CAJ | 학술논문

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/cm~2,平均为0.85±0.05g/cm~2.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.
목적:비교송질골전새정도、증가라정장도、전통취갑기병희산갑지(polymethylmethacrylate,PMMA)강화정도화외판개창PMMA강화정도사충방법번수송동가골라정후적고정강도,탐토가골라정송동적이상보구수단.방법:8구성인방부시체골분표본,경쌍능X광흡수법측정골밀도후,장직경7.5mm가골단정(장도위70mm)분별치입좌우가골(A조),통과MTS재료실험궤향라정미부시가100～300N수직순배재하2000차후,측시가골라정적축향발출력.용송질골긴밀전새량측정도후,재좌측정도내치입단정(B조),우측정도치입장도위100mm적가골장정(C조),중복상술측시.장좌측정도내주만PMMA후,재차치입가골단정(D조);장령1매가골단정치입우측정도,이라정중점위중심연라정축선적가골외판처개창,고도20mm、장도40mm、심도지내판피질,관주PMMA(E조);D조화E조중복상술측시.기록각조가골라정적축향최대발출력병진행비교.결과:8구표본적골밀도위0.75～0.91g/cm~2,평균위0.85±0.05g/cm~2.A～E조적최대발출력분별위1174±542N、261±89N、769±317N、1954±623N화1820±659N,D조여E조비교무현저성차이(P>0.05),D조여E조현저고우A、B화C조(P<0.05),C조현저고우B조(P<0.05),B조화C조현저저우A조(P<0.05).결론:송질골전새정도화증가라정장도불능회복가골라정적묘정강도;외판개창PMMA강화화전통PMMA강화후치정가사가골라정획득경고적묘정강도;종미창각도,외판개창PMMA강화가능성위가골라정송동적이상보구수단.
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 augmented 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 pull-out strength was documented in group B and C than that in group A(P<0.05).Conclusion:Stuffing cancellous bone and increasing screw length can not afford the anchoring strength of iliac screw;while the traditional and opening window PMMA augmentation are capacitated to improve iliac screw fixation strength effectively.Based on minimal invasive prospect,outer cortical window PMMA augmentation may serve as an ideal salvage technique for loosened iliac screw.