IN VITRO TESTING OF POSTERIOR CERVICAL LATERAL MASS PLATING SYSTEMS: COMPARISON OF CONSTRAINED VERSUS SEMI-CONSTRAINED SCREW-SLOT CONNECTIONS

摘要

Interspinous or facet wiring has been the standard treatment for posterior cervical spine instability secondary to trauma or decompression (Wellmann et al., 1998). However, wire techniques may be limited when posterior elements are deficient or fractured. Alternative methods, such as posterior lateral mass plate fixation, may restore the stability of the affected region and promote fusion (Wellmann et al., 1998). The objective of the study was to determine if lateral mass plate fixation restored the stability of a reconstructed posterior destabilized cervical spine and to compare the biomechanical stability of two lateral mass plate designs: plates with screws constrained in slots (SCS) versus plates with screws unconstrained and free to translate in slots (SUS). Two posterior destabilized conditions were studied: a one-level (C4-C5) model and a two-level (C4-C6) model in which all posterior ligaments were sectioned.