国人颈椎椎间盘解剖参数与常用人工椎间盘尺寸的比较

目的　分析临床上常用的人工椎间盘尺寸是否与国人颈椎椎体解剖尺寸相匹配,并据此提出适合国人的人工颈椎椎间盘设计方案。方法利用CT测量138例国内患者C_(2～7)椎体的相关解剖学数据(椎体终板前后径、横径,椎间隙高度,矢状角大小),并分别与4种常用人工椎间盘(Bryan、Prestige LP、Discover、Prodisc-C)的尺寸进行比较,分析人工椎间盘的尺寸是否与各个椎间隙尺寸相匹配,并计算不匹配率。结果 4种常用人工椎间盘中,在椎体终板前后径上与国人颈椎椎体解剖尺寸的不匹配率为15.22%(C_3/C_4节段,Prestige LP、Prodisc-C)至57.61%(C_6/C_7节段,Discover);在横径上的不匹配率为24.28%(C_3/C_4节段,Prodisc-C、Prestige LP)至94.93%(C_6/C_7节段,Bryan)。所有患者中,19.71%的椎体终板前后径大于最大人工椎间盘,52.17%的椎体终板最大横径大于最大人工椎间盘。除了因高度不固定而无法比较的Bryan人工椎间盘,其他人工椎间盘的最大高度均满足患者各节段的最大椎间隙高度,但39.13%的颈椎椎间隙高度小于最小的人工椎间盘高度。C_2/C_3、C_3/C_4、C_4/C_5、C_5/C_6、C_6/C_7节段平均矢状角分别为3.64°、4.51°、5.04°、5.15°、4.13°,纳入的4种人工椎间盘中只有Discover有固定的7°前凸角与之相符。结论目前临床上常用的人工椎间盘尺寸与国人椎体解剖数据存在较大差异,应设计更多的人工椎间盘尺寸来匹配国人颈椎。

Comparison of anatomical parameters of cervical intervertebral disc in Chinese and size of commonly used artificial intervertebral disc

Objective To analyze whether the size of artificial cervical intervertebral disc commonly used in clinic matches the anatomical size of Chinese cervical vertebrae for putting forward a design scheme of artificial cervical intervertebral disc suitable for Chinese people. Methods Relevant anatomical data of C_2-7 vertebral bodies(anterior and posterior diameters and transverse diameter of the vertebral endplate,height of intervertebral space,sagittal angle) were measured by CT in 138 domestic patients,and compared with artificial intervertebral discs(Bryan,Prestige LP,Discover,Prodisc-C),and the mathche between the size of artificial intervertebral disc and the size of each intervertebral space was analyzed,and the mismatch rate was calculated. Results The mismatch rate of available dimensions of prostheses and anatomic data of cervical endplates ranged from 15.22%(C₃/C₄ segment,Prestige LP,Prodisc-C) to 57.61%(C₆/C₇ segment,Discover) in the anterior-posterior diameter,and 24.28%(C₃/C₄ segment,Prodisc-C,Prestige LP) to 94.93%(C₆/C₇ segment,Bryan) in the center mediolateral diameter. In all the patients,19.71% endplates were larger than the largest prostheses in the anterior-posterior diameter,and 52.17% in the center mediolateral diameter. Except for Bryan with an unfixed height,the maximum height of other artificial intervertebral discs satisfied the maximum intervertebral space height of each segment,but 39.13% of the intervertebral space height was less than the minimum artificial intervertebral disc height. The average sagittal angles of C₂/C₃,C₃/C₄,C₄/C₅,C₅/C₆,and C₆/C₇ segments were 3.64°,4.51°,5.04°,5.15°,and 4.13° respectively. Only the Discover brand had a built in 7° lordotic angle matching with the disc sagittal angle roughly. Conclusion There is a large discrepancy between size of artificial intervertebral disc and Chinese cervical anatomic data. More artificial intervertebral disc sizes should be designed to match Chinese cervical vertebra.