ABSTRACT

The displacement values of hemilaminectomy and total discectomised spine specimens were similar to studies in the literature. Biomechanical instability has been achieved in a hemilaminectomy and total discectomy spine during extension and partial laminectomy side-bending movements. After a total discectomy, a reduction in annulus fibrosis tension caused laxity at the mobile spine segment. Increased mobilization caused instability at the spine mobile segment.

In axial compression test, compression test in flexion motion and the right bending position the specimens were more stable based on displacement values. The displacement values of hemilaminectomy discectomized spines were closer to the values of intact specimens. Comparing both groups, displacement values of extension and left-bending positions were significant (p≤0.05).

Ten fresh-frozen lamb spines were used in this study. Hemilaminectomy and discectomy was performed on each spine at L4-L5 level on the left side. The biomechanical tests for both intact spine and discectomy performed spine were performed by using axial compression testing machine. The axial compression was applied to all specimens with a loading speed of 5 mm/min. 8400 N/mm moment was applied to each specimen to achieve flexion and extension motions, right and left bending through a specially designed device.

This study aims to investigate the effects of hemilaminectomy and discectomy on the lumbar spine of the lamb by biomechanically comparing changes on motion segments between intact and hemilaminectomy discectomy performed.