Anatomical position
Japanese patients aged three to five years were included in the study. abdominal tumor, leukemia, and appendicitis), between 20 and were stored in a database. The investigation was based on CT images of the pelvis that were obtained for several reasons, including abdominal diseases (e.g. All experiments were performed in accordance with relevant guidelines and the regulations of our university. 1106) the requirement for informed patient consent was waived due to the retrospective nature of the study. This retrospective study was approved by the ethical committee of our university (no. Therefore, the present study aimed to use computed tomography (CT) data to evaluate the exact anatomical position of Graf’s standard plane in the pelvis and to ascertain the correlation between this position and pelvic morphology in children without abnormal pelvic morphology. If the exact location of the standard plane in the pelvis is identified, it may contribute to improving the accuracy of the Graf method.
It is also reported that the Graf method has low inter- and intra-observer agreement because it is highly dependent on the ability of the examiner.
Moreover, although it is stated that the standard plane cannot be obtained if the probe is rotated anteriorly or posteriorly, there is no report on how much the standard plane is tilted with respect to the pelvis. Graf further stated that the lower limb of the bony ilium refers to the center of the acetabulum, that the mid-portion of the acetabular roof should be straight and parallel to the probe, and that the standard plane cannot be obtained if the probe is rotated anteriorly or posteriorly.ĭespite the importance of the standard plane setting in the performance of the Graf method, to the best of our knowledge, no previous report has discussed the detailed anatomical location of the standard plane and the relationship of this position with pelvic morphology. Accordingly, Graf explained that the principles of the ‘standard plane’ were strongly based on: (1) the lower limb of the bony ilium in the depth of the acetabular fossa, (2) the mid-portion of the acetabular roof, and (3) the acetabular labrum. This method is based on the measurement of a bone angle (alpha) and a soft-tissue angle (beta) from a coronal two-dimensional (2D) US image on the standard plane. Presently, the Graf method is the most widely used standard for DDH evaluation worldwide. In newborn infants, ultrasound (US) imaging of the hip joint is widely used for the early detection of developmental dysplasia of the hip (DDH). This information may be useful in improving the ease of ultrasonographic examination of DDH. We found that Graf's standard plane, as determined by the CT scan, tilts slightly posteriorly. The average AA′ was -8.27° and AA′ had a significant correlation with acetabular anteversion (Spearman’s ρ=0.40**, p<0.01). Moreover, we measured the pelvic rotation, acetabular anteversion, and acetabular coverage and evaluated the correlation between AA′ and these morphological parameters.
The anterior rotational angle (clockwise, viewing from the right side) was measured as the positive AA′. AA′ was defined as the angle from plane A to plane A′ on the sagittal plane. We determined that Graf’s standard plane could be approximated by rotating plane A until the outer wall of the ilium was parallel to the sagittal plane, and we defined this as plane A′.
We defined the coronal plane that passed through the center of the bilateral femoral head as plane A. We retrospectively assessed the pelvic CT data of 32 children (64 hips) aged three to five years without abnormal pelvic morphology and measured the pelvic winging and acetabular anteversion and coverage. The aim of this study was to evaluate the exact anatomical position of Graf’s standard plane in the pelvis and to ascertain the correlation between this position and pelvic morphology in children without abnormal pelvic morphology. However, no previous reports have discussed the detailed anatomical location of the plane. The Graf method is the most widely used ultrasonographic method for evaluating developmental dysplasia of the hip (DDH), and it relies on a set standard plane.