与人工髓核置换相关的国人腰椎间盘结构测量

背景：临床多根据影像资料中腰椎间盘径线尺寸来选择假体型号和预计置入数量。 目的：以X射线片和MRI测量分析正常人腰椎间隙高度、腰椎间盘及髓核径线,获取与人工髓核假体相关的椎间盘基础数据。 方法：随机抽取157名正常成年人标准腰椎侧位X射线片,测量腰椎间隙前缘、中点和后缘高度。随机抽取106名正常成年人腰椎MRI片,测量椎间盘及髓核的横径和矢状径。 结果与结论：①X射线片：椎间隙自上而下逐渐增宽,腰椎间隙后高较低,近50%的L2/3、L3/4、L4/5椎间隙后高和约39.5%的L5/S1椎间隙后高位于7~9 mm区间。②MRI片：腰椎间盘横径和矢状径从L2/3至L5/S1依次增大。约46.7%的椎间盘矢状径大于37 mm,仅49.0%的髓核矢状径大于24 mm;本组髓核平均横径33.5 mm,平均矢状径23.4 mm。髓核矢状径均大于12 mm。约22.9%的髓核矢状径大于24 mm。提示多数国内患者需行单枚PDN假体置入,7 mm为最适用的PDN假体高度,临床不宜将椎间盘矢状径大于37 mm作为国人PDN假体置入数量的术前预评价指标。

Measurement of lumbar disc related to artificial nucleus pulposus replacement in Chinese

BACKGROUND: Surgeons usually predict the size and number of nucleus pulposus (NP) prosthesis before operation according to the diameters of lumbar intervertebral disc measured on medical images. OBJECTIVE: To measure and analyze height of lumbar intervertebral space, lumbar disc and NP diameters in normal for obtaining basic data of intervertebral disc related to artificial prosthetic nucleus. METHODS: Totally 157 lumbar spine X-ray films (Lateral views) of normal adult were randomly selected. Anterior, middle and posterior heights of lumbar intervertebral space were measured on X-ray films. A total of 106 lumbar Magnatic Resonance Imaging (MRI) images of normal adult were randomly selected for measuring transverse diameter and antero-posterior diameter (A-P diameter) of NP and lumbar disc. RESULTS AND CONCLUSION: ① X-ray film: from upper to lower, the height of intervertebral space increased gradually. Posterior height of lumbar intervertebral space was low. It ranged between 7 mm and 9 mm, approximately 50% at L2/3, L3/4, and L4/5, about 39.5% at L5/S1. ② MRI images: from L2/3 to L5/S1, the transverse diameter and A-P diameter of lumbar disc enlarged in turn. About 46.7% A-P diameter of lumbar discs were more than 37 mm. However, only 49.0% were proved that the A-P diameters of NP were more than 24 mm. In this study, the average transverse diameter of NP was 33.5 mm, the average A-P diameter was 23.4 mm. The A-P diameters of NP were all more than 12 mm. Among these, about 22.9% were more than 24 mm. The results indicated that single prosthetic disc nucleus (PDN) is suitable for most Chinese patients, and the height of 7 mm of PDN is commonly chosen. The A-P diameter of lumbar disc ranging from 37 mm is demonstrated unreliable to predict double PDN replacement before operation in Chinese.