title: A biomechanical analysis of a tensioned suture device in the fixation of the ligamentous Lisfranc injury.
abstract: BACKGROUND
  We hypothesized that using a cadaveric Lisfranc ligamentous injury model, abduction stress would provoke greater post-injury motion than axial weightbearing between the medial cuneiform (MC1) and the base of the second metatarsal (MT2). Second, we hypothesized that both a tensioned suture-button device and a rigid screw fixation method could maintain a reduction and similarly restrain motion to intact (pre-injury) levels.
  
  
  METHODS
  Motion was measured between MC1 and MT2 in five matched pairs of human cadaveric feet. Specimens were tested prior to injury, following a transverse ligamentous Lisfranc injury, and then randomized to either screw or tensioned suture-button fixation. Axial then abduction loads were applied. Measurements were repeated after one thousand loading cycles.
  
  
  RESULTS
  With both axial and abduction loads, statistically significant differences in motion were detected between the intact and post-injury conditions, although the magnitudes were greater with abduction (6.8 mm versus 2.0 mm, p = 0.000004). With abduction loads, both fixation methods were effective in restraining motion to pre-injury levels (screw fixation: 1.5 mm intact versus 1.1 mm post-fixation, p = 0.487; suture-button fixation: 1.3 mm intact versus 2.1 mm post-fixation, p = 0.063), and similarly, both devices restrained motion to less than post-injury levels (screw fixation: 8.1 mm post-injury versus 1.1 mm post-fixation, p = 0.001; suture-button fixation: mean 5.5 mm post-injury versus 2.1 mm post-fixation, p = 0.0002). No significant differences in these patterns were detected following cyclic loading.
  
  
  CONCLUSIONS
  Small, though statistically significant, amounts of motion are produced between MC1 and MT2 with axial loading after a ligamentous Lisfranc injury. With abduction stress, we were able to show a significantly greater difference between pre- and post-injury motion and the ability of both fixation methods to restrain motion to pre-injury levels.
  
  
  CONCLUSIONS
  Abduction stress may be valuable when diagnosing and testing the transverse ligamentous Lisfranc injury. Both suture-button and screw fixation methods restrain motion at the Lisfranc complex.
authors: University Orthopaedic Center, Salt Lake City, UT 84108, USA.
authors: Christopher E
authors: CE
authors: Pelt
authors: Kent N
authors: KN
authors: Bachus
authors: Richard E
authors: RE
authors: Vance
authors: Timothy C
authors: TC
authors: Beals
mesh_terms: D001696:Biomechanical Phenomena; D005260:Female; D005528:Foot / Q000601:surgery*; D018409:Foot Injuries / Q000601:surgery*; D006801:Humans; D016268:Internal Fixators; D008022:Ligaments / Q000293:injuries* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D013536:Suture Techniques