摘要
目的:比较胸椎经“椎弓根-肋骨间”螺钉与椎弓根螺钉固定的抗拔出力。方法:5例新鲜尸体脊柱(T6～T10)标本,自椎间盘、小关节及上位椎体下肋椎关节处分解为单椎体(附带双侧肋骨)25个。根据配对随机分组的原则,随机选取椎体一侧作椎弓根螺钉固定组,另一侧则为配对的“椎弓根-肋骨间”螺钉固定组,共组成25个配对组。同组中“椎弓根-肋骨间”螺钉长度较椎弓根螺钉长10mm,直径与椎弓根螺钉相同。将25组的50个螺钉分别进行拔出测试(5mm/min的速度垂直方向拔出)。结果:“椎弓根-肋骨间”螺钉的抗拔出力为423.1±198.7N;椎弓根螺钉的抗拔出力为783.3±199.5N。前者的抗拔出力显著小于后者(P<0.01)。结论:“椎弓根-肋骨间”螺钉的力学性能不及椎弓根螺钉,建议仅将前者作为后者的一种补充,特别是在无法完成椎弓根螺钉置入的部分胸椎节段。
Objective：In vitro biomechanical pullout testing was performed to evaluate the axial pull-out strength of pedicle rib unit screws versus pedicle screws in the thoracic spine.Method：Five fresh human cadaveric thoracic spines （T6-T10） were harvested and disarticulated into 25 vertebra rib units from the following lever：intervertebral disk,facet articulation and inferior costovertebral articulations.according to the principle of paired grouping,one side of each vertebra was prepared for pedicle screw randomly,and the other side,of course,was regarded as pedicle rib unit （the proximate ribs of both sides have been preserved until grouping finished）.The diameter of pared screw was the same in each group,but the length of pedicle rib unit side screw was 10 mm longer than that of pedicle side. 25 pared groups were obtained and the axial pull-out strength of 50 screws was measured respectively,in addition,the velocity of the axial force was 5mm/min.Resuit：The axial pull-out strength of pedicle rib unit screws was 423.1±198.7N,which was smaller significantly（P〈 0.01） than that of pedicle screws（783.3±199.5N）.Conclusion：The pull-out strength of pedicle rib unit screw is in inferior position compared with the pedicle screw,so the former may be just regarded as a supplementary of the latter,especially for some thoracic segments which transversal width of pediele is too narrow to screw.
出处
《中国脊柱脊髓杂志》
CAS
CSCD
2006年第8期623-625,共3页
Chinese Journal of Spine and Spinal Cord
