A BIOMECHANICAL EVALUATION OF THE GAMMA-NAIL
A BIOMECHANICAL EVALUATION OF THE GAMMA-NAIL
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DOI：
10.1302/0301-620x.74b3.1587875
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发表时间：
1992-05-01
影响因子：
--
通讯作者：
TAM, BS
中科院分区：
文献类型：
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作者：
ROSENBLUM, SF;ZUCKERMAN, JD;TAM, BS
我们使用10具尸体股骨，沿内侧和外侧皮质沿着6个单向应变计，检查Gamma髓内钉对股骨近端应变分布的影响。股骨被加载到1800 N，并在实验创建的两部分和四部分骨折之前和之后，使用或不使用远端交锁螺钉确定应变。还确定了滑动螺钉和髓内钉的运动。应变模式和螺钉运动与先前获得的滑动髋螺钉装置（SHS）的值进行了比较。Gamma钉显示出随着骨折稳定性的降低，向股骨距传递的载荷逐渐减少，因此，在后内侧骨折块取出的四部分骨折中，几乎没有观察到骨应变;但是，在近端外侧皮质处观察到压力增加。相反，SHS显示股骨距压缩增加，骨折稳定性降低。远端交锁螺钉的插入并没有改变股骨近端的应变模式，Gamma髓内钉对股骨近端施加了非生理应变，可能是由于其固有的刚度。这些菌株可能会改变骨重建和干扰愈合。对于稳定型股骨转子间骨折，可能不需要远端交锁螺钉。
We examined the effect of the Gamma nail on strain distribution in the proximal femur, using ten cadaver femora instrumented with six unidirectional strain gauges along the medial and lateral cortices. The femora were loaded to 1800 N and strains were determined with or without distal interlocking screws before and after experimentally created two-part and four-part fractures. Motion of the sliding screw and the nail was also determined. Strain patterns and screw motion were compared with previously obtained values for a sliding hip screw device (SHS).The Gamma nail was shown to transmit decreasing load to the calcar with decreasing fracture stability, such that virtually no strain on the bone was seen in four-part fractures with the posteromedial fragment removed; increasing compression was noted, however, at the proximal lateral cortex. Conversely, the SHS showed increased calcar compression with decreasing fracture stability. The insertion of distal interlocking screws did not change the pattern of proximal femoral strain.The Gamma nail imparts non-physiological strains to the proximal femur, probably because of its inherent stiffness. These strains may alter bone remodelling and interfere with healing. Distal interlocking screws may not be necessary for stable intertrochanteric fractures.