Gardner A W, Toh M Z, Yew K S A, Lie D T T, Chou S M
Department of Orthopaedic Surgery, Jurong Health Services, Alexandra Hospital, Singapore.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
J Orthop Surg (Hong Kong). 2015 Apr;23(1):41-6. doi: 10.1177/230949901502300110.
To compare the compressive strength of cannulated versus non-cannulated cancellous screws for undisplaced femoral neck fractures in synthetic bones.
18 synthetic proximal femurs simulating an AO B1 valgus impacted femoral neck fracture in osteoporotic bone were used. The fracture angles were between 55º and 63º (Pauwels grade 2). Fixation was made using 6.5-mm non-cannulated screws (n=6), 6.5-mm cannulated screws (n=6), or 7.3-mm cannulated screws (n=6). A custom-built jig was designed to guide the insertion of the screws in an identical triangular configuration. Screws were tightened by a single operator using a torque-measuring screwdriver. The femoral head was subjected to progressive axial loading at 5 mm/min. The load to failure and displacement were recorded.
The 3 groups did not differ significantly except that the load to failure was higher in the construct with 6.5-mm non-cannulated screws than that with 6.5-mm cannulated screws (1222 N vs 1008 N, p=0.003).
The compressive strength of a synthetic bone hip fracture model fixed with non-cannulated screws was higher than that of cannulated screws of the same diameter.
比较空心与非空心松质骨螺钉在合成骨中固定无移位股骨颈骨折的抗压强度。
使用18个模拟骨质疏松性骨中AO B1型外翻嵌插股骨颈骨折的合成近端股骨。骨折角度在55°至63°之间（Pauwels 2级）。分别使用6.5毫米非空心螺钉（n = 6）、6.5毫米空心螺钉（n = 6）或7.3毫米空心螺钉（n = 6）进行固定。设计了一个定制夹具，以相同的三角形配置引导螺钉插入。由一名操作员使用扭矩测量螺丝刀拧紧螺钉。以5毫米/分钟的速度对股骨头进行渐进轴向加载。记录破坏载荷和位移。
除6.5毫米非空心螺钉固定结构的破坏载荷高于6.5毫米空心螺钉固定结构（1222牛对1008牛，p = 0.003）外，三组之间无显著差异。
用非空心螺钉固定的合成骨髋部骨折模型的抗压强度高于相同直径的空心螺钉。
