Department of Radiology, New York University Hospital for Joint Diseases, 301 E 17th St, 6th Fl, New York, NY 10003-3899, USA.
AJR Am J Roentgenol. 2011 Oct;197(4):954-60. doi: 10.2214/AJR.10.6262.
The objective of our study was to evaluate the diagnostic utility of conventional radiography for diagnosing bisphosphonate-related atypical subtrochanteric femoral fractures.
Retrospective interpretation of 38 radiographs of complete subtrochanteric and diaphyseal femoral fractures in two patient groups-one group being treated with bisphosphonates (19 fractures in 17 patients) and a second group not being treated with bisphosphonates (19 fractures in 19 patients)-was performed by three radiologists. The readers assessed four imaging criteria: focal lateral cortical thickening, transverse fracture, medial femoral spike, and fracture comminution. The odds ratios and the sensitivity, specificity, and accuracy of each imaging criterion as a predictor of bisphosphonate-related fractures were calculated. Similarly, the interobserver agreement and the sensitivity, specificity, and accuracy of diagnosing bisphosphonate-related fractures (i.e., atypical femoral fractures) were determined for the three readers.
Among the candidate predictors of bisphosphonate-related fractures, focal lateral cortical thickening and transverse fracture had the highest odds ratios (76.4 and 10.1, respectively). Medial spike and comminution had odd ratios of 3.8 and 0.63, respectively. Focal lateral cortical thickening and transverse fracture were also the most accurate factors for detecting bisphosphonate-related fractures for all readers. The sensitivity, specificity, and overall accuracy for diagnosing bisphosphonate-related fractures were 94.7%, 100%, and 97.4% for reader 1; 94.7%, 68.4%, and 81.6% for reader 2; and 89.5%, 89.5%, and 89.5% for reader 3, respectively. The interobserver agreement was substantial (κ > 0.61).
Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures.
我们的研究目的是评估常规放射摄影术在诊断双膦酸盐相关性非典型转子下股骨骨折中的诊断效用。
对两组患者的 38 张完整转子下和股骨干骨折的 X 线片进行回顾性解读，一组为接受双膦酸盐治疗的患者（17 名患者中的 19 处骨折），另一组为未接受双膦酸盐治疗的患者（19 名患者中的 19 处骨折）。三位放射科医生对四个影像学标准进行评估：局部外侧皮质增厚、横向骨折、内侧股骨刺突和骨折粉碎。计算每个影像学标准作为双膦酸盐相关性骨折预测指标的优势比，以及灵敏度、特异性和准确性。同样，确定三位读者诊断双膦酸盐相关性骨折（即非典型股骨骨折）的观察者间一致性以及灵敏度、特异性和准确性。
在双膦酸盐相关性骨折的候选预测指标中，局部外侧皮质增厚和横向骨折的优势比最高（分别为 76.4 和 10.1）。内侧刺突和粉碎的优势比分别为 3.8 和 0.63。对于所有读者，局部外侧皮质增厚和横向骨折也是检测双膦酸盐相关性骨折最准确的因素。诊断双膦酸盐相关性骨折的灵敏度、特异性和总准确率为读者 1 为 94.7%、100%和 97.4%；读者 2 为 94.7%、68.4%和 81.6%；读者 3 为 89.5%、89.5%和 89.5%。观察者间的一致性很高（κ＞0.61）。
X 线片可可靠地区分与双膦酸盐使用相关的完整股骨骨折与不相关的股骨骨折。局部外侧皮质增厚和横向骨折是最可靠的征象，具有较高的优势比和诊断这些骨折的最高准确性。
