Hadjari M H, Hollis J M, Hofmann O E, Flahiff C M, Nelson C L
Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock 72205.
Clin Orthop Relat Res. 1994 Oct(307):117-23.
The effects of screw location, screw tightness, acetabular bony defects, and implant size on the initial stability of porous coated acetabular implants was studied in vitro using 12 fresh frozen cadaver pelves. The fixation of porous coated acetabular implants was compared following fixation with either rim or center screws. Implants were tested first under axial and torsional stress. Then, either a peripheral or central bony defect was created in the acetabulum and testing was repeated in a similar fashion. Rim screws were noted to significantly improve the initial fixation of implants in intact acetabula and in acetabula with central bony defects. It was also shown that the tightness of the screws is an important factor affecting the strength of fixation. Although bony defects compromise the fixation of implants, specimens with central defects were very stable, particularly when tested with axial load. Acetabula with peripheral defects lost significant stability. The use of larger implants in acetabula with bony defects was shown to increase bony coverage and the overall implant stability.
使用12具新鲜冷冻尸体骨盆进行体外研究，以探讨螺钉位置、螺钉拧紧程度、髋臼骨缺损及植入物尺寸对多孔涂层髋臼植入物初始稳定性的影响。比较了使用边缘螺钉或中心螺钉固定后多孔涂层髋臼植入物的固定情况。首先在轴向和扭转应力下对植入物进行测试。然后，在髋臼中制造周边或中央骨缺损，并以类似方式重复测试。结果表明，边缘螺钉能显著提高植入物在完整髋臼及伴有中央骨缺损的髋臼中的初始固定。还表明，螺钉的拧紧程度是影响固定强度的一个重要因素。尽管骨缺损会损害植入物的固定，但有中央缺损的标本非常稳定，尤其是在轴向载荷测试时。有周边缺损的髋臼会显著丧失稳定性。研究显示，在有骨缺损的髋臼中使用更大尺寸的植入物可增加骨覆盖范围及整体植入物稳定性。
