胸椎椎弓根-肋骨复合体螺钉置入内固定的应用解剖学特征

Anatomic characteristics of thoracic pedicle-rib complex for internal fixation

背景:上、中胸椎周围结构复杂,椎弓根的横径相对窄小,如再合并发育畸形,导致螺钉不能置入,或者置入后造成副损伤,置钉安全性和有效性得不到保证。目的:提出"椎弓根-肋骨复合体"的概念,观察其形态结构,分析其在解剖学上置入螺钉的可行性。方法:观察6具成人尸体胸椎标本(T1～12)椎弓根及椎弓根-肋骨复合体的形态结构,测量下列参数:横径、纵径、椎弓根-肋骨复合体轴线螺钉置入最长值、椎弓根-肋骨复合体轴线螺钉横断面角及椎弓根-肋骨复合体轴线螺钉与椎弓板的夹角。结果与结论:椎弓根-肋骨复合体是一立体结构,椎弓根与肋骨不在同一平面,且两者位置关系随不同节段而发生变化。横径为13.0～17.3mm,纵径为5.8～8.0mm,椎弓根-肋骨复合体轴线螺钉置入最长值为43.4～60.5mm,椎弓根-肋骨复合体轴线螺钉横断面角为15.4°～36.7°,椎弓根-肋骨复合体轴线螺钉与椎弓板的夹角为76.2°～85.4°。提示沿胸椎经椎弓根-肋骨复合体轴线置入螺钉内固定时,安全范围较大。应用于临床时,可作为椎弓根螺钉内固定的一种补充,特别是在无法完成椎弓根螺钉置入的胸椎平面。

BACKGROUND：The surrounding structures of the thoracic vertebra are complicated,and the thoracic pedicle is thinner than lumbar pedicle anatomically,particularly in some cases of scoliosis or other spine deformity,resulting in impossible implantation of pedicle screws or post-implantation injury.Therefore,the safety and efficacy of pedicle screw fixation cannot be guaranteed.OBJECTIVE：To study the applied anatomy of the pedicle-rib complex and to perform the biomechanical test for screw insertion through the pedicle-rib complex in the thoracic spine.METHODS：Six specimens of adult cadaveric thoracic spine（T1-12） were used to observe modality of pedicle and pedicle-rib complex.The following parameters were measured：pedicle width（P-W）,pedicle height（P-H）,pedicle length（P-L）,pedicle transverse angle（P-TA）,pedicle sagittal angle（PSA）,pedicle-rib complex transverse distance（PRC-W）,longitudinal distance（PRC-H）,screw length（PRC-L）,angle in transverse plane（PRC-TA） and angle in sagittal plane（PRC-SA）.RESULTS AND CONCLUSION：The measurement results of the above-mentioned parameters were as follows：PRC-W：13.0-17.3 mm,PRC-H：5.8-8.0 mm,PRC-L：43.4-60.5 mm,PRC-TA：15.4°-36.7°,PRC-SA：76.2°-85.4°.Screw implantation through the pedicle-rib complex in the thoracic spine is safer and has better mechanical stability than that of pedicle screw.The former one may be just regarded as a supplementary of the latter in some instance that the transversal width of thoracic pedicle is too small to implant screw.