Mechanical behavior of the Lisfranc and dorsal cuneometatarsal ligaments: In vitro biomechanical study

Objectives: To define the anatomy and mechanical properties of two ligament s stabilizing the medial tarsometatarsal joints: the Lisfranc ligament and the dorsal cuneometatarsal ligament. Design: Cadaveric study in normal feet. Setting: Biomechanics laboratory. Patients or Participants: Twelve fresh-frozen cadaveric feet were studied. Intervention: The Lisfranc and dorsal cuneometatarsal ligaments were dissec ted, dimensions measured, and material properties determined with a servohy draulic MTS machine on bone-ligament-hone preparations. Main Outcome Measurements: Stiffness, strain, stress, modulus, failure load , ligament length, width, thickness, and cross-sectional area were determin ed. Results: Dorsal ligament stiffness was 66.3 +/- 18.3 newtons per millimeter and the Lisfranc ligament stiffness was 189.7 +/- 57.2 newtons per millime ter. The failure load of the dorsal ligament averaged 150.7 +/- 33.1 newton s and for the Lisfranc ligament, 368.8 +/- 126.8 newtons. Conclusions: The stiffness and load to failure of the dorsal cuneometatarsa l ligament were much higher than anticipated, which indicates that it contr ibutes significantly to stabilizing the second metatarsal to the first cune iform.