Biomechanical study of different fixation with hollow screws in spinal laminoplasty / 中国组织工程研究

ABSTRACT

BACKGROUND: Spinal lamina reimplantation assisted hollow screw laminoplasty has achieved good clinical efficacy. The search literature found that there is no research at home and abroad on the biomechanical properties of unilateral and bilateral hollow screw fixation. OBJECTIVE: To evaluate the biomechanical property of different fixation with hollow screws in artificial and goat vertebrate laminoplasty. METHODS: A laminoplasty was conducted by using hollow screws. Based on the artificial vertebrate laminoplasty model, new models were generated by simulating unilateral screws fixation with a depth of screw insertion 5 mm (A group), unilateral screw fixation with a depth of screw insertion 8 mm (B group) and bilateral screw fixation with a depth of screw insertion 5 mm (C group). Based on the goat vertebrate laminoplasty model, new models were generated by simulating unilateral screws fixation (A group) and bilateral screw fixation (B group). The pull-out strength and static pressure were tested in the biomechanical testing machine with a sensor. RESULTS AND CONCLUSION: (1) In the artificial vertebrate model, the average pull-out strength of the group B was stronger than that of the groups A and C (P < 0.01); the average pull-out strength of the group A was stronger than that of group C (P < 0.01), the difference was statistically significant (P < 0.05). However, the average static compression of the group A and group B was similar; the average static compression of the group C was lower than that of the groups A and B, and the difference was statistically significant (P < 0.01). (2) In the goat vertebrate model, the average pull-out strength and static compression of the group A were stronger than that of the group B, and the difference was statistically significant (P < 0.05). (3) Results suggest that unilateral screw fixation in the artificial and goat vertebrate laminoplasty can provide sufficient pull-out strength and static compression, and the biomechanical strength is positively related to the depth of the screw.