Division of Comprehensive Geriatrics in Community, Niigata University Graduate School of Medical and Dental Sciences, 1-757, Asahimachi-do-ri, Chuou ku, Niigata City, Niigata Prefecture, 951-8167, Japan.
Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
J Orthop Surg Res. 2019 May 9;14(1):126. doi: 10.1186/s13018-019-1165-2.
Sagittal spinal balance and standing posture are affected by pelvic morphology, especially pelvic incidence (PI). However, it is not difficult to identify the hip center because of overlap of the pelvis, image contrast, and soft tissue artifacts. Measurements of PI are not always suitable in all patients, especially those with osteoarthritis of the hip joint whose femoral head is nonspherical, subluxed, or dislocated. We measured PI, pelvic tilt (PT), and sacral slope (SS) as anatomical parameters using a novel three-dimensional measurement in order to compare the pelvic morphology between normal, healthy men and women.
In this cross-sectional study, we evaluated 108 Japanese subjects (55 men, 53 women) without low back or knee pain. We used the three-dimensional pelvis model adjusted to the anterior pelvic plane and measured the pelvic parameters. The subjects were stratified by age (< 50 versus ≥ 50 years) and sex. Intraobserver and interobserver reliabilities were calculated with intraclass correlation coefficients.
There was no significant difference in PI, anatomical-PT, and anatomical-SS between sexes. There was a strong correlation between PI and anatomical-SS in men and women (R = 0.790 and 0.715, respectively). Values of anatomical-PT were lower, and values of anatomical-SS were greater among older subjects than among younger subjects; the value of PI was similar between younger and older subjects. Intraobserver and interobserver mean absolute differences were about 2 mm and 2°, respectively; the intraclass correlation coefficient was > 0.87.
We found a strong correlation between PI and anatomical-SS in men and women. This novel measurement concept may be useful to estimate PI from anatomical-SS because the measurements of PI are not always suitable in all patients, especially those with osteoarthritis of the hip joint whose femoral head is not spherical or whose femoral head is subluxed or dislocated. This is the first report to describe the relationship between PI, anatomical-PT, and anatomical-SS as morphologic parameters with a high interclass correlation coefficient for intraobserver and interobserver reliabilities.
矢状位脊柱平衡和站立姿势受骨盆形态影响，尤其是骨盆入射角（PI）。然而，由于骨盆重叠、图像对比度和软组织伪影，髋关节中心并不容易识别。PI 的测量并不总是适用于所有患者，特别是髋关节骨关节炎患者，其股骨头呈非球形、半脱位或脱位。我们使用一种新的三维测量方法测量 PI、骨盆倾斜（PT）和骶骨倾斜（SS）等解剖学参数，以比较正常健康男性和女性的骨盆形态。
在这项横断面研究中，我们评估了 108 名无下腰痛或膝关节痛的日本受试者（55 名男性，53 名女性）。我们使用调整至前骨盆平面的三维骨盆模型测量骨盆参数。根据年龄（<50 岁与≥50 岁）和性别对受试者进行分层。采用组内相关系数（intraclass correlation coefficient，ICC）评估观察者内和观察者间可靠性。
男女之间 PI、解剖学 PT 和解剖学 SS 无显著差异。PI 与男女解剖学 SS 之间存在很强的相关性（R 值分别为 0.790 和 0.715）。与年轻受试者相比，老年受试者的解剖学 PT 值较低，解剖学 SS 值较大；而年轻和老年受试者的 PI 值相似。观察者内和观察者间平均绝对差值分别约为 2mm 和 2°，ICC 均>0.87。
我们发现男女之间 PI 与解剖学 SS 之间存在很强的相关性。这种新的测量概念可能有助于从解剖学 SS 估计 PI，因为 PI 的测量并不总是适用于所有患者，特别是髋关节骨关节炎患者，其股骨头呈非球形或股骨头半脱位或脱位。这是第一篇描述 PI、解剖学 PT 和解剖学 SS 作为形态学参数的关系的报告，其观察者内和观察者间可靠性的 ICC 值较高。
