Comparing zero-profile and conventional cage and plate in anterior cervical discectomy and fusion using finite-element modeling

Conventional cage and plate (CCP) implants usually used in ACDF surgery, do have limitations such as the development of postoperative dysphagia, adjacent segment degeneration, and soft tissue injury. To reduce the risk of these complications, zero-profile stand-alone cage were developed. We used finite-element modeling to compare the total von Mises stress applied to the bone, disc, endplate, cage and screw when using CCP and ZPSC implants. A 3-dimensional FE (Finite element) analysis was performed to investigate the effects of the CCP implant and ZPSC on the C3 ~ T1 vertebrae. We confirmed that the maximum von Mises stress applied with ZPSC implants was more than 2 times greater in the endplate than that applied with CCP implants. The 3D analysis of the ZPSC model von Mises stress measurements of screw shows areas of higher stress in red. Although using ZPSC implants in ACDF reduces CCP implant-related sequalae such as dysphagia, we have shown that greater von Mises stress is applied to the endplate, and screw when using ZPSC implants. This may explain the higher subsidence rate associated with ZPSC implant use in ACDF. When selecting an implant in ACDF, surgeons should consider patient characteristics and the advantages and disadvantages of each implant type.