Cage椎弓根内固定联合自体颗粒骨打压植骨的即时生物力学稳定性

Clinical application of pedicle screw fixation with autogenous morselized bone graft impaction in senile lumbar degeneration:A study of immediate biomechanical stability

背景:自体骨移植结合椎间融合器联合椎弓根螺钉常运用于椎体融合,但单纯颗粒骨打压联合椎弓根钉的临床生物力学研究报道不多。目的:比较后路自体颗粒骨打压植骨内固定及Cage内固定的即时生物力学稳定性。方法:利用腰椎后路附件逐级破坏和椎间盘切除制作腰椎不稳模型。12具猪腰椎标本随机分为两组:打压植骨结合椎弓根螺钉内固定组(实验组),Cage结合椎弓根螺钉内固定组(对照组)。使用脊柱三维运动测试机模拟人体对两组标本在正常、不稳、融合3个状态下进行前屈、后伸、左右侧屈、左右旋转等各个活动的生物力学测试,三维激光扫描仪测定不同载荷下不稳节段的运动范围。结果与结论:正常状态下,两组间L2～3节段各方向运动范围差异无显著性意义(P>0.05),说明两组标本均衡性好,具有可比性;与正常状态相比,两组不稳状态各方向运动范围亦明显增加(P<0.05);融合后对照组L2～3节段椎间各方向运动范围均较实验组小,但差异无显著性意义(P>0.05)。说明自体颗粒骨打压植骨内固定与Cage内固定均能明显提高脊柱的即时生物力学稳定性,而且两组对于改善脊柱稳定性无显著性差异。

BACKGROUND：Autogenous bone graft combined with cage has been widely used in lumbar interbody fusion by the use of vertebral pedicle screw fixation.But there is still lack of reports about autogenous morselized bone graft impaction with vertebral pedicle screw fixation concerning the clinical application and biomechanical research.OBJECTIVE：To evaluate and compare the biomechanical stability properties of autogenous morselized bone graft impaction with vertebral pedicle screw fixation,cage with vertebral pedicle screw fixation,so as to provide theoretical basis and experiment guidance in clinical use of autogenous morselized bone graft impaction with vertebral pedicle screw fixation in PLIF.METHODS：Resin embedding method and graded facetectomy and discectomy were made to prepare spinal instability models.Experimental group used autogenous morselized bone graft impaction with vertebral pedicle screw fixation;control group used cage with vertebral pedicle screw fixation.The three-dimensional motion of specimens was tested in intacted state,instability state and fusion state,which the flexion,extension,bilateral bending and axial rotation loading were applied to the specimens and the range of motion（ROM） were determined by the three-dimensional laser scanner.RESULTS AND CONCLUSION：There was no significant difference in all stability indexes（ROM） between two groups in intact state（P 0.05）.Compared with the intact state,there was significant difference in all stability indexes in instable state between the two groups.After posterior lumbar interbody fusion,there was no significant difference in all stability indexes between two groups（P 0.05）.Both the autogenous morselized bone graft impaction with vertebral pedicle screw fixation and cage with vertebral pedicle screw fixation can improve the immediate biomechanical stability of the spine,and there is no statistical difference in spinal stability capacity between two groups.