Leeds Musculoskeletal Biomedical Research Unit, Chapel Allerton Hospital, Leeds, UK.
AJR Am J Roentgenol. 2012 Apr;198(4):W365-9. doi: 10.2214/AJR.11.7222.
The purpose of this study is to determine the diagnostic accuracy of radiographs in the diagnosis of Lisfranc injury. In addition, a foot phantom was investigated to determine the optimum degree of craniocaudal angulation on the anteroposterior radiograph to best show the joint. The angle of the joint in patients with midfoot injury was investigated to determine the optimum degree of craniocaudal angulation.
Sixty patients examined by CT had their radiographs evaluated independently and by consensus opinion by two observers, and the diagnostic performance was calculated using CT as the reference standard. A foot phantom was radiographed with varying degrees of craniocaudal angulation, and the radiograph that best revealed the joint was determined. This was compared with the angle of the joint as measured on CT. The angle of the joint in all 60 patients was measured on CT.
The radiographs correctly identified 31 of the 45 cases (68.9%) of Lisfranc injury, with a positive predictive value of 84.4%, a negative predictive value of 53.3%, a sensitivity of 84.4%, and a specificity of 53.3%. Twenty degrees of craniocaudal angulation best showed the second tarsal-metatarsal joint of the phantom, and this correlated with a 20° angle measured by CT. The mean (± SD) angle of the joint in the patients was 28.9° ± 5.7°.
Conventional radiographs miss a significant number of cases of Lisfranc injury. Craniocaudal angulation can better show the joint, and an angle of 28.9° is likely to optimally visualize the joint in the majority of patients.
本研究旨在确定 X 线在诊断 Lisfranc 损伤中的诊断准确性。此外，还研究了足模拟体，以确定前后位 X 线片上最佳的头尾向倾斜角度，以最佳显示关节。研究了中足损伤患者的关节角度，以确定最佳的头尾向倾斜角度。
对 60 例经 CT 检查的患者进行 X 线片独立评估和两位观察者的共识评估，并使用 CT 作为参考标准计算诊断性能。对足模拟体进行不同头尾向倾斜角度的 X 线摄影，确定最佳显示关节的 X 线片。并与 CT 上测量的关节角度进行比较。对所有 60 例患者的 CT 上的关节角度进行测量。
X 线片正确识别出 45 例 Lisfranc 损伤中的 31 例（68.9%），阳性预测值为 84.4%，阴性预测值为 53.3%，敏感性为 84.4%，特异性为 53.3%。20°的头尾向倾斜角度最佳显示模拟体的第二跗跖关节，这与 CT 测量的 20°角度相关。患者关节的平均（± SD）角度为 28.9°±5.7°。
常规 X 线片漏诊了相当数量的 Lisfranc 损伤病例。头尾向倾斜可以更好地显示关节，大多数患者的 28.9°角度可能是最佳的关节可视化角度。
