Comparison of Locking Plate with Interfragmentary Screw Versus Plantarly Applied Anatomic Locking Plate for Lapidus Arthrodesis: A Biomechanical Cadaveric Study

Abstract

Arthrodesis of the first metatarsal cuneiform joint, or Lapidus procedure, is a widely accepted treatment for hallux valgus. Recent studies have focused on comparing various constructs for this procedure both in the laboratory and clinical settings. The current study compared in a cadaveric model the strength of 2 constructs. The first construct utilized a medially applied low-profile locking plate and an interfragmentary screw directed from plantar-distal to dorsal-proximal. The second construct consisted of a plantarly applied plate with a compression screw placed through the plate from plantar-distal to dorsal-proximal. The ultimate load to failure for the 2 groups tested was 255.38 ± 155.38 N and 197.48 ± 108.61 N, respectively (P = .402). There was no significant difference found between the 2 groups with respect to ultimate load to failure, stiffness of the construct, or moment at time of failure. In conclusion, the medially applied plate with plantar interfragmentary screw appears to be stronger than the plantar Lapidus plate tested for first metatarsal cuneiform arthrodesis, though this difference did not reach statistical significance. Levels of Evidence: Level V: Biomechanical Study