CT三维后处理技术在髋关节特定参考系中相关参数的测量应用*

目的: 探讨髋关节相关参数在特定平面与常规平面中测量数据差异,为髋关节三维数据的测量提供标准化依据。方法: 选取32例成人(成人组)及16例大体解剖标本(标本组)正常髋关节的CT图像进行三维重建,在特定平面参照系内重建三维图像,对髋关节的sharp角、外展角、前倾角、中心边缘角、髋臼前后径、髋臼深径进行测量,同时与临床上普遍应用的以人体仰卧时水平面为常规平面参照系,对上述指标进行对比分析。采用t检验、非参数Mann-Whitney U检验和Wilcoxon带符号等级检验进行相关数据的统计学分析。结果: 两个参照系下所测数据相比较,标本组中右侧前倾角指标存在差异(P＜0.05);成人组中两侧髋臼前后径、两侧前倾角、右侧外展角相比,差异无统计学意义(P＞0.05)。总样本中,两侧髋臼前后径、两侧前倾角、左侧外展角相比,差异不显著,其余均差异显著(P＜0.05)。特定平面参照系下,成人组左、右侧髋臼深径均大于标本组(P＜0.05);在成人组、标本组和二组合并样本中,髋臼左右两侧样本各项指标和整体左右两侧样本各项指标间均无显著差异(P＞0.05)。结论: 成人在体标本与大体解剖学湿标本的左右髋臼与髋臼角度参数值测量不受体位影响,该参照系可以在一定程度上减少因强制体位所导致的测量误差,能够较采用常规平面参照系所测数据更为客观准确地反映髋臼的实际情况。

The application of CT three-dimensional post-processing technology in the measurement of relevant parameters in a specific reference frame of the hip joint

Objective: To explore the difference of measurement data of hip joint related parameters in specific plane and conventional plane, and to provide standardized basis for the measurement of three-dimensional data of hip joint. Methods: The CT images of 32 adults ( adult group ) and 16 general anatomical specimens ( specimen group ) of normal hip joint were selected for three-dimensional reconstruction, and the three-dimensional images were reconstructed in a specific plane reference frame. The sharp angle, abduction angle, anteversion angle, central edge angle, acetabular anteroposterior diameter and acetabular depth of the hip joint were measured. At the same time, the above indexes were compared and analyzed with the conventional plane reference frame, which was widely used in clinical practice. Statistical analysis was performed using t test, nonparametric Mann-Whitney U test and Wilcoxon signed rank test. Results: Compared with the measured data under the two reference frames, there was a difference in the right rake angle index in the specimen group (P＜0.05). There was no significant difference in the anterior and posterior diameters of both sides of the acetabulum, the anterior inclination angles of both sides, and the right abduction angle in the adult group (P＞0.05). In the total sample, there was no significant difference in the anterior and posterior diameters of both sides of the acetabulum, the anterior inclination angles of both sides, and the left abduction angle, but there were significant differences in other indicators (P＜0.05). Under the specific plane reference frame, the left and right acetabular depths in the adult group were larger than those in the specimen group (P＜0.05). There was no significant difference in the indicators of the left and right sides of the acetabulum among the adult group, the specimen group and the two combinations (P＞0.05). Conclusion: The measurement of the angle parameters of the left and right acetabulum and the acetabulum in adult cadavers and gross anatomical wet specimens is not affected by the receptor position. The reference frame can reduce the measurement error caused by the forced position to a certain extent, and can reflect the actual situation of the acetabulum more objectively and accurately than the data measured by the conventional plane reference frame.