Orthopaedic Surgery, Sensory and Motor System Medicine, Surgical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Division of Science for Joint Reconstruction, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-8655, Japan.
J Orthop Surg Res. 2021 Mar 15;16(1):192. doi: 10.1186/s13018-021-02346-0.
Rotational acetabular osteotomy (RAO) is a type of pelvic osteotomy performed to improve the acetabular bony coverage against the femoral head for patients with acetabular dysplasia. The acetabular bony coverage is ideally evaluated three-dimensionally; however, there is a paucity of published data regarding three-dimensional morphology in patients with long-term excellent outcome after RAO. The present study investigated the characteristics of three-dimensional acetabular morphology with long-term excellent outcome after RAO in comparison to patients with normal hip joints and those converted to total hip arthroplasty (THA) after RAO because of osteoarthritis (OA) progression.
Anteroposterior plain radiograph and computed tomography data of 57 hip joints (17 joints with excellent outcome 20 years or more after RAO, 16 normal joints, and 20 joints converted to THA after RAO) were analyzed. The two-dimensional lateral center-edge (CE) angle from plain radiographs and acetabular anteversion, anterior acetabular sector angle, and posterior sector angle from computed tomography (CT) images were calculated.
Compared with patients converted to THA, all parameters in patients with long-term excellent outcome after RAO were similar to those in patients with normal hip joints, particularly in the three-dimensional analyses. The anterior bony coverage was excessive, whereas the posterior bony coverage was deficient in patients converted to THA after RAO. Anterior bony impingement and posterior instability may be the cause of OA progression after RAO.
Caution must be taken to avoid rotating the separated fragment excessively to the anterior direction during RAO to prevent OA progression and achieve long-term excellent outcome.
旋转髋臼截骨术（RAO）是一种骨盆截骨术，用于改善髋臼骨对股骨头的覆盖，适用于髋臼发育不良的患者。髋臼骨覆盖情况理想的评估方式是三维评估；然而，RAO 术后长期疗效优异的患者的髋臼三维形态的相关数据却很少。本研究通过比较 RAO 术后长期疗效优异的患者、髋关节正常的患者和因关节炎（OA）进展而转为全髋关节置换术（THA）的患者，探讨了 RAO 术后长期疗效优异患者的三维髋臼形态特征。
对 57 个髋关节（17 个 RAO 术后 20 年或以上疗效优异的关节、16 个正常关节和 20 个因 RAO 转为 THA 的关节）的前后位平片和 CT 数据进行分析。从平片计算二维外侧中心边缘（CE）角，从 CT 图像计算髋臼前倾角、前髋臼扇形角和后髋臼扇形角。
与转为 THA 的患者相比，RAO 术后长期疗效优异的患者的所有参数均与髋关节正常的患者相似，特别是在三维分析中。转为 THA 的患者髋臼前骨覆盖过度，而后骨覆盖不足。髋臼前骨撞击和后骨不稳定可能是 RAO 后 OA 进展的原因。
在 RAO 过程中必须注意避免将分离的骨块过度向前旋转，以防止 OA 进展并获得长期的优异疗效。
