Effect of Dome-Shaped Titanium Mesh Cages on Cervical Endplate Under Cyclic Loading: An In Vitro Biomechanics Study

BACKGROUND This study aimed to verify the anti-subsidence ability of dome-shaped titanium mesh cage (TMC) used in anterior cervical corpectomy and fusion (ACCF). MATERIAL AND METHODS Thirty fresh human cervical vertebrae specimens were collected and randomly harvested into 2 groups: the traditional TMC group and the dome-shaped TMC group. The bone mineral density (BMD) of the specimens was recorded. Each group was biomechanically tested in axial compression with a cyclically loading range from 60 to 300 N at 0.5Hz for 10 000 cycles. The displacement data of the 2 groups were recorded every 10 cycles. RESULTS There was no significant difference in bone mineral density between the 2 groups of cervical specimens. The traditional TMC group stabilized at 535±35 cycles while the dome-shaped TMC group stabilized at 1203±57 cycles, which showed that the rate of subsidence of the dome-shaped TMC group was significantly slower than that of the traditional TMC group (p<0.05). After reaching stability, both groups had a more gradual and sustained growth. The peak displacement during fatigue testing was -2.064±0.150mm in the traditional TMC group and -0.934±0.086mm in the dome-shaped TMC group, which showed a significant difference (p<0.05). CONCLUSIONS The dome-shaped TMC showed a smaller subsidence displacement and a gentler subsidence tendency following the same cyclic loading (compared to the traditional TMC). From a biomechanical point of view, the dome-shaped TMC has stronger anti-subsidence ability due to its unique structural design that closely matches the vertebral endplate.