Clinical History
34-year-old gentleman referred to A&E department after sustaining an injury to his foot.
Imaging Findings
A 34-year-old gentleman presented to the A&E department after an injury at work. A heavy stone fell on his foot which was not protected by any safety garments. The patient complained of pain over the whole foot. Examination revealed a swollen foot with maximal tenderness over the metatarsophalangeal joints. General examination revealed no other injury of note. The patient gave a history of insulin dependent diabetes mellitus. After administering adequate analgesia, the patient was sent for radiological examinations. Antero posterior and oblique view radiographs of the foot were taken. These showed the presence of a fracture of the base of the first metatarsal together with the lateral dislocation of the other metatarsophalangeal joints. These findings were compatible with a Lisfranc fracture. The patient was admitted to hospital. Due to the gross swelling over the foot, the orthopaedic surgeon decided to put a plaster back slab and send the patient home, with very frequent outpatient reviews. After 3 weeks, the patient was admitted to hospital once more. The day after, he was taken to the operating theatre and the fracture reduced and held in place using Kirshner wires under general anaesthesia.
Discussion
Lisfranc fracture dislocation is named after a field surgeon in Napoleon’s army – Jacques Lisfranc, who had described a new amputation technique to treat forefoot gangrene.
Two main forms occur. Homolateral dislocation consists of lateral dislocation of metatarsals one through five or two through five. Divergent dislocation consists of lateral dislocation of metatarsals two through five and medial dislocation of metatarsal one.
The incidence of Lisfranc joint injury was once thought to be very low, it is now, however, no longer considered to be a rarity, partly because of the increasing incidence of major trauma but also because of the realization that even minor trauma can cause disruption of the joint.
The Lisfranc ligament diagonally connects the 1st cuneiform with the base of the 2nd metatarsal. If it remains intact, either an avulsion of the lateral border of the 1st cuneiform or an avulsion of the base or medial border of the 2nd metatarsal occurs. If it tears, these fractures may not occur. Other associated fractures include those of the cuboid, and tarsal navicular.
The standard X-ray views often show only subtle incongruities of the joint or may even be normal. In examining radiographs of the feet the crucial relationships of the foot should be closely inspected. The medial aspect of the second metatarsal should line up with the medial border of the medial cuneiform on an A-P radiograph. Other consistent normal radiographic findings include continuity of the second and third inter-metatarsal space with the space between the lateral and medial cuneiforms on oblique view. Also, the lateral border of the third metatarsal shaft should form a straight line with the lateral border of the lateral cuneiform on the oblique view. On an oblique radiograph, the medial border of the fourth metatarsal should line up with the medial border of the cuboid, while on the lateral radiograph, an unbroken line should be noted on the dorsal border of the first and second metatarsals and their respective cuneiforms. In addition careful examination should be made for small avulsion fractures of the base of the second metatarsal and compression fractures of the cuboid.
Computed Tomography is the gold standard imaging procedure. It should be performed in most of the complex injuries of the tarso-metatarsal region. It allows a 3 dimensional assessment of fractures and surrounding joint stability.
Treatment depends upon type and severity of the injury. Medical treatment is reserved for injuries found to be anatomically stable. This type of injury is best labeled a sprain, although associated fractures in the surrounding bone may be present. Treatment involves immobilization in a well molded non weight bearing short leg cast worn for a minimum of 6 weeks. On the other hand, non anatomic alignment requires open reduction and internal fixation. Clinical outcome depends on restoration of normal anatomic alignment.
The major complications following such an injury are: non anatomic reduction or alignment, post traumatic arthritis and pain with weight bearing.
Differential Diagnosis List
Lisfranc Fracture - Dislocation
Final Diagnosis
Lisfranc Fracture - Dislocation
