Deneka D A, Simonian P T, Stankewich C J, Eckert D, Chapman J R, Tencer A F
Department of Orthopaedic Surgery, Harborview Biomechanics Laboratory, University of Washington, Seattle, USA.
J Orthop Trauma. 1997 Jul;11(5):337-43. doi: 10.1097/00005131-199707000-00007.
The optimal method of internal fixation of basicervical femoral neck fractures is controversial. This area represents a transition zone between the intracapsular femoral neck fracture, usually fixed with multiple cancellous screws, and the extracapsular interochanteric fracture, fixed with a sliding screw device [sliding hip screw (SHS)] and derotation screw (DRS) device. The authors' specific aim was to biomechanically compare these two methods of fixation in a cadaveric model of a basicervical femoral neck fracture with posteromedial comminution.
The authors compared the average peak force during cyclic loading and the maximum axial force sustained by matched pairs of specimens stabilized with either fixation and subjected to axial and torsional loading while flexing and extending the hip. The average peak force was defined as the mean of the peak force values measured in each loading cycle with the maximum displacement of the materials tester actuator the same for each cycle (displacement control) as opposed to the maximum force being held constant (load control).
The cancellous screw group maintained a significantly lower average peak force, 470 Newtons (SD = 145 Newtons), compared with 868 Newtons (SD = 186 Newtons) for the SHS and DRS composite group (p < 0.01). Similarly, the cancellous screw group demonstrated a lower ultimate load to failure, 1,863 Newtons (SD = 475 Newtons) compared with 3,557 Newtons (SD = 215 Newtons) for the SHS and DRS composite group (p < 0.01).
The results support the use of an SHS and DHS composite compared with three cancellous screws in the treatment of unstable basicervical femoral neck fractures.
股骨颈基底部骨折的最佳内固定方法存在争议。该区域是囊内股骨颈骨折（通常用多根松质骨螺钉固定）与囊外粗隆间骨折（用滑动螺钉装置[动力髋螺钉（SHS）]和防旋螺钉（DRS）装置固定）之间的过渡区。作者的具体目的是在具有后内侧粉碎的股骨颈基底部骨折的尸体模型中，对这两种固定方法进行生物力学比较。
作者比较了在髋关节屈伸时，用两种固定方法固定的配对标本在循环加载过程中的平均峰值力以及承受的最大轴向力，同时对标本施加轴向和扭转载荷。平均峰值力定义为在每个加载循环中测量的峰值力值的平均值，材料试验机 actuator 的最大位移在每个循环中相同（位移控制），而不是最大力保持恒定（载荷控制）。
与 SHS 和 DRS复合组的868牛顿（标准差 = 186牛顿）相比，松质骨螺钉组的平均峰值力显著更低，为470牛顿（标准差 = 145牛顿）（p < 0.01）。同样，与SHS和DRS复合组的3557牛顿（标准差 = 215牛顿）相比，松质骨螺钉组的极限破坏载荷更低，为1863牛顿（标准差 = 475牛顿）（p < 0.01）。
结果支持在治疗不稳定的股骨颈基底部骨折时，与三根松质骨螺钉相比，使用SHS和DHS复合材料。
