Detecting cam-type deformities on plain radiographs: what is the optimal lateral view?
Detecting cam-type deformities on plain radiographs: what is the optimal lateral view?
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DOI：
10.1007/s00402-017-2793-9
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发表时间：
2017-12-01
影响因子：
2.3
通讯作者：
Domayer, Stephan
中科院分区：
文献类型：
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作者：
Hipfl, Christian;Titz, Markus;Domayer, Stephan
桡骨磁共振成像（MRI）是评估凸轮型股髋臼撞击最准确的诊断工具。然而，在日常实践中，平片对初步诊断是有用的，关于最佳侧位视图仍然存在争议。本研究的目的是通过与桡骨MRI进行比较，探讨使用蛙腿视图或45A度Dunn视图检测凸轮畸形的可靠性。通过x线平片（36例AP和青蛙腿视图，30例AP和45A度Dunn视图）和桡骨MRI对66个连续髋关节进行评估。两个研究者获得了x线片和径向MRI重新格式化的α角测量。统计包括频率分析、双变量线性相关分析和交叉表分析，测试x线摄影投影检测α角大于55A度的敏感性和特异性。类内相关显示两个评分者之间非常一致[ICC = 0.959， CI(0.943; 0.972)]。50%（33/66）的患者在股骨头颈交界处的上前方有最大的α角。桡骨MRI显示40/66例（61%）出现凸轮畸形。Pearson相关性显示，45A度Dunn位对上前位最准确（0.730,p < 0.05）。蛙腿视图最适合前部（0.703,p < 0.05）。在45A度Dunn视图中，检测凸轮畸形的灵敏度为84%，而在蛙腿视图中为62%。蛙腿侧位x线片不能提供可靠的α角测量。本研究强调了45A度Dunn角度对早期发现股髋臼凸轮型撞击的重要性。
Radial magnetic resonance imaging (MRI) is the most accurate diagnostic tool in assessing cam-type femoroacetabular impingement. Plain radiographs, however, are useful for the initial diagnosis in the daily practice and there is still debate regarding the optimal lateral view. The purpose of this study was to investigate the reliability of detecting cam deformities using the frog-leg view or the 45A degrees Dunn view by comparison with radial MRI.66 consecutive hips with plain radiographs (36 with AP and frog-leg views, 30 with AP and 45A degrees Dunn views) and radial MRI were assessed. Alpha angle measurements were obtained both for radiographs and for radial MRI reformats by two investigators. Statistics included frequency analysis, bivariate linear correlation analyses, and cross-table analyses testing the sensitivity and specificity of the radiographic projections for detecting an alpha angle larger than 55A degrees.The intra-class correlation revealed excellent agreement between the two raters [ICC = 0.959, CI (0.943; 0.972)]. 50% (33/66) had the maximum alpha angle in the superior-anterior aspect of the femoral head-neck junction. Cam deformity was found in 40/66 cases (61%) in radial MRI. Pearson correlation demonstrated that the 45A degrees Dunn view was most accurate for the superior-anterior aspect (0.730, p < 0.05). The frog-leg view was best suited for the anterior aspect (0.703, p < 0.05). The sensitivity for detecting cam deformities in the 45A degrees Dunn view was 84 vs 62% in the frog-leg view.The frog-leg lateral radiograph does not provide reliable measurements of the alpha angle. This study highlights the importance of the 45A degrees Dunn view for early detection of femoroacetabular cam-type impingement.