Yang Yuhui, Ma Yuanchen, Li Qingtian, Lin Bofu, Dong Hang, Zheng Qiujian
Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, China.
Quant Imaging Med Surg. 2022 May;12(5):2904-2916. doi: 10.21037/qims-21-803.
Acetabular reconstruction in Crowe type IV developmental dysplasia of the hip (DDH) can be a challenging procedure for surgeons. A high risk of acetabular revision has been reported to be associated with extremely small acetabular prostheses. However, to our knowledge, quantitative morphological and coverage evaluations of the true acetabulum in Crowe IV hips have been infrequently conducted. Useful bony landmarks for acetabular reconstruction can also facilitate satisfactory intraoperative implantation. The aim of the present study was to investigate the anatomical size, orientation angles, and 2/3-dimensional (2D/3D) coverage parameters of the true acetabulum in Crowe IV hips; evaluate the feasibility of standard cup (>44 mm) implantation at the true acetabulum in Crowe IV hips; and identify the optimal position and useful bony landmarks of the acetabular reaming center in Crowe IV hips.
A total of 42 Crowe IV hips in 37 patients and 36 normal hips were included in this study. Based on pelvic 3D computed tomography (CT) reconstruction, anatomical size and integral volume of the true acetabulum were measured quantitatively. Through standard-size cup-simulated implantation, morphological assessments of the true acetabulum included Cup-CE, Cup-Sharp, acetabular anteversion angle, and thickness of the medial wall. Acetabular sector angles (ASAs) and the component coverage ratio were measured to provide coverage indices. Acetabular reconstruction was also performed at different vertical levels to measure medial bone stock and 3D component coverage. Bony landmarks for optimal component center location were also determined.
The anatomic shape and volume of the acetabular triangle were significantly smaller in Crowe IV hips. Compared with the control group, the dysplastic acetabulum was more anteverted and abductive, with a thicker medial wall. According to the true acetabulum, bone stock was relatively sufficient in the posterior direction and prominently deficient in the anterosuperior and superior direction. The average 3D component coverage reached 79.89% by standard-sized cup implantation, with the most satisfactory coverage achieved at the true acetabulum (at the level of 13.32 mm above the transverse acetabular ligament). Regarding the component opening plane, the optimal component center was located at the midpoint between the superolateral and posteroinferior points of the true acetabulum.
The most satisfactory coverage was achieved at the level of the true acetabulum, of which the most prominent deficiency was mainly located in the anterosuperior and superior directions. The optimal component center was determined to be the midpoint between the superolateral and posteroinferior points of the true acetabulum.
对于外科医生而言，在Crowe IV型发育性髋关节发育不良（DDH）中进行髋臼重建是一项具有挑战性的手术。据报道，髋臼假体极小会导致髋臼翻修的高风险。然而，据我们所知，对Crowe IV型髋关节的真性髋臼进行定量形态学和覆盖范围评估的情况并不常见。用于髋臼重建的有用骨性标志也有助于术中实现满意的植入。本研究的目的是调查Crowe IV型髋关节真性髋臼的解剖尺寸、方位角和二维/三维（2D/3D）覆盖参数；评估在Crowe IV型髋关节真性髋臼植入标准髋臼杯（>44 mm）的可行性；并确定Crowe IV型髋关节髋臼扩孔中心的最佳位置和有用骨性标志。
本研究共纳入37例患者的42个Crowe IV型髋关节和36个正常髋关节。基于骨盆三维计算机断层扫描（CT）重建，定量测量真性髋臼的解剖尺寸和整体体积。通过标准尺寸髋臼杯模拟植入，对真性髋臼进行形态学评估，包括髋臼杯-CE角、髋臼杯-Sharp角、髋臼前倾角和内侧壁厚度。测量髋臼扇形角（ASAs）和假体覆盖率以提供覆盖指标。还在不同垂直层面进行髋臼重建，以测量内侧骨量和三维假体覆盖情况。同时确定最佳假体中心位置的骨性标志。
Crowe IV型髋关节髋臼三角的解剖形状和体积明显较小。与对照组相比，发育不良的髋臼更前倾和外展，内侧壁更厚。根据真性髋臼，后方骨量相对充足，而在前上和上方方向明显不足。通过标准尺寸髋臼杯植入，平均三维假体覆盖率达到79.89%，在真性髋臼（髋臼横韧带上方13.32 mm水平）实现了最满意的覆盖。关于假体开口平面，最佳假体中心位于真性髋臼上外侧和后下点之间的中点。
在真性髋臼水平实现了最满意的覆盖，其中最明显的不足主要位于前上和上方方向。确定最佳假体中心为真性髋臼上外侧和后下点之间的中点。
