Bragdon Charles R, Martell John M, Estok Daniel M, Greene Meridith E, Malchau Henrik, Harris William H
Orthopaedic Biomechanics and Biomaterials Laboratory and the Adult Reconstructive Unit of the Department of Orthopaedic Surgery of Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
J Orthop Res. 2005 Jul;23(4):720-5. doi: 10.1016/j.orthres.2004.07.008. Epub 2005 Mar 2.
Due to the uneven and often inadequate quality of cross-table lateral hip radiographs, many radiographic studies of femoral head penetration into polyethylene in total hip arthroplasty are limited to the two-dimensional measurement of femoral head penetration using the A/P film only. We postulated that the use of two oblique frontal projections at 90 degrees to each other would improve the three-dimensional evaluation. Using an established hip phantom, the idealized accuracy and precision of the three-dimensional Martell method was evaluated, contrasting the standard A/P and cross-table lateral projections versus a pair of oblique projections by four independent readers. Accuracy and precision resulting from the use of two oblique projections (average accuracy +/-63 microm, precision +/-26 microm) were similar to that obtained using the conventional A/P and cross-table lateral views (accuracy +/-54 microm, precision +/-22 microm), though the results of the two oblique views were slightly more variable. These observations suggest that by using two oblique A/P projections, the major disadvantage of using the cross-table lateral films, namely the variable quality of the images, is avoided. Perhaps, therefore, the utility and availability of three-dimensional data in comparable clinical studies may be improved.
由于髋关节前后位（cross-table lateral）X线片质量参差不齐且常常欠佳，许多关于全髋关节置换术中股骨头向聚乙烯内穿透情况的影像学研究仅限于仅使用前后位（A/P）片对股骨头穿透进行二维测量。我们推测，使用相互呈90度的两个斜位正位投照会改善三维评估。使用一个已确立的髋关节模型，评估了三维马特尔（Martell）方法的理想化准确性和精确性，由四位独立阅片者对比标准的前后位和髋关节前后位X线片与一对斜位投照。使用两个斜位投照得出的准确性和精确性（平均准确性±63微米，精确性±26微米）与使用传统前后位和髋关节前后位视图所获得的结果（准确性±54微米，精确性±22微米）相似，尽管两个斜位视图的结果变化略大。这些观察结果表明，通过使用两个斜位前后位投照，可以避免使用髋关节前后位X线片的主要缺点，即图像质量参差不齐的问题。因此，在可比的临床研究中三维数据的实用性和可获取性或许会得到改善。
