Shea M, Wittenberg R H, Edwards W T, White A A, Hayes W C
Department of Orthopaedic Surgery, Charles A. Dana Research Institute, Beth Israel Hospital, Boston, Massachusetts 02215.
J Orthop Res. 1992 Nov;10(6):911-6. doi: 10.1002/jor.1100100621.
To investigate the relationship between the type of hyperextension injuries and the conditions producing them, nine cervical specimens (occiput to T1) were loaded to failure in tension at a fixed extension angle of 30 degrees. Under these loading conditions, specimens failed at average tensile loads and extension moments of 499 +/- 148 (SD) N and 4.0 +/- 3.1 Nm, respectively. Failure occurred at an average tensile displacement of 18.8 +/- 7.7 mm. The anterior longitudinal ligament ruptured and the intervertebral disc failed in at least one level in all specimens. In four specimens, the disc failed at an additional level, leaving the anterior longitudinal ligament intact at that site. With one exception, all injuries occurred in the lower cervical spine (C5-C6 and C6-C7), the region most often injured in vivo. The location of the injuries was associated with the degree of degeneration of the facet joints and the discs. The discs of the lower cervical spine were significantly more degenerated than those at the C2-C3 level. In addition, the degree of disc degeneration in the noninjured discs was significantly less than in the injured discs. These data help quantify the threshold of injury and the patterns of tissue damage resulting from hypertension loading of the cervical spine.
为了研究过伸性损伤的类型与导致这些损伤的条件之间的关系，对九个颈椎标本（枕骨至T1）在30度的固定伸展角度下进行拉伸直至破坏。在这些加载条件下，标本分别在平均拉伸载荷499±148（标准差）N和伸展力矩4.0±3.1 Nm时破坏。破坏发生时的平均拉伸位移为18.8±7.7 mm。所有标本中，前纵韧带均断裂，且至少有一个节段的椎间盘失效。在四个标本中，另一个节段的椎间盘失效，而该部位的前纵韧带保持完整。除一例例外，所有损伤均发生在下颈椎（C5-C6和C6-C7），这是体内最常受伤的区域。损伤的位置与小关节和椎间盘的退变程度有关。下颈椎的椎间盘退变程度明显高于C2-C3节段。此外，未受伤椎间盘的退变程度明显低于受伤椎间盘。这些数据有助于量化颈椎过伸加载导致损伤的阈值和组织损伤模式。
