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

Objectives: To define the anatomy and mechanical properties of two ligaments 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 dissected, dimensions measured, and material properties determined with a servohydraulic 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 determined. Results: Dorsal ligament stiffness was 66.3 +/- 18.3 newtons per millimeter and the Lisfranc ligament stiffness was 189.7 +/- 57.2 newtons per millimeter. The failure load of the dorsal ligament averaged 150.7 +/- 33.1 newtons and for the Lisfranc ligament, 368.8 +/- 126.8 newtons. Conclusions: The stiffness and load to failure of the dorsal cuneometatarsal ligament were much higher than anticipated, which indicates that it contributes significantly to stabilizing the second metatarsal to the first cuneiform.