INJURY FOCUS

LISFRANC INJURY OF THE FOOT

clinical findings and negative routine x- rays, stress films in eversion-pronation and inversion-supination should be obtained under general anaesthetic (9).

By Ian Horsley, MCSP, SRP

The Lisfranc injury to the forefoot is thought to have originated with Napoleon’s surgeon named Jaques Lisfranc, who while serving on the Russian front, described a new amputation tech- nique to treat forefoot gangrene from frost bite. This developed after riders fell from their horses with their foot caught in the stirrup (1,2). The technique involved amputating the forefoot by following the tarso-metatarsal joint line in order to avoid having to take the time to cut through bone.

A Lisfranc injury encompasses everything from a sprain to a complete disruption of the normal anatomy of the tarso- metatarsal joints (3). The eponym Lisfranc’s joint refers to the area where the metatarsals meet the three cuneiform bones and the cuboid and describes the physical boundary between the rigid mid foot and the more mobile forefoot (4).

The Lisfranc ligament (see Fig.1) is a strong and thick ligament, deeply situated in the sole of the foot. It has a relatively broad proximal attachment to the plantar surface of the medial cuneiform adjacent to the first tarso-metatarsal articulation. From this attachment the ligament runs distally and laterally to attach to the medi- al aspect of the base of the second metatarsal. The ligament blends partially with the capsules of the first and second tarso-metatarsal joints.

Injuries to the tarso-metatarsal joint are uncommon and can be difficult to diagnose (5) but should be considered in all cases of ‘midfoot sprain’ of the sportsperson. The reported incidence of Lisfranc joint fracture dislocations is approximately 1 per 55,000 people per year (1,6). They are commonly misdiagnosed during the initial examina- tion, with as many as 20% of Lisfranc joint injuries being missed on the initial antero- posterior and oblique radiographs (1,4,7,8).

8 SportEX

Anatomy The Lisfranc joint is composed of the artic- ulations between the five tarso-metatarsal joints (3,6), although Myerson (10) sug- gests that to avoid confusion the term “Lisfranc joint complex” should be used to refer to tarso-metatarsal articulations and the term “Lisfranc joint” should be applied to the medial articulation involving the first and second metatarsals with the medial and middle cuneiforms.

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Figure 1: The Lisfranc ligament showing the tarso- metatarsal articulations (inferior view)

In a retrospective review of x-rays of 750 patients treated for tarso-metatarsal joint injuries or metatarsal fractures, Vuori and Aro (2) found Lisfranc joint injuries in 9% (66) of patients. Nineteen percent (12) patients had a total dislocation, 71% (47 patients) had a partial dislocation, and 11% (7 patients) a substantial injury of the Lisfranc joint.

Although they are classically described in the trauma literature (4), they have rarely been described as a result of sports partic- ipation. The most common mechanism of injury appears to be through an axial load applied to a plantarflexed foot. This causes rupturing of the tarso-metatarsal ligaments on the dorsal aspect of the foot. If the injury progresses it may cause a fracture on the plantar aspect of the metatarsal base or rupturing of the plantar capsule.

Due to the fact that 20% of tarso- metatarsal fracture-dislocations are over- looked, in the presence of suggestive

Figure 2: Lisfranc injury showing the widened space between the 1st and 2nd metatarsals (superior view)

Transverse ligaments join the bases of all the metatarsals with the exception of the articulation between the first and second metatarsals (3,6).

The Lisfranc ligament spans the medial cuneiform and the base of the second metatarsal, originating from the lateral plantar aspect of the medial cuneiform. It is the thickest of the ligaments in the region providing the only soft-tissue link between the medial ray and metatarsals, affording the area its stability (11). The joint capsule and dorsal ligaments provide only minimal

©1999 Primal Pictures Ltd