The effect of multiple‐level total laminectomies followed by stabilization on the load‐deformation behavior of the cervical spine is described. Fresh human ligamentous cervical spines (C2‐T2) were potted and clinically relevant load types applied via a loading frame attached to the C‐2 vertebra of the specimen. A set of three infrared light‐emitting diodes (LEDs) were attached rigidly to each of five vertebrae (C3‐7) to record their spatial locations after each load step application, using a Selspot II system. The specimen was tested again after total laminectomy performed on C5. The supraspinous, interspinous, and flavum ligaments between the C4‐5 and C5‐6 motion segments were cut; thereafter, the vertebral arch was removed. The specimen testing was resumed after inducing injury at C‐6 in a similar fashion. The specimen was stabilized, using a facet wiring construct, across the C4‐7 segment before testing for the final time. The load‐deformation data of the injured and stabilized tests were normalized with regard to the corresponding results of the intact test. In flexion‐extension mode, an increase in motion of about 10% after laminectomies was observed. Facet wiring was found to be an effective technique to stabilize injured cervical spines (≈80% reduction in motion, compared with intact spines, was observed).
Keywords:
Biomechanics; Cervical spine; Stabilization; Laminectomy