Imai Hiroshi, Kamada Tomomi, Takeba Jun, Shiraishi Yoshitaka, Mashima Naohiko, Miura Hiromasa
Department of Bone and Joint Surgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan,
J Orthop Sci. 2014 Sep;19(5):762-9. doi: 10.1007/s00776-014-0592-5. Epub 2014 Jun 23.
In periacetabular osteotomy for the treatment of developmental dysplasia of the hip, impairments in ADL due to limitations in hip flexion can occur when anterior displacement is added to lateral displacement in order to obtain sufficient femoral head coverage. This study was conducted to determine, by the range of motion (ROM) simulation based on CT images, the minimum angle of hip flexion and internal rotation at 90° of flexion that is necessary to avoid ADL impairments after eccentric rotational acetabular osteotomy (ERAO) and to estimate the angles of anterior femoral head coverage on plain radiography that enable the above flexion.
Of 47 hips treated with ERAO at our hospital from December 2007 to May 2012, 27 hips without progressive osteoarthritis which could be CT scanned were examined and included. The mean age at the time of surgery was 40.7 years (SD 1.8). The postoperative follow-up period was 30.2 months (SD 3.6). Two hips were in male patients and 25 hips were in female patients. The disease stage prior to surgery was pre-osteoarthritis in 5 hips, early in 11 hips, and progressive in 11 hips. We checked whether the patients were capable of activities that require deep hip flexion for the evaluation of postoperative ADL. Radiographic examination was performed before and one year after surgery to calculate LCE angle, Sharp angle, AHI, and VCA angle. The angle at which impingement of the displaced fragment of the bone and the femur appeared was measured using 3D CAD software, and the relationship between this angle and the physical findings, ADL impairment, or radiographic findings, were also examined.
22 out of 27 hips that were capable of 116° or more of flexion or 42° or more of internal rotation at 90° of flexion in ROM simulation showed the absence of ADL impairment and a postoperative VCA angle ≤42°, whereas 5 hips with 110° or less of flexion or 40° or less of internal rotation at 90° of flexion in ROM simulation had ADL impairments associated with limitations in hip flexion and a postoperative VCA angle ≥46°.
Anterior and lateral coverage requires a postoperative VCA angle of ≥20° to achieve anterior structural stability and an LCE angle of >25° to obtain adequate superior lateral coverage of the femoral head. A VCA angle ≤42° is required to avoid impingement during deep flexion. A VCA angle ≥46° is a probable risk factor for pincer FAI syndrome after ERAO.
在髋臼周围截骨术治疗发育性髋关节发育不良中，为获得足够的股骨头覆盖，在向外侧移位基础上增加前侧移位时，髋关节屈曲受限可能导致日常生活活动（ADL）受损。本研究旨在通过基于CT图像的运动范围（ROM）模拟，确定偏心旋转髋臼截骨术（ERAO）后避免ADL受损所需的最小髋关节屈曲角度以及屈曲90°时的内旋角度，并在X线平片上估计能实现上述屈曲的股骨头前侧覆盖角度。
2007年12月至2012年5月在我院接受ERAO治疗的47例髋关节中，纳入27例无进行性骨关节炎且可行CT扫描的髋关节。手术时的平均年龄为40.7岁（标准差1.8）。术后随访时间为30.2个月（标准差3.6）。男性患者2例，女性患者25例。术前疾病分期为骨关节炎前期5例，早期11例，进展期11例。我们检查患者是否能够进行需要深度髋关节屈曲的活动以评估术后ADL。在手术前和术后1年进行X线检查以计算外侧中心边缘角（LCE角）、夏普角、髋臼指数（AHI）和髋臼包容角（VCA角）。使用3D CAD软件测量移位骨块与股骨撞击出现时的角度，并检查该角度与体格检查结果、ADL受损情况或X线检查结果之间的关系。
在ROM模拟中，27例髋关节中有22例在屈曲90°时能够屈曲116°或更多或内旋42°或更多，这些患者显示无ADL受损且术后VCA角≤42°；而在ROM模拟中，5例在屈曲90°时屈曲110°或更少或内旋40°或更少的髋关节存在与髋关节屈曲受限相关的ADL受损，且术后VCA角≥46°。
前后侧覆盖需要术后VCA角≥20°以实现前侧结构稳定性，LCE角>25°以获得股骨头足够的上外侧覆盖。为避免深度屈曲时的撞击，需要VCA角≤42°。VCA角≥46°可能是ERAO后钳夹型股骨髋臼撞击综合征（FAI）的危险因素。
