Kobayashi Daigo, Choe Hyonmin, Kobayashi Naomi, Tezuka Taro, Ike Hiroyuki, Inaba Yutaka
Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Japan.
Department of Orthopedic Surgery, Yokohama City University Medical Center, Yokohama, Japan.
Arthroplast Today. 2020 Jul 23;6(3):532-537. doi: 10.1016/j.artd.2020.06.004. eCollection 2020 Sep.
Although rotational changes in lower limb alignment after total hip arthroplasty (THA) affect functional stem anteversion, less is known about the effects of femoral rotational alignment in the standing position. This study investigated postoperative changes in femoral rotation and evaluated the association with whole-body alignment in patients who underwent THA.
Sixty-five patients with unilateral hip osteoarthritis who underwent THA were enrolled. Preoperative and postoperative femoral rotation in the standing and supine positions were measured using EOS 2D/3D X-ray imaging system and computed tomography. Negative and positive changes in femoral rotation angle were indicative of internal and external rotation, respectively. The associations between femoral rotation and preoperative clinical and radiological factors were investigated.
Femoral rotation showed significant internal changes in both the standing (-4.7° ± 11.0°) and supine (-3.5°± 10.9°) positions after THA. The preoperative femoral rotation angle, knee flexion angle, sagittal vertical axis (SVA), lumbar lordosis, body mass index, age, and internal and external rotation angles of the hip range of motion on the contralateral side were significantly correlated with femoral rotation in the standing position after THA. Multiple regression analysis showed that preoperative femoral rotation (β = 0.416, < .001) and SVA (β = 0.216, = .040) were significant predictors of postoperative femoral rotation in the standing position.
Femoral rotation had significant association with the patient-inherent posture represented by the SVA in the standing position. Because extensive external change of femoral rotation may increase the risk of hip impingement and dislocation, careful attention is required in patients with external femoral rotation and forward bent posture in the preoperative standing position.
尽管全髋关节置换术（THA）后下肢对线的旋转变化会影响假体柄前倾角，但关于站立位时股骨旋转对线的影响知之甚少。本研究调查了接受THA患者术后股骨旋转的变化，并评估了其与全身对线的相关性。
纳入65例接受THA的单侧髋骨关节炎患者。使用EOS 2D/3D X线成像系统和计算机断层扫描测量站立位和仰卧位术前及术后的股骨旋转。股骨旋转角度的负向和正向变化分别表示内旋和外旋。研究了股骨旋转与术前临床和放射学因素之间的相关性。
THA术后，站立位（-4.7°±11.0°）和仰卧位（-3.5°±10.9°）的股骨旋转均显示出显著的内旋变化。术前股骨旋转角度、膝关节屈曲角度、矢状垂直轴（SVA）、腰椎前凸、体重指数、年龄以及对侧髋关节活动范围的内旋和外旋角度与THA术后站立位的股骨旋转显著相关。多元回归分析显示，术前股骨旋转（β = 0.416，P <.001）和SVA（β = 0.216，P =.040）是术后站立位股骨旋转的重要预测因素。
股骨旋转与站立位时由SVA代表的患者固有姿势显著相关。由于股骨旋转的广泛外旋变化可能增加髋关节撞击和脱位的风险，因此对于术前站立位存在股骨外旋和前倾姿势的患者需要格外关注。
