摘要
目的评估横连位置及数目对椎弓根皮质劈裂下脊柱内固定稳定性的影响。方法选用新鲜绵羊胸腰椎标本(T13~L3节段)60具,建立L1椎体压缩骨折模型,采用抽签法随机分为A、B、C、D、E、F 6组,每组10具。于T14、L2双侧椎弓根置入螺钉,连接钛棒固定T14~L2节段,然后切除B、C、D、E、F组T14椎体右侧椎弓根外侧1/4的骨皮质,作为椎弓根皮质劈裂椎体骨折模型。最后各组采用不同的横连数目固定:A组:0个横连;B组:0个横连;C组:1个横连,连接棒1/2处;D组:1个横连,连接棒1/3处,靠近T14椎体;E组:1个横连,连接棒2/3处,远离T14椎体;F组:2个横连,连接棒1/3和2/3处。各组标本在生物力学实验机上进行10 000次疲劳试验后,分别测量轴向压缩刚度,屈伸、侧弯、旋转6个方向的活动范围(ROM)及T14椎体椎弓根劈裂侧螺钉最大拔出力大小。结果 A、C、D、E、F组模型刚度均明显高于B组(P均<0.05),A组明显高于F组(P<0.05)。A、C、D、E、F组模型螺钉最大拔出力均明显高于B组(P均<0.05);A组明显高于F组,C、D、E组均明显小于F组(P均<0.05)。A、C、D、E、F组模型在屈伸、侧弯、旋转6个方向的运动范围均明显小于B组(P均=0.000),C、D、E组在旋转2个方向的运动范围明显大于F组(P均=0.000)。结论椎弓根固定劈裂时,放置1个横连就可以提高内固定的稳定性,放置2个横连可近似达到椎弓根固定未劈裂时的稳定性。横连位置在短节段固定脊柱固定差异无统计学意义。
Objective To evaluate the effect of transverse position and numbers on the stability of the spinal pedicle screw fixation during the pedicle cortex perforation. Methods The vertebral compression fracture was performed in the L1 vertebral body using the Chiba＇s method from 60 fresh thoracic and lumbar vertebrae samples of sheep（T13-L3）,which were randomly divided into 6 groups（A,B,C,D,E,and F） using a lottery method. Bilateral pedicles of vertebral arch of T14 and L2 were inserted pedicle screws,connecting titanium rods to fix T14-L2 segments. Then the samples of groups B,C,D,E,and F were removed a quarter ofright side of lateral T14 thoracic pedicle cortical,which were considered the pedicle cortex perforation model. Finally,each group was fixed on different numbers of crosslinks： group A（0 crosslink,Intact）,group B（0crosslink,NCL）,group C（1 crosslink,1/2 of the rods, MCL）, group D（1 crosslink,1/3 of the rods close to T14, PCL）, group E（1 crosslink,2/3 of the rods away from T14, DCL） and group F（2crosslinks,1/3 and 2/3 of the rods respectively,TCL）. After all samples were subject to 10 000 times of fatigue test with biomechanics test machines,the axial compressive stiffness,range of the motion（ROM） of the6 directions（flexion,extension,lateral bending,and axial rotation）,and the maximum pullout of the screws of the T14 pedicle cortex perforation were measured and compared among these 6 groups. Results The axial compressive stiffness in groups A,C,D,E,and F was significantly higher than that in group B（all P〈0. 05）,and group A was significantly higher than group F（P〈0. 05）. The maximum pullout in groups A,C,D,E,and F were significantly higher than that in group B（all P〈0. 05）,and group A was significantly higher than group F and groups C,D,and E were significantly lower than group F（all P〈0. 05）. ROM of flexion,extension,lateral bending,and axial rotation in groups A,B,C,D,E,and F were significantly lower than that in group B（P = 0. 000）,and ROM of left and right axial rotation in groups C,D,and E were significantly higher than in that group F（P = 0. 000）. Conclusions During the pedicle cortex perforation,adding of one crosslink can improve the stability of the pedicle cortex perforation,and adding of two crosslinks can approximately achieve the same stability as the pedicle screw fixation with no pedicle cortex perforation. The location of the crosslink has no obvious effect on the short segment of spinal fixation.
出处
《中国医学科学院学报》
CAS
CSCD
北大核心
2017年第3期365-370,共6页
Acta Academiae Medicinae Sinicae
基金
河北省省级重大医学科研课题(zd2013050)~~
关键词
椎体骨折
短节段
横连
椎弓根皮质劈裂
脊柱稳定性
vertebral fractures
short-segment
crosslinks
pedicle cortex perforation
spinal stability
