正常人T4～T12肋骨头与相应椎体椎管解剖学及影像学研究

Anatomic and radiographic study of the rib head associated with spinal canal and vertebral body in adult

目的:观察正常人肋骨头和相应椎体及椎管的解剖学及影像学关系。方法:解剖测量组(A组),解剖10具正常成人尸体脊柱标本,测量各节段肋骨头对椎体遮挡率(即双侧肋骨头前缘连线到椎管前壁距离与椎体前缘到椎管前缘距离百分比),以及胸椎前路置钉时最大前方安全角度以及最大后方安全角度(最大前方安全角度即以肋骨头为参照物前路牢固置入螺钉时可向椎体前方形成的最大夹角;最大后方安全角度即以肋骨头为参照物置入螺钉时螺钉不进入椎管可向椎体后方形成的最大夹角);影像测量组(B组),测量30例健康成人胸椎CT平扫片,测量CT照片上各节段肋骨头对相应椎体遮挡率、胸椎前路置钉时最大前方安全角度以及最大后方安全角度。结果:两组肋骨头对相应椎体遮挡率自上而下逐渐减小(从T4约30%到T12约-0.4%),越往头侧肋骨头相对于椎体越靠前,越往下胸椎肋骨头定位相对靠后;前方最大安全角度渐增加(T4约27°到T12约38.3°,P<0.05),后方安全角度逐渐减小(T4约23°到T12约-9°,P<0.05),A、B组间比较统计学差异无显著性(P>0.05)。结论:术前CT片的测量肋骨头和相应椎体椎管的关系可指导胸腔镜辅助下胸椎前路手术置钉,在上段胸椎椎体前路置入螺钉时可考虑部分去除肋骨头,在下段胸椎前路置入螺钉时在肋骨头前缘可安全置入螺钉。

Objective：To investigate the anatomic and radiographic relationship between rib head and spinal canal or vertebral body in normal adult.Method：Ten normal adult cadavers（anatomic group,A） underwent thoracic CT scan.The rib head with respect to the spinal canal and vertebral body,and the ratio of vertebral body covered by rib head（defined by ratio of distance from bilateral anterior rib head to anterior wall of spine canal on the distance from anterior part of vertebra body to anterior wall of spine canal）,and the orientation angle when placing anterior screw were measured.CT scan on 30 healthy adults（radiographic group,B） was performed.The above-mentioned parameters were measured and compared with group A.Result：The ratio of vertebral body covered by rib head decreased significantly from T4 to T12.The rib head was sited more anteriorly with respect to the more cephalad vertebral body,while more posteriorly with respect to the more caudal vertebral body.The anterior maximum safe angle increased significantly from T4（27°） to T12（38.3°） and the posterior safe angle decreased significantly from T4（23°） to T12（-9°）,however no significant difference between anatomical group and the radiographic group was noted.Conclusion：Preoperative CT scan can show the relationship between the rib head and vertebral body,which may guide screw placing under VATS.Removal of rib head when placing screws in upper thoracic vertebra and removal of anterior part of rib head in lower thoracic vertebra can promise accuracy of instrumentation.