Subaxial Posterior Instrumentation

KEY FACTS

Terminology

• Methods to stabilize subaxial cervical spine with posterior element constructs

Procedure

• Interspinous wiring (Rogers 1942)

  • Simple and low risk

• Sublaminar wiring

  • Attach to onlay graft material or rods

• Facet wiring (Callahan 1977)

  • Facet capsules opened and holes drilled at each level

• Clamps (Tucker 1975)

  • Narrows spinal canal similar to sublaminar wires

• Lateral mass screws and plates (Roy-Camille)

  • Immediate stability with no need for external halo fixation

  • Usually oriented in superior and lateral direction to avoid VA and exiting nerve roots

• Transarticular screws

  • Used in C1-C2 interspace but also described for subaxial spine

• Lateral mass screws and rods

  • Very useful for multilevel disease

• Cervical pedicle screws (Abumi 1994)

  • Excellent stability and fixation

  • Resistant to pullout

  • Technically challenging since verterbal artery injury can occur

Outcomes

• Lateral mass screw: Incidence of facet joint violation as high as 20%

• Pedicle screw: 1.7% neurovascular complications

  • 7% cortical perforation rate for cervical pedicle screws

  • Pedicles should be at least 4.5 mm in diameter for safe screw placement

• Dural tear: Related to sublaminar wire placement