Biomechanical Evaluation of Calcaneocuboid Distraction Arthrodesis: A Cadaver Study of Two Different Fixation Methods

Abstract

Calcaneocuboid distraction arthrodesis can be used to treat stage 2 posterior tibial tendon dysfunction. Nonunion, graft resorption, and implant failure have been reported after this procedure. This study compared two of the most commonly used methods for fixation of calcaneocuboid distraction arthrodesis. Twelve pairs of cadaver feet underwent simulated calcaneocuboid distraction arthrodesis. One specimen in each pair was fixed with two crossed 3.5 mm cortical lag screws. The contralateral specimen was fixed with a cervical H-plate. The calcaneus was fixed and a load was applied to the plantar aspect of the cuboid at a rate of 5 mm/minute until joint separation of 3 mm or fracture occurred. The average applied load to failure at 1.0 mm of joint separation was 30.5 +/- 11.6 N for the crossed screws and 77.7 +/- 36.4 N for the cervical H-plate (p = 0.001). The average stiffness at 1.0 mm of joint separation was 27.5 +/- 10.9 N/mm for the crossed screws and 43 +/- 21.2 N/mm for the cervical H-plate (p = 0.036). The higher stiffness and load to failure may account for the decreased nonunion rate noted anecdotally by some surgeons with H-plate fixation over crossed screw fixation for calcaneocuboid distraction arthrodesis.

Biomechanical In Vitro - Stability Testing on Human Specimens of a Locking Plate System Against Conventional Screw Fixation of a Proximal First Metatarsal Lateral Displacement Osteotomy

“…A complex plantar dissection necessary to improve the stability by a plantar plate placement [26] was not necessary. Test models described in literature often use feet disarticulated in the ankle, arranged in an unphysiological position, measuring only translational forces or rely on synthetic bone [25, 27-29]. In some studies the locking plate lacked the possibility of interfragmentary compression and three - dimensional aspects were not taken into consideration in contrast to our study [30, 31].…”

Acquired Flat Foot Deformity: Postoperative Imaging

“…Use of a cervical H-plate has a much lower reported incidence of nonunion in comparison with crossed screws for graft fixation. 58 Nonunion may be demonstrated on x-ray. CT provides a more accurate assessment for nonunion or hardware loosening.…”