Effect of different fusion types on kinematics of midfoot lateral column: a comparative biomechanical study

Background: This study aimed to compare the biomechanical outcomes of the isolated 4 th or 5 th tarsometatarsal (TMT) joint arthrodesis with the whole lateral TMT joints arthrodesis. Methods: Ten cadaveric lower legs underwent isolated 4 th TMT joint arthrodesis, 5 th TMT joint arthrodesis, and whole lateral TMT joints arthrodesis in sequence. Texson F-scan and K-scanTM joint sensor were used to test the medial and lateral plantar pressure and the pressure of calcaneocuboid joint. Results: Compared with the intact foot, the lateral forefoot pressure increased significantly (P th TMT joint fusion. The medial forefoot pressure was significantly lower in the 5 th TMT joint fusion than that in the intact foot (P th TMT joint fusion (P th TMT joint fusion than that in the intact foot and the 4 th TMT joint fusion, but lower than that in the whole lateral TMT joints fusion (P th TMT joint arthrodesis, the isolated 5 th TMT joint arthrodesis, and the whole lateral TMT joints arthrodesis (P Conclusions: The isolated 4 th or 5 th TMT joint arthrodesis has less impact on the pressure of forefoot and adjacent joints than the whole lateral TMT joints arthrodesis. The isolated 4 th TMT joint arthrodesis has the lowest influence on the pressure of forefoot and adjacent joints.