THE UNDESCRIBED ARCH PATTERNS OF LISFRANC INJURIES

Abstract

Introduction: The unique architecture of the tarsometa-tarsal joints gives rise to a complex articulation between the midfoot and forefoot. The Lisfranc injury has a classic pattern leaving its telltale signs in an arch pattern starting at the medial cuneiform, continuing through the second, third and fourth tarsometatarsal regions and finally may end as a fracture of the cuboid. However, various other patterns and classifications of Lisfranc fracture dislocation have been recorded in medical literature.

Aim: To highlight the hitherto undescribed arch patterns of Lisfranc injuries.

Methodology: 8 patients with atypical Lisfranc injuries were studied prospectively.

Arch patterns: In 2 patients the arch started at the medial aspect of the ankle with injury to the medial malleolus or the deltoid ligament, passed through the tarsometatarsal region and ended at the cuboid. In one patient the arch started at the tarsometatarsal joints and ended at the lateral malleolus and in another patient the lateral end point resulted in tear of the calcaneofibular ligament. One patient had the medial starting point at the Lisfranc ligament but the arch of injuries went through the forefoot fracturing the midshaft of the 2nd, 3rd and 4th metatarsal shafts without injuring the tarsometatarsal region, thus forming an arch pattern much more distal than usual. Six of the 8 patients had operative management. On follow up, in terms of activities of daily living, 75% had excellent function of the foot. It is not the aim of this paper to highlight the management of these injuries.

Conclusion: In the process of listing the telltale signs of a Lisfranc injury it is mandatory to bear in mind that the arch of injuries may extend to as proximal as the ankle joint or as distal as the forefoot and this will enable us to define the entire spectrum of the Lisfranc injury, however atypical it may be.