Monazzam Shafagh, Williams Karly Ann, Shelton Trevor J, Calafi Arash, Haus Brian M
Department of Orthopedic Surgery, University of California Davis, Sacramento, CA, USA.
Hip Int. 2018 Sep;28(5):535-541. doi: 10.1177/1120700017752569. Epub 2018 May 17.
The anterior centre-edge angle (ACEA) describes anterior acetabular coverage on false profile radiographs. Variability associated with pelvic tilt, radiographic projection, and identifying the true anterior edge, causes discrepancies in measuring an accurate ACEA. Computed tomography (CT) has the potential of improving the accuracy of ACEA. However, because the ACEA on sagittal CT has been shown to not be equivalent to ACEA on false profile radiographs, the normal range of ACEA on CT currently remains unknown and cannot reliably be used to determine over/under coverage. We therefore asked: what is the normal variation of ACEA corrected for pelvic tilt on sagittal CT and how does this compare to dysplastic hips?
A retrospective review was conducted on patients 10-35 who underwent CT for non-orthopedic related issues and patients with known hip dysplasia. The ACEA was measured on a sagittal slice corresponding to the centre of the femoral head on the axial slice and adjusted for pelvic tilt. A statistical comparison was then performed.
A total of 320 normal patients and 22 patients with hip dysplasia were reviewed. The mean ACEA for all ages was 50° ± 8°, (range: 23-81º), with a larger mean ACEA for males (51°) than females (49°). The ACEA mean for dysplastic hips was 30° ± 11° with a statistically significant difference in mean from the normal hip group ( p < 0.0001).
The ACEA can be reliably measured on sagittal CT and significantly differs from dysplastic hips. ACEA measurements above 66° or below 34° may represent anterior over and under coverage.
前中心边缘角（ACEA）用于描述假斜位X线片上髋臼的前侧覆盖情况。由于骨盆倾斜、X线投照以及确定真正的前边缘所导致的变异性，使得准确测量ACEA存在差异。计算机断层扫描（CT）有可能提高ACEA测量的准确性。然而，由于矢状面CT上的ACEA已被证明与假斜位X线片上的ACEA不相等，目前CT上ACEA的正常范围仍不清楚，也不能可靠地用于确定覆盖过度或不足。因此，我们提出疑问：经骨盆倾斜校正后的矢状面CT上ACEA的正常变异是多少，与发育不良的髋关节相比情况如何？
对因非骨科相关问题接受CT检查的10至35岁患者以及已知髋关节发育不良的患者进行回顾性研究。在与轴位片上股骨头中心相对应的矢状面上测量ACEA，并对骨盆倾斜进行校正。然后进行统计学比较。
共纳入320例正常患者和22例髋关节发育不良患者。所有年龄组的平均ACEA为50°±8°（范围：23 - 81°），男性的平均ACEA（51°）高于女性（49°）。发育不良髋关节的ACEA平均值为30°±11°，与正常髋关节组相比，平均值有统计学显著差异（p < 0.0001）。
可以在矢状面CT上可靠地测量ACEA，且与发育不良的髋关节有显著差异。ACEA测量值高于66°或低于34°可能表示前侧覆盖过度或不足。
