Knafo Y, Houfani F, Zaharia B, Egrise F, Clerc-Urmès I, Mainard D
Service de Chirurgie Orthopédique, Traumatologique et Arthroscopique, Hôpital Central, CHRU Nancy, Av de Lattre de Tassigny, 54000 Nancy, France.
Pôle des Structures de Soutien à la Recherche, CHRU Nancy, Av de Lattre de Tassigny, 54000 Nancy, France.
Biomed Res Int. 2019 Mar 10;2019:1932191. doi: 10.1155/2019/1932191. eCollection 2019.
Two-dimensional (2D) planning on standard radiographs for total hip arthroplasty may not be sufficiently accurate to predict implant sizing or restore leg length and femoral offset, whereas 3D planning avoids magnification and projection errors. Furthermore, weightbearing measures are not available with computed tomography (CT) and leg length and offset are rarely checked postoperatively using any imaging modality. Navigation can usually achieve a surgical plan precisely, but the choice of that plan remains key, which is best guided by preoperative planning. The study objectives were therefore to (1) evaluate the accuracy of stem/cup size prediction using dedicated 3D planning software based on biplanar radiographic imaging under weightbearing and (2) compare the preplanned leg length and femoral offset with the postoperative result. This single-centre, single-surgeon prospective study consisted of a cohort of 33 patients operated on over 24 months. The routine clinical workflow consisted of preoperative biplanar weightbearing imaging, 3D surgical planning, navigated surgery to execute the plan, and postoperative biplanar imaging to verify the radiological outcomes in 3D weightbearing. 3D planning was performed with the dedicated hipEOS® planning software to determine stem and cup size and position, plus 3D anatomical and functional parameters, in particular variations in leg length and femoral offset. Component size planning accuracy was 94% (31/33) within one size for the femoral stem and 100% (33/33) within one size for the acetabular cup. There were no significant differences between planned versus implanted femoral stem size or planned versus measured changes in leg length or offset. Cup size did differ significantly, tending towards implanting one size larger when there was a difference. Biplanar radiographs plus hipEOS planning software showed good reliability for predicting implant size, leg length, and femoral offset and postoperatively provided a check on the navigated surgery. Compared to previous studies, the predictive results were better than 2D planning on conventional radiography and equal to 3D planning on CT images, with lower radiation dose, and in the weightbearing position.
全髋关节置换术在标准X线片上进行的二维（2D）规划可能不够准确，无法预测植入物尺寸或恢复腿长和股骨偏移，而三维（3D）规划可避免放大和投影误差。此外，计算机断层扫描（CT）无法进行负重测量，术后很少使用任何成像方式检查腿长和偏移。导航通常可以精确实现手术计划，但该计划的选择仍然是关键，最好由术前规划指导。因此，本研究的目的是：（1）评估基于双平面X线成像在负重情况下使用专用3D规划软件预测柄/臼杯尺寸的准确性；（2）比较术前规划的腿长和股骨偏移与术后结果。这项单中心、单术者的前瞻性研究纳入了一组在24个月内接受手术的33例患者。常规临床流程包括术前双平面负重成像、3D手术规划、导航手术以执行计划，以及术后双平面成像以在3D负重下验证放射学结果。使用专用的HipEOS®规划软件进行3D规划，以确定柄和臼杯的尺寸和位置，以及3D解剖和功能参数，特别是腿长和股骨偏移的变化。股骨柄的组件尺寸规划准确率在一个尺寸范围内为94%（31/33），髋臼杯在一个尺寸范围内为100%（33/33）。计划的股骨柄尺寸与植入的股骨柄尺寸之间，以及计划的腿长或偏移变化与测量值之间均无显著差异。臼杯尺寸确实存在显著差异，有差异时倾向于植入大一个尺寸的臼杯。双平面X线片加上HipEOS规划软件在预测植入物尺寸、腿长和股骨偏移方面显示出良好的可靠性，并且术后可对导航手术进行检查。与先前的研究相比，预测结果优于传统X线片上的2D规划，与CT图像上的3D规划相当，且辐射剂量更低，并且是在负重位置。
