The Discrepancy in the Posterior Boundary of Necrotic Lesion Between Axial and Oblique Axial Slices of MRI in Patients with Osteonecrosis of the Femoral Head
The Discrepancy in the Posterior Boundary of Necrotic Lesion Between Axial and Oblique Axial Slices of MRI in Patients with Osteonecrosis of the Femoral Head
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DOI：
10.2106/jbjs.20.00493
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发表时间：
2022-04-06
影响因子：
5.3
通讯作者：
Nakashima, Yasuharu
中科院分区：
文献类型：
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作者：
Ikemura, Satoshi;Motomura, Goro;Nakashima, Yasuharu
背景：磁共振成像(MRI)对股骨头前后位骨质坏死性病变(ONFH)在与体轴平行的轴面(轴)和平行于股骨颈轴线的轴面(斜轴)之间的评估差异鲜为人知。本研究旨在比较轴位和斜位轴位平面上坏死性病变的后界。方法：本研究回顾了71例ONFH患者的120个连续髋关节，男47例，女24例，平均年龄42岁，均有轴位和斜位MRI切片。用中轴位和中斜位轴位MRI切片计算坏死灶的后界，即股骨头后完整周长与股骨头前后周长的比值。用改良的Kerbul法计算的坏死角在塌陷进展和无进展的病例中进行了比较。结果：轴位层面后方完好率为49.2%(8.6~85.1%)，斜位层面后方完好率为33.5%(7.5~79.2%)。与轴位相比，斜位轴位后方完好率显著降低(p<；0.0001)。在塌陷进展的病例中，斜轴位的平均坏死角显著大于轴位的(p<；0.0001)。倾斜轴位扫描对股骨头坏死角度判断预后的敏感性和特异度均高于轴位扫描(敏感度：88.4%，特异度：82.3%)。中轴位上方平均6.8 mm处的后方完好率与中斜位的后位完好率相当。结论：轴位和斜位轴位扫描显示股骨头坏死病变的后界不同，斜位轴位MRI检查可能更适用于预测股骨头的预后。
Background: Little is known concerning differences in assessment of anteroposterior osteonecrotic lesion of the femoral head (ONFH) between the axial plane parallel to the body axis (axial) and the axial plane parallel to the femoral neck axis (oblique axial) using magnetic resonance imaging (MRI). This study aimed to compare the posterior boundary of necrotic lesions between the axial and oblique axial planes on MRI. Methods: This study retrospectively reviewed 120 consecutive hips in 71 patients (47 males and 24 females; mean age, 42 years) with ONFH, for which both axial and oblique axial MRI slices were available. The posterior boundaries of the necrotic lesions were calculated as the ratio of posterior intact circumference to anteroposterior circumference of the femoral head using mid-axial and mid-oblique axial MRI slices. The necrotic angles, calculated using the modified Kerboul method, were compared between cases with progression and nonprogression of collapse. Results: The mean posterior intact ratio in the axial slice was 49.2% (range, 8.6 to 85.1%), while that in the oblique axial slice was 33.5% (7.5 to 79.2%). The posterior intact ratio in the oblique axial slice significantly decreased compared to that in the axial slice (p < 0.0001). In cases with progression of collapse, the mean necrotic angle was significantly larger in the oblique axial slice than in the axial slice (p < 0.0001). The sensitivity and specificity of the necrotic angle with regard to the prognosis of the femoral head were both higher when using the oblique axial slice (sensitivity: 88.4%, specificity: 82.3%) than when using the axial slice (sensitivity: 85.1%, specificity: 62.0%). The posterior intact ratio at a mean of 6.8 mm superior to the mid-axial slice corresponded to that of the mid-oblique axial slice. Conclusion: Our findings suggest that the posterior boundaries of necrotic lesions differ between axial and oblique axial slices, and examination of the oblique axial MRI slice might be more suitable for predicting the prognosis of the femoral head.