The Kinematics and Biomechanics for Non-Contiguous Anterior Cervical Discectomy and Fusion, Cervical Disc Arthroplasty, and Hybrid Cervical Surgery: A Systematic Review

Cervical disc degenerative disease (CDDD) is a common spinal pathology that is often treated with anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty (CDA), and/or hybrid cervical surgery (HCS). The purpose of this first-time systematic review is to examine the biomechanical outcomes associated with three types of non-contiguous cervical surgeries-ACDF, CDA, and HCS-to provide a greater understanding of non-contiguous cervical surgical biomechanics. A systematic review was performed using PubMed, Cumulated Index to Nursing and Allied Health Literature (CINAHL), MEDLINE, and Web of Science from database inception until June 6th, 2023. The inclusion criteria was any article that reported biomechanical or kinematic outcomes, outcomes for any of the three non-contiguous cervical surgeries, and human-derived and/or human cadaver subjects. A total of 5 biomechanical articles were included from a total of 523 articles. Non-contiguous two-level HCS experienced less drastic range-of-motion (ROM) changes throughout the cervical spine and decreased intervertebral disc pressure (IDP) compared to non-contiguous two-level ACDF. Non-contiguous two-level CDA resulted in more cervical ROM and less non-operative segment facet contact force compared to non-contiguous two level ACDF. There was less cephalad and caudal non-operative segment ROM in non-contiguous two-level ACDF compared to contiguous three-level ACDF.