, risks include damage to the structures around the top of the foot (nerves, blood vessels, tendons, muscles), as well as a risk of wound infection or breakdown.