Preparation of a gear distraction plate device for spinal reduction and fixation / 中国组织工程研究

ABSTRACT

BACKGROUND: The most commonly used rod-screw posterior spinal fixation system has some biomechanical drawbacks. The screw-plate system is more preferred for patients.OBJECTIVE: To prepare a new posterior spinal fixation system based on imaging results of distance between two pedicles,radian of spine flexion, extension and the height of intervertebral space of Chinese population.METHODS: The thoracolumbar data of 129 normal people were measured. According to the imaging measurements and relative documents, a device of gear-distraction plate (GDP) for spine reduction and fixation was designed. Eighteen fresh calf lumbar specimens were randomly divided into 3 groups, the test group was fixed by GDP and the other groups were fixed by CD and Steffee plate, respectively. The results of the displacement, strain, strength, stiffness and ultimate strength were measured under the states of vertical compression, flexion, extension and lateral bending respectively, and the results were statistically analyzed.RESULTS AND CONCLUSION: GDP could meet the need of strength and stiffness of human bodies. It showed superior to the CD and Steffee plate groups in strength and stiffness (P ＜ 0.05), with 13% or 14% torsion intensity greater than that of the CD or Steffee plate groups. The ultimate mechanical performance test showed that, the load bearing of the GDP group was greater than that of the CD and Steffee plate groups (P ＜ 0.05). The findings demonstrated that GDP for Chinese human presented with good biomechanical stability, which can promote vertebrae fracture union and prevent kyphosis relapses or vertebral height loses.