Injury to the tarsometatarsal joint complex during fixation of Lisfranc fracture dislocations: an anatomic study.

BACKGROUND

The cause of posttraumatic arthritis in Lisfranc injuries is argued in the literature. The purpose of this study was to determine whether the involved joint surface area increased with repositioning of the guidewire before screw placement.

MATERIALS

Nine matched pairs of cadaveric feet were disarticulated at the tibiotalar joint. Under fluoroscopic guidance, cannulated screws were placed over guidewires after a single pass across the joint for right feet and two passes across the joint for left feet. Specimens were disarticulated through the midfoot, and the digital images of the joint surface were evaluated for joint surface area and the surface area of cartilaginous damage resulting from screw placement.

RESULTS

Mean injury area for the first metatarsal (MT1) was 0.106 cm2 for one pass and 0.168 cm2 for two passes of the guidewire before screw advancement (p = 0.003) The mean injury area for the second metatarsal (MT2) was 0.123 and 0.178 cm2 for one and two passes, respectively (p = 0.018). Four of nine (44%) of the left foot specimens (2 passes of the guidewire) sustained fractures across the MT2 base and three of those specimens also revealed fractures on the middle cuneiform side of the joint (33%).

CONCLUSION

Changing the placement of the guidewire across the midfoot significantly increased the joint surface affected by screw placement. Screws placed plantar to the midline of the joint increased the risk of fracture on both sides of the tarsometatarsal complex.