1～6岁正常小儿胸椎椎弓根形态学研究

Pedicle morphology of the immature thoracic spine in children aged 1 to 6 years

中文关键词:  胸椎  椎弓根  螺旋CT  断层影像解剖学  小儿

英文关键词:horacic vertebra  Pedicle  Spiral computed tomography  Sectional and imaging anatomy  Children

中文摘要:

  【摘要】 目的：测量1～6岁小儿胸椎椎弓根的形态学参数，为小儿胸椎椎弓根螺钉固定提供解剖学依据。方法：收集2009年7月~2010年1月在北京儿童医院行胸部CT检查的1～6岁非脊柱疾患小儿胸椎螺旋CT影像资料。根据年龄将入组儿童分为1～岁组（1组），2～岁组（2组），4～6岁组（3组），每组20例。每例均测量T1～T12左右两侧椎弓根参数共24组数值。将64排螺旋CT平扫胸椎的三维重建数据传至工作站，在多平面重建技术下获得每个椎弓根的矢状面及横断面成像，测量胸椎椎弓根横径（内外径）、纵径（内外径）、骨-螺钉通道长度、椎弓根横断面夹角、椎弓根矢状面夹角，并将上述各参数与年龄进行相关性分析，椎弓根横断面夹角和椎弓根矢状面夹角年龄组间采用多重T检验。结果：（1）椎弓根的横径（内外径）T1～T4逐渐减小，T5～T12逐渐增大；横内径值（除T1、T6、T11、T12外）与年龄无显著相关性（rs：0.011～0.363，除T1、T6、T11、T12外，P>0.05），其随年龄增长变化不明显；横外径值（除T4外）与年龄均存在显著正相关性（rs：0.151～0.539，除T4外，P<0.05），其随年龄增长而增长。（2）椎弓根纵径（内外径）T1～T12逐渐增大，除T1外纵径均大于横径；各节段参数与年龄均存在显著正相关性（纵内径rs：0.526～0.786，纵外径rs：0.692～0.864，P<0.05）。（3）骨-螺钉通道长度各年龄组中最短为T1或T2，最长为T9或T10，T1～T9有逐渐增加的趋势，T10～T12有逐渐减小的趋势；各节段参数与年龄均存在显著正相关性（rs：0.299～0.676，P<0.05）。（4）椎弓根横断面夹角最大为T1，T1～T12逐渐减小，部分小儿T11及T12的椎弓根横断面夹角可达0°甚至负角，除T1外，其余各节段参数与年龄均存在显著负相关性（rs：-0.432～-0.107，除T1 P>0.05外，余P<0.05），1组与2、3组间存在显著性差异（P<0.05），2组与3组间无显著性差异（P>0.05）。（5）椎弓根矢状面夹角T1~T12呈下降趋势，各节段参数与年龄无显著相关性（rs：-0.125～0.127，P>0.05），1、2、3三组间无显著性差异（P>0.05）。结论：1～6岁小儿胸椎椎弓根横外径、纵经、骨-螺钉通道长度与年龄的相关性较大，而椎弓根横内径的生长速度较慢，与年龄的相关性较小；横断面及矢状面夹角与年龄的相关性较小，除1~岁年龄组外，其余年龄段的参数值随年龄增长无明显变化。因此行1～6岁小儿胸椎椎弓根螺钉内固定手术时，应根据患儿年龄及术中情况妥善选择螺钉型号及进钉方式，以避免手术风险。

英文摘要:

  【Abstract】 Objectives: To quantify the morphometric characteristics of the pedicles of the immature thoracic spine（aged 1 to 6 years old）, and to provide morphologic basis pedicular screw instrumentation. Methods: A total of 60 patients without muscularskeletal disease and aged 1 to 6 years underwent standard spiral computed tomography of the chest in Beijing children′s hospital. The patients were grouped according to age: group 1(1-2 years old), group 2(2-3 years old) and group 3(4-6 years old), with 20 cases per group． For each case measurement was taken from pedicles on both sides from T1 to T12. Images were reconstructed by the 64 row helical CT and multiplanar reconstructions were used to attain images of thoracic pedicles on sagittal, coronal, and transverse planes. The measurements included the inner and outer pedicle diameters on both transverse and sagittal planes, the pedicle angle on both transverse and sagittal planes, and distance to anterior cortex. Their correlations with age were analyzed, inter-group comparisons of transverse pedicle angle(TPA)/sagittal pedicle angle(SPA) were analyzed using Multiple T test. Results: (1)Transverse pedicle diameters decreased gradually from Tl to T4, and then increased gradually from T5 to T12. The shortest transverse diameter of the thoracic pedicle located at T4 or T5. There was no correlation between the transverse pedicle inner diameter and age, except T1, T6, T11, T12(rs: 0.011-0.363, P>0.05, except T1, T6, T11, T12). The correlations between age and the transverse pedicle outer diameters were significant in all thoracic vertebra except T4(rs: 0.151-0.539, P<0.05, except T4). (2)Sagittal pedicle diameters increased from Tl to T12 and was significant longer than transverse diameter except T1. The correlations between age and sagittal pedicle diameters were significant in all thoracic vertebra(the inner rs: 0.526-0.786, the outer rs: 0.692-0.864, P<0.05). (3)The length from posterior cortex to anterior cortex of the vertebra increased from T1 to T10, decreased slightly from T10 to T12. The correlations between age and the length to anterior cortex were significant in all thoracic vertebrae(rs: 0.299-0.676, P<0.05). (4)The transverse pedicle angle decreased gradually from T1 to T12 though some cases did not show this trend. The correlations between age and TPA were significant in all thoracic vertebra except T1[rs: (-0.432)-(-0.107), P<0.05, except T1]. TPA in group 1 were significantly greater than group 2 and 3(P<0.05), there was no significant difference between group 2 and 3(P>0.05). (5)There was no significance with respect to the sagittal pedicle angles between three groups. There was no correlation between SPA and age[rs: (-0.125)-0.127, P>0.05]. There was no significant difference among three groups(P>0.05). Conclusions: The correlations between age and the transverse pedicle outer diameters, the sagittal pedicle diameters, distance to anterior cortex are significant in all thoracic vertebra of children aged 1-6 years. However, the transverse pedicle inner diameters increase slowly with age. There is no correlation between the transverse pedicle inner diameters and age nor between age and the pedicle angle on both the transverse and sagittal planes. The angular dimensions show little change due to vertebral growth except group 1. It is cautious to place thoracic pedicle screw in patients aged below 6 years in order to avoid high risks.