A Biomechanical Study Using Cadaveric Toes to Test the Stability of Fixation Techniques Employed in Arthrodesis of the First Metatarsophalangeal Joint

Abstract

Arthrodesis of the first metatarsophalangeal joint of 15 pairs of cadaveric big toes were performed. The arthrodesis site was shaped with either a dome and socket or planar surface contact between the metatarsal head and proximal phalanx. A template was used to standardize the position of arthrodesis in 20° of valgus and 20° dorsiflexion. Various fixation devices were used to hold this position in corresponding pairs of specimens, and these fixation devices were tested to determine their relative effectiveness to prevent displacement on loading. Force-deflection curves were obtained for the various techniques tested, and by comparing these curves, the stability of the metatarsophalangeal arthrodesis site was found to be maintained most effectively using the cancellous screw fixation device with planar metatarsophalangeal surfaces.