Raynor R B, Carter F W
Department of Neurosurgery, St. Vincent's Hospital, New York, New York.
Spine (Phila Pa 1976). 1991 Oct;16(10 Suppl):S558-60. doi: 10.1097/00007632-199110001-00021.
Although metallic plates are used for cervical spine stabilization, few biomechanical studies have been done to evaluate their efficiency. A previous study indicated that one half of the facet joint may be destroyed before compromise in strength occurs. Isolated motion segments in which one half of the facet joint was resected bilaterally were used. A two-hole Roy-Camille plate was attached bilaterally with 3.5-mm-diameter, 16-mm-long screws and the construct loaded in shear. Failure occurred at 415.6 N by fracture through the screw holes of the damaged joint, compared to a failure load of 699.6 N in specimens without screws and plates but in which 75% of the joint had been destroyed. Results were significant at the 95% confidence level. A second group of specimens using C2-3-4 and C5-6-7 was tested after 50% facet resection and application of a three-segment plate. Failure again occurred by fracture through the screw hole at the damaged joint. We conclude that, if significant facet destruction is present, screw holes for plate application further weakens the bone. The desired biomechanical stability may not be present.
尽管金属板用于颈椎稳定，但很少有生物力学研究来评估其有效性。先前的一项研究表明，在强度受损之前，小关节的一半可能已被破坏。使用双侧小关节一半被切除的孤立运动节段。双侧用直径3.5毫米、长16毫米的螺钉安装两孔Roy-Camille钢板，并对该结构施加剪切载荷。通过受损关节的螺钉孔骨折，在415.6 N时发生失效，而在没有螺钉和钢板但75%的关节已被破坏的标本中，失效载荷为699.6 N。结果在95%置信水平上具有显著性。第二组使用C2-3-4和C5-6-7的标本在50%小关节切除并应用三段钢板后进行测试。同样通过受损关节的螺钉孔骨折发生失效。我们得出结论，如果存在明显的小关节破坏，用于钢板固定的螺钉孔会进一步削弱骨骼。可能不存在所需的生物力学稳定性。
