Screw fixation compared with suture-button fixation of isolated Lisfranc ligament injuries.

Abstract

A cannulated screw is currently used to reduce and stabilize diastasis at the Lisfranc joint. The screw requires removal and may break in situ. A suture button does not have these disadvantages, but it is not known if it can provide stability similar to that provided by a cannulated screw or an intact Lisfranc ligament. The objective of the present study was to compare the stability provided by a suture button with that provided by a screw when used to stabilize the diastasis associated with Lisfranc ligament injury. Fourteen fresh-frozen, paired cadaveric feet were dissected to expose the dorsal region. A registration marker triad consisting of three screws was fixed to the first cuneiform and the second metatarsal. A digitizer was utilized to record the three-dimensional positions of the registration markers and their displacement in test conditions before and after cutting of the Lisfranc ligament and after stabilization of the joint with either a suture button or a cannulated screw. The first and second cuneiforms and their metatarsals were removed, and the ligament attachment sites were digitized. Displacement at the Lisfranc ligament and the three-dimensional positions of the bones were determined. Loading with the Lisfranc ligament cut resulted in displacement that was significantly different from that after screw fixation (p = 0.0001), with a difference between means of 1.2 mm. Likewise, loading with the Lisfranc ligament cut resulted in a displacement that was significantly different from that after suture-button fixation (p = 0.0008), with a difference between means of 1.00 mm. No significant difference in displacement was found between specimens fixed with the suture button and those fixed with the screw. Suture-button fixation can provide stability similar to that provided by screw fixation in cadaver specimens after isolated transection of the Lisfranc ligament.