内蒙古地区枕骨髁及枕骨大孔应用解剖三维数字化测量

Three-dimensional digital measurement of occipital condyle and foramen magnum in Inner Mongolia

目的利用三维重建测量枕骨髁(OC)及枕骨大孔(FM)解剖学结构,分析OC、FM形态学特征及相对位置关系,为颅颈交界区病变的影像学诊断及外科手术入路的选择提供解剖学参数。方法选取60例正常者的头颅和上颈椎螺旋CT扫描图像,男、女各30例,年龄20~65(48.18±16.17)岁,将数据导入Syno.Via VB10B软件,头颅三维重建,观察OC及FM形态,测量枕骨髁长、宽、高、内倾角(CIA),枕骨大孔纵径、横径、面积,头颅眉间点到颅后点的最大距离(SML),在SML直线上头颅眉间点到枕骨髁后缘连线的距离(GOCP),枕骨大孔前缘到枕骨髁后缘连线的垂直距离(AOCP),左、右侧枕骨髁内侧缘到Y轴距离(OC-M),左、右侧枕骨髁后缘到X轴距离(OC-P),枕骨髁分类指数(OCI),枕骨髁相对于头颅的分类指数(SOCI),在SML直线上中点到枕骨髁后缘连线距离(COCP,COCP=GOCP-SML/2),并确定左、右枕骨髁相对位置关系的类型。结果枕骨髁解剖学长、宽、高男性大于女性,性别间差异有统计学意义(P<0.05);枕骨大孔面积、枕骨大孔纵径、SML、GOCP、AOCP性别间差异有统计学意义(P<0.05)。CIA左侧大于右侧,侧别差异有统计学意义(P<0.05)。OC-M、OC-P侧别差异有统计学意义(P<0.05),前者右侧大于左侧;后者左侧大于右侧。枕骨大孔纵径与枕骨大孔面积、AOCP成正相关。OCI分类结果:Ⅰ型(OCI<0.45)8例(13.33%),Ⅱ型(0.45≤OCI<0.50)47例(78.33%),Ⅲ型(OCI≥0.50)5例(8.33%)。SOCI分类结果:Ⅰ型(SOCI<0.60)2例(3.33%),Ⅱ型(0.60≤SOCI<0.75)54例(90.00%),Ⅲ型(SOCI≥0.75)4例(6.67%)。结论内蒙古地区人群枕骨髁解剖学参数提示,该部位可以进行枕骨髁螺钉置入,枕骨髁相对于枕骨大孔、头颅的位置变异性大。

Objective To measure the anatomical structure of the occipital condyle(OC)and the occipital foramen(FM)by three-dimensional reconstruction,and to analyze the morphological characteristics and relative positional relationship of the occipital condyle and occipital foramen,in order to provide anatomical parameters for the imaging diagnosis of the craniocervical junction and the choice of surgical approach.Methods Sixty normal subjects were selected with CT scans of the skull and upper cervical spine,including 30 males and 30 females,aged 20-65(48.18±16.17)years old.The data were imported into the Syngo.via VB10 B software,and the skull was reconstructed in three dimensions.To observe the shape of the occipital condyle and occipital foramen,and to measure the occipital condyle length,width,height,condyle inclination angle(CIA),longitudinal diameter,transverse diameter,area of the occipital foramen,the maximum distance between the cranial eyebrow and the posterior cranial point(SML),the crimson eyebrow on the SML line,the distance from the interpoint to the posterior margin of the occipital condyle(GOCP),the vertical distance between the anterior edge of the occipital foramen to the posterior margin of the occipital condyle(AOCP),and the distance from the medial margin of the left and right occipital condyles to the Y axis(OC-M),left and right occipital condyle posterior margin to X axis distance(OC-P);occipital condyle classification index(OCI),occipital condyle relative index of head(SOCI),midpoint on the SML straight line to the occipital condyle Marginal connection distance(COCP,COCP=GOCP-SML/2),and determine the type of relative positional relationship between left and right occipital condyles.Results The differences in anatomical length,width and height of the occipital condyle were statistically significant(P<0.05),and men were larger than women;the occipital foramen area,longitudinal diameter of the occipital foramen,SML,GOCP,AOCP had statistical differences(P<0.05).The lateral differences of occipital condyle inclination were statistically significant(P<0.05),and the left side was greater than the right side.The differences in OC-M and OC-P sides were statistically significant(P<0.05).The former was larger on the right than on the left;the latter was larger on the left than on the right.The longitudinal diameter of the occipital foramen was positively correlated with the area of the occipital foramen and AOCP;OCI classification result were as follows:typeⅠ(OCI<0.45)had 8 cases(13.33%),typeⅡ(0.45≤OCI<0.50)had 47 cases(78.33%),typeⅢ(OCI≥0.50)had 5 cases(8.33%).SOCI classification result were as follows:typeⅠ(SOCI<0.60)had 2 cases(3.33%),typeⅡ(0.60≤SOCI<0.75)had 54 cases(90.00%),typeⅢ(SOCI≥0.75)had 4 cases(6.67%).Conclusion The anatomical parameters of the occipital condyle in Inner Mongolia can be implanted with occipital condylar screws.The position of the occipital condyle relative to the foramen magnum and the skull is highly variable.