髋臼后壁骨折三种内固定方式的生物力学研究及临床意义

背景：锁定重建接骨板已应用于髋臼后壁骨折的治疗，但关于其固定髋臼后壁骨折生物力学稳定性的研究报道甚少。目的：比较锁定重建接骨板、重建接骨板及单纯拉力螺钉固定髋臼后壁骨折的生物力学稳定性。 方法：取成人新鲜半骨盆标本18个，制成髋臼后壁骨折模型，随机分成三组。A组用2枚拉力螺钉固定，B组用重建接骨板固定，C组用锁定重建接骨板固定。进行轴向加载实验，测定各组骨折的纵向位移、内固定失效时的载荷及轴向刚度，以比较各内固定方式的稳定性。 结果：在相同载荷下，B组、C组骨折的纵向位移小于A组，B组、C组内固定失效时的载荷及轴向刚度大于A组，有统计学差异（P＜0.05）；B组与C组在纵向位移、内固定失效时的载荷及轴向刚度之间无统计学差异（P＞0.05）。 结论：锁定重建接骨板与重建接骨板的内固定稳定性优于单纯拉力螺钉内固定，锁定重建接骨板与重建接骨板内的固定稳定性相似，均可用于髋臼后壁骨折的内固定治疗。

Biomechanical study on three internal fixation methods for acetabular posterior wall fractures

Background：Locking reconstruction plates have been used to treat acetabular posterior wall fractures. But there are few re-ports on the biomechanic stability of acetabular posterior wall fractures fixed with locking reconstruction plate. Objective： To compare the biomechanic stability of acetabular posterior wall fractures fixed with locking reconstruction plate, reconstruction plate or lag screw. Methods： Acetabular posterior wall fractures were induced in 18 adult fresh semipelvis specimens, and then divided into three groups randomly. The fractures were fixed with two lag screws in group A, with reconstruction plate in group B, and with locking reconstruction plate in group C. The longitudinal displacements, loading of failed internal fixation and axial stiffness were measured by axial loading experiments and compared between groups. Results：Under the same loading, longitudinal displacements of group B and C were shorter than that of group A （P＆lt;0.05）. The maximum load and axial stiffness of group B and C were larger than those of group A （P＆lt;0.05）. However, there were no significant differences in the longitudinal displacements, loading of failed internal fixation and axis stiffness between group B and C （P＆gt;0.05）. Conclusions：For the acetabular posterior wall fractures, locking reconstruction plate and reconstruction plate internal fixa-tion can provide greater stability than simple lag screws. And the biomechanic stability of internal fixation with locking re-construction plate is similar to reconstruction plate. They can be used for internal fixation management of the posterior wall acetabular fractures.