Claus Alexandra M, Engh C Anderson, Sychterz Christi J, Xenos John S, Orishimo Karl F, Engh Charles A
Anderson Orthopaedic Research Institute, Alexandra, Virginia 22307, USA.
J Bone Joint Surg Am. 2003 Aug;85(8):1519-26. doi: 10.2106/00004623-200308000-00013.
Radiographs are the standard clinical tool used to monitor patients with pelvic osteolysis after total hip arthroplasty; however, previous reports have questioned the value and accuracy of this method. With use of a cadaveric model, we investigated the accuracy of radiographs in determining the location and size of periacetabular osteolysis.
We implanted total hip arthroplasty components in eight cadaveric hips and made four radiographs of each hip from different views. We then removed the components and created two pelvic defects in each hip. We measured the volume of each defect, reimplanted the components, and made another set of radiographs. The defects were then enlarged two more times, with the volume measured and another set of radiographs made each time. In total, 128 radiographs were made of forty-eight lesions. An orthopaedist who was blinded to the location of the lesions assessed the radiographs with regard to the presence and size of osteolytic lesions.
The overall sensitivity for the detection of osteolysis on a single radiograph was 41.5%, and the overall specificity was 93.0%. Sensitivity was dependent on the location and size of the lesions but not on the radiographic view. Sensitivity ranged from 72% for lesions in the ilium to </=15% for lesions in the ischium and acetabular rim. The detection rate for lesions with a volume of >10 cm (3) was significantly higher than that for smaller lesions (p < 0.001). When all four radiographic views of one lesion were analyzed together, sensitivity increased to 73.6%. Despite the low sensitivity, specificity remained high, indicating that once osteolysis is evident radiographically, the likelihood that a lesion truly exists is high. Additionally, we found that the extent of osteolysis was substantially underestimated on radiographs.
The use of radiographs to assess and monitor osteolysis has both limitations and merits. Using multiple views, an experienced orthopaedist identified only 73.6% of pelvic lesions. However, once a pelvic osteolytic lesion is evident radiographically, the likelihood that it truly exists is high.
X线片是用于监测全髋关节置换术后骨盆骨质溶解患者的标准临床工具；然而，既往报告对该方法的价值和准确性提出了质疑。我们使用尸体模型，研究了X线片在确定髋臼周围骨质溶解的位置和大小方面的准确性。
我们在八个尸体髋关节中植入全髋关节置换组件，并从不同角度对每个髋关节拍摄四张X线片。然后取出组件，在每个髋关节中制造两个骨盆缺损。我们测量每个缺损的体积，重新植入组件，并再拍摄一组X线片。然后将缺损再扩大两次，每次测量体积并拍摄另一组X线片。总共对48个病灶拍摄了128张X线片。一位对病灶位置不知情的骨科医生对X线片上骨质溶解病灶的存在和大小进行评估。
单张X线片检测骨质溶解的总体敏感度为41.5%，总体特异度为93.0%。敏感度取决于病灶的位置和大小，但不取决于X线片视图。敏感度范围从髂骨病灶的72%到坐骨和髋臼缘病灶的≤¹⁵%。体积>10 cm³的病灶的检出率明显高于较小病灶（p<0.001）。当对一个病灶的所有四张X线片视图一起分析时，敏感度提高到73.6%。尽管敏感度较低，但特异度仍然很高，这表明一旦X线片上骨质溶解明显，病灶真正存在的可能性很高。此外，我们发现X线片对骨质溶解程度的估计严重不足。
使用X线片评估和监测骨质溶解既有局限性也有优点。使用多个视图，一位经验丰富的骨科医生仅识别出73.6%的骨盆病灶。然而，一旦骨盆骨质溶解病灶在X线片上明显，其真正存在的可能性很高。
