Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA.
Orthop Surg. 2013 May;5(2):94-9. doi: 10.1111/os.12034.
The Rule of Spence states that displacement of the C₁ lateral masses by >6.9-8.1 mm suggests loss of transverse ligament integrity. The purpose of this study was to establish the thresholds of C₁ displacement on CT scans that correspond to transverse ligament disruption.
Over four years, consecutive patients with acute C₁ fractures with at least three fracture lines were analyzed. CT measurements and MRI were assessed by blinded observers for bony displacement in the axial (internal and external lateral mass separation), coronal and sagittal planes and transverse ligament integrity.
Eighteen patients were studied. Mean CT bony measurements were as follows: internal border lateral mass separation (ILM) 23.3 ± 3.4 mm, external border lateral mass separation (ELM) 50.3 ± 4.3 mm, total C₁ lateral mass overhang over the C₂ superior process (LMO) 5.4 ± 1.3 mm. Twelve patients were identified as having intact transverse ligament and six had transverse ligament disruption. There was no difference in mean normalized ILM, ELM, or LMO between patients with or without transverse ligament integrity (P > 0.05).
There was no correlation between bony displacement and transverse ligament integrity. CT scans post-injury may not show the position of maximal displacement. If there is clinical concern about a possible transverse ligament injury, MRI should be performed.
斯宾塞定则指出，C₁侧块的移位>6.9-8.1mm 提示横韧带完整性丧失。本研究旨在确定 CT 扫描上与横韧带断裂相对应的 C₁ 位移阈值。
在四年多的时间里，对至少有三条骨折线的急性 C₁ 骨折的连续患者进行了分析。通过盲法观察者评估 CT 测量值和 MRI 来评估轴向（内侧和外侧侧块分离）、冠状和矢状平面以及横韧带完整性的骨移位。
研究了 18 名患者。CT 骨测量的平均值如下：内侧边界侧块分离（ILM）23.3±3.4mm，外侧边界侧块分离（ELM）50.3±4.3mm，C₁ 侧块总突出超过 C₂ 上突（LMO）5.4±1.3mm。12 名患者被确定为横韧带完整，6 名患者横韧带断裂。在横韧带完整或不完整的患者之间，平均归一化 ILM、ELM 或 LMO 没有差异（P>0.05）。
骨移位与横韧带完整性之间没有相关性。损伤后的 CT 扫描可能无法显示最大位移的位置。如果临床怀疑可能存在横韧带损伤，应进行 MRI 检查。
