History of instrumentation for stabilization of the subaxial cervical spine.

In the past several decades methods have been developed to stabilize the subaxial cervical spine both posteriorly and anteriorly. Methods of posterior stabilization have progressed from interspinous wiring, through facet wiring and sublaminar wiring, to the lateral mass screws with plates and rods that are in use today. Plates for anterior stabilization have evolved from rigid plates requiring bicortical screws through those used with unicortical locking screws, to dynamic load-sharing plates used with variable angle screws. The original description of spinous process wiring was published by Hadra in 1891. In 1942 Rogers described the interspinous wiring method used for trauma-induced cervical instability, which was modified by Bohlman in 1985 (triple wiring technique). Luque rods with sublaminar wires were introduced in the late 1970s to address multilevel and occipitocervical instability. Facet wiring was developed in 1977 by Callahan to address the problem of stabilization when laminae are not present. Wiring remained the method used until Roy-Camille introduced the lateral mass screw-plate construct in the 1980s. The first plate for anterior stabilization was designed by Orozco and Llovet in 1970 and was later refined by Caspar; this was a rigid plate with bicortical screws. Morscher devised unicortical locking screws in the 1980s. The latest concept of dynamic load-sharing plates with variable angle screws was developed in 2000. In this article historical landmarks in surgical methods for the stabilization of the subaxial cervical spine are reviewed.