Whole Foot
The Lisfranc joint is a joint that many people are unaware of in the middle part of the foot. It connects the metatarsal bones that go to each of the toes to the square bones in the back of the foot, the tarsals. This joint only moves a few degrees, but it is the capstone of the arch of the foot. Like the capstone in a stone arch, without it, the arch collapses.
Lisfranc injuries occur when the foot is forcibly turned to the outside when stepping down or pressing down on the foot. The injury can vary from a mild sprain or stretching of the ligaments to a complete tear or dislocation of the joint. Some injuries can include fractures of the bases of the metatarsals. Usually, these injuries are high-energy injuries such as falls, motor vehicle accidents or athletic injuries. They are very easy to miss on radiograph.
The principle of treatment is rest, ice and elevation like any other sprain in cases where the degree of injury is slight. However, these injuries take considerably longer to improve than ankle sprains. Some degree of pain can be present for several months. Often walking early on in a prefabricated walking boot can help. When the ligaments have been torn and the joints have been separated even a little bit, surgery is necessary.
Traditionally, surgical treatment involved moving the joint back into its original position and placing screws across the joint to keep it aligned until the ligaments heal. Orthopedic surgeons were hoping that the ligaments would heal at their natural length and strength this way because there is no technique for direct repair. After the operation, no weight bearing is allowed for six to twelve weeks and the screws are often removed at some point afterwards. People often continued to have pain despite the normal appearance of the radiographs. Recent studies have caused many orthopedic surgeons to change their approach1, 2.
Another approach is arthrodesis or fusion of the Lisfranc joint in an effort to re-establish the stability of the arch. In this procedure, the joint and the hard bone directly underneath it are removed. The bones are then pressed together and allowed to heal like a fracture would so that the two bones become a single bone. The recovery for this procedure is very similar to fixation. Comparisons between people with ligamentous Lisfranc injuries who have been treated with the traditional fixation and those who have had their joints fused indicate that the people with the fusions had less pain and better function than people who had traditional fixation. This is currently the suggested technique in my practice.
