Takada Ryohei, Jinno Tetsuya, Miyatake Kazumasa, Watanabe Naoto, Koga Hideyuki, Yoshii Toshitaka, Okawa Atsushi
Department of Orthopaedic Surgery, Medical Hospital, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
Eur J Orthop Surg Traumatol. 2022 Apr;32(3):497-503. doi: 10.1007/s00590-021-03001-4. Epub 2021 May 22.
Whether different body positions during surgery affect postoperative stem alignment in total hip arthroplasty (THA) remains unclear. The purpose of this study was to clarify differences in tapered wedge stem alignment between supine and lateral positions in THA under the modified Watson-Jones anterolateral approach.
We reviewed 242 consecutive, primary cementless THAs performed with ceramic-on-cross-linked polyethylene via the modified Watson-Jones approach in either supine or lateral positions between 2009 and 2015 (supine group: 113 cases; lateral group: 129 cases). No specific reasons to select supine or lateral positions for the surgery were given during the study period. Computed tomography was performed pre- and postoperatively to measure preoperative femoral anteversion and postoperative stem anteversion, respectively. Stem alignment in coronal and sagittal planes was also evaluated.
Mean difference in stem anteversion and femoral anteversion was 8.6 ± 9.4 in the supine position and 13.0 ± 11.4 in the lateral position (p = 0.0013). Although no significant difference was seen between groups for stem alignment in the coronal plane, flexed implantation was more likely in the supine group (46/113, 40.7%) than in the lateral group (20/129, 15.5%). A significant correlation was found between femoral anteversion and stem anteversion in both the supine and lateral groups (r = 0.68, p < 0.0001 and r = 0.52, p < 0.0001, respectively).
Although stem anteversion was more strongly correlated with femoral anteversion in the supine position than in the lateral position, neutral position in the sagittal plane was more likely to be found with the lateral position than with the supine position. Surgeons can achieve ideal stem positioning by considering these results in the modified Watson-Jones approach in both the supine and lateral positions.
在全髋关节置换术（THA）中，手术期间不同的身体姿势是否会影响术后假体柄的对线尚不清楚。本研究的目的是阐明在改良的沃森-琼斯前外侧入路的THA中，仰卧位和侧卧位之间锥形楔形假体柄对线的差异。
我们回顾了2009年至2015年间通过改良的沃森-琼斯入路，采用陶瓷对交联聚乙烯进行的242例连续初次非骨水泥型THA手术（仰卧位组：113例；侧卧位组：129例）。在研究期间，未给出选择仰卧位或侧卧位进行手术的具体原因。分别在术前和术后进行计算机断层扫描，以测量术前股骨前倾角和术后假体柄前倾角。还评估了冠状面和矢状面的假体柄对线情况。
仰卧位假体柄前倾角与股骨前倾角的平均差值为8.6±9.4，侧卧位为13.0±11.4（p = 0.0013）。虽然两组在冠状面的假体柄对线方面没有显著差异，但仰卧位组（46/113，40.7%）比侧卧位组（20/129，15.5%）更倾向于屈曲植入。仰卧位组和侧卧位组的股骨前倾角与假体柄前倾角之间均存在显著相关性（分别为r = 0.68，p < 0.0001和r = 0.52，p < 0.0001）。
虽然仰卧位时假体柄前倾角与股骨前倾角的相关性比侧卧位更强，但矢状面的中立位在侧卧位比仰卧位更易实现。在改良的沃森-琼斯入路中，无论是仰卧位还是侧卧位，外科医生通过考虑这些结果都可以实现理想的假体柄定位。
