髂骨螺钉松动四种翻修技术的生物力学比较  

Biomechanical test of 4 revision techniques for loosened iliac screw

作　　者：于滨生[1] 庄新明[1] 李泽民[1] 郑召民[1] 王泰平[1] 

机构地区：[1]中山大学附属第一医院脊柱外科骨科研究所,广州市黄埔东路183号510700

出　　处：《中国脊柱脊髓杂志》2010年第4期272-276,共5页Chinese Journal of Spine and Spinal Cord

基　　金：广东省科技计划项目(2008B050100012和2009B050700023)

摘　　要：目的:比较松质骨填塞钉道、增加螺钉长度、传统聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)强化钉道和外板开窗PMMA强化钉道四种方法翻修松动髂骨螺钉后的固定强度,探讨髂骨螺钉松动的理想补救手段。方法:8具成人防腐尸体骨盆标本,经双能X光吸收法测定骨密度后,将直径7.5mm髂骨短钉(长度为70mm)分别置入左右髂骨(A组),通过MTS材料实验机向螺钉尾部施加100～300N垂直循环载荷2000次后,测试髂骨螺钉的轴向拔出力。用松质骨紧密填塞两侧钉道后,在左侧钉道内置入短钉(B组),右侧钉道置入长度为100mm的髂骨长钉(C组),重复上述测试。将左侧钉道内注满PMMA后,再次置入髂骨短钉(D组);将另1枚髂骨短钉置入右侧钉道,以螺钉中点为中心沿螺钉轴线的髂骨外板处开窗,高度20mm、长度40mm、深度至内板皮质,灌注PMMA(E组);D组和E组重复上述测试。记录各组髂骨螺钉的轴向最大拔出力并进行比较。结果:8具标本的骨密度为0.75～0.91g/cm2,平均为0.85±0.05g/cm2。A～E组的最大拔出力分别为1174±542N、261±89N、769±317N、1954±623N和1820±659N,D组与E组比较无显著性差异(P>0.05),D组与E组显著高于A、B和C组(P<0.05),C组显著高于B组(P<0.05),B组和C组显著低于A组(P<0.05)。结论:松质骨填塞钉道和增加螺钉长度不能恢复髂骨螺钉的锚定强度;外板开窗PMMA强化和传统PMMA强化后置钉可使髂骨螺钉获得更高的锚定强度;从微创角度,外板开窗PMMA强化可能成为髂骨螺钉松动的理想补救手段。Objective：To compare 4 revision techniques in terms of stuffing cancellous bone,increasing screw length,traditional polymethylmethacrylate（PMMA） augmentation and outer cortical window PMMA augmentation for the salvage of loosened iliac screw,and to determine the favorable protocol.Method：8 preserved human cadaver pelvis were used in this study.After measuring bone mineral density（BMD） by dual-energy radiograph absorptiometry,7.5mm diameter and 70mm length iliac screws were inserted into bilateral side of ilium（group A）.2000 cyclic of 100-300N compressive loading was added to the screw tail,the axial pull-out strength of iliac screw were measured on a MTS material testing machine.After stuffing the two screw path with cancellous bone,the iliac screw with same length was reinserted into the left side（group B） and another iliac screw with the length of 100mm was placed in the right side（group C）.The test mentioned above was repeated,and then the left screw path was filled with PMMA and 70mm length iliac screw was inserted（group D）.Another 70mm length screw was inserted into the right side,and an outer cortical window with 40mm length,20mm height,depth to the inner cortical bone was made around the screw center and filled up with PMMA（group E）.Lastly,the PMMA augmented screws were retested as before.The maximum pull-out strengths of the five screwing techniques were measured and compared biomechanically.Result：The average BMD value of 8 specimens was 0.85±0.05g/cm^2,ranged from 0.75 to 0.91g/cm^2.The maximum pull-out strengths for group A-E were 1174±542N,261±89N,769±317N,1954±623N and 1820 ±659N respectively.No significant difference with respect to maximum pull-out strength was noted between group D and E（P〉0.05）,however,the two PMMA aug mented techniques provided obviously higher maximum pull-out strength than those in group A,B and C（P〈0.05）.Although group C showed markedly higher maximum pull-out strength than group B（P〈0.05）,significantly lower maximum p

关 键 词：腰骶融合 髂骨螺钉固定 螺钉松动 翻修 聚甲基丙烯酸甲酯 生物力学 

分 类 号：R687.3[医药卫生—骨科学] R318.01[医药卫生—外科学]