Biomechanical experiments and strain analyses were performed to investigate the effects of lamina replacement surgery for intraspinal lesions on postoperative spinal stability. Eight specimens of thoracic and lumbar vertebrae (T12-L4) were collected from adult cadavers. Stepwise lumbar total laminectomy, and laminoplasty with lamina reduction and replacement was undertaken in combination with titanium-plate fixation to simulate the surgical setting. The effects of thoracic and lumbar vertebral strain, displacement, and rigidity on spinal stability were measured following both single and multiple segment laminectomy. Significant differences in mechanical indices of stability were seen between stepwise laminectomy of lumbar vertebrae and normal specimens (p < 0.05), between lamina replacement in combination with titanium-plate fixation and laminectomy (p < 0.05), and between single- and multiple-segment laminectomy (p < 0.05). Differences between laminoplasty with lamina replacement in combination with titanium-plate fixation and normal specimens need to be examined for further study. Lumbar laminectomy followed by reduction and replacement, in combination with titanium-plate fixation, was shown to be beneficial in terms of preserving spinal stability and maintaining biomechanical function and spinal loading capability.
Keywords: biomechanics; lamina replacement and titanium-plate fixation; spine; total laminectomy.