First Tarsometatarsal Joint Fusion in Foot—A Biomechanical Human Anatomical Specimen Analysis with Use of Low-Profile Nitinol Staples Acting as Continuous Compression Implants

Background and Objectives: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations comparison crossed screws locked plating a human anatomical model. Materials Methods: Thirty-two paired lower legs were randomized four groups for TMT-1 treatment via: (1) crossed-screws fixation 4.0 mm fully threaded lag screws; (2) plate-and-screw standard cortex screw, inserted axially fashion, 6-hole Variable-Angle (VA) Fusion Plate 2.4/2.7; (3) CCI two-leg placed orthogonally each other; (4) one staple four-leg other. Each specimen biomechanically tested simulating forefoot weightbearing on toes metatarsals. testing performed at 35–37 °C progressively increasing cyclic axial until construct failure, accompanied by motion tracking capturing movements joints. Results: Combined adduction dorsiflexion movement joint unloaded foot condition associated no significant differences among all pairs (p ≥ 0.128). In contrast, amplitude between loaded conditions within cycle significantly bigger techniques compared both ≤ 0.041). No detected techniques, well 0.493) parameter interest. Furthermore, displacements dorsal plantar aspects condition, together their amplitudes, did not differ 0.224). Conclusions: demonstrate comparable performance established applied joint.