Wada Hiroshi, Mishima Hajime, Yoshizawa Tomohiro, Sugaya Hisashi, Nishino Tomofumi, Yamazaki Masashi
Department of Orthopaedic Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
Department of Orthopaedic Surgery, Institute of Clinical Medicine, and University Hospital, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
Open Orthop J. 2016 Mar 22;10:26-35. doi: 10.2174/1874325001610010026. eCollection 2016.
In cementless total hip arthroplasty, imageless computer-assisted navigation is usually used to register the anterior pelvic plane (APP). The accuracy of this method is influenced by the subcutaneous tissues overlying the registration landmarks. On the other hand, the acetabular center axis (ACA) is determined from the acetabular rim. Precise registration of the ACA is possible because of direct palpation using a pointer. Imageless navigation using the ACA usually targets patients with normal acetabular morphology. The aim of this study was to investigate the accuracy of imageless navigation using the ACA instead of the APP in patients with normal or deformed acetabular rims.
The intraoperative cup position was compared with that obtained from the postoperative computed tomography (CT) images in 18 cases.
The inclination angle derived from the navigation system was 3.4 ± 5.3 degrees smaller and the anteversion angle was 1.4 ± 3.1 degrees larger than those derived from the CT images.
The inclination cup angle of the navigation system was significantly inferior to the true value, particularly in cases with large anterior osteophytes.
在非骨水泥型全髋关节置换术中，通常使用无图像计算机辅助导航来确定骨盆前平面（APP）。该方法的准确性受覆盖注册标志的皮下组织影响。另一方面，髋臼中心轴（ACA）由髋臼边缘确定。由于使用指针进行直接触诊，因此可以精确注册ACA。使用ACA的无图像导航通常针对髋臼形态正常的患者。本研究的目的是调查在髋臼边缘正常或畸形的患者中，使用ACA而非APP进行无图像导航的准确性。
比较了18例患者术中髋臼杯位置与术后计算机断层扫描（CT）图像获得的位置。
导航系统得出的倾斜角度比CT图像得出的角度小3.4±5.3度，前倾角大1.4±3.1度。
导航系统的髋臼杯倾斜角度明显低于真实值，尤其是在前侧骨赘较大的情况下。
