骶骨椎弓根钉松动后的骨水泥强化技术选择  

CHOICE OF BONE CEMENT AUGMENTATION TECHNIQUES WHEN SACRAL PEDICLE SCREW LOOSENING

作　　者：于滨生[1] 庄新明[1] 李泽民[1] 郑召民[1] 

机构地区：[1]中山大学附属第一医院脊柱外科,广州510700

出　　处：《中国修复重建外科杂志》2010年第2期211-214,共4页Chinese Journal of Reparative and Reconstructive Surgery

基　　金：广东省科技计划重点资助项目(2008B050100012)~~

摘　　要：目的在骨质疏松骶骨标本上,对2种椎弓根钉和3种聚甲基丙烯酸甲酯骨水泥(poly methylmethacrylate,PMMA)强化骶骨钉的最大拔出力进行生物力学比较,以期明确何种PMMA强化技术可作为骶骨椎弓根钉松动后理想的补救手段。方法取自愿捐赠的新鲜成人尸体完整骶骨标本11个。其中男5个,女6个;年龄66～83岁,平均74.4岁。X线片排除肿瘤、炎症及解剖学变异。经骨密度测试后,在同一骶骨标本上,依次建立5种骶骨钉固定模型,分别为单皮质椎弓根钉(A组)、双皮质椎弓根钉(B组)、PMMA钉道强化单皮质椎弓根钉(C组)、PMMA钉道强化侧翼钉(D组)和后凸成形技术支持下的PMMA强化侧翼钉(E组)。根据螺钉植入顺序用MTS-858材料试验机行轴向拔出力测试,记录并比较各组最大拔出力,对拔出后PMMA强化螺钉行大体观察。结果11个标本的骨密度值为(0.71±0.08)g/cm2,均为骨质疏松标本。螺钉拔出后大体观察可见,C、D、E组螺钉与PMMA结合良好,其中E组较C、D组结合更多PMMA。A～E组最大拔出力分别为(508±128)、(685±126)、(846±230)、(543±121)、(702±144)N,B、C、E组最大拔出力大于A、D组(P<0.05),B、E组小于C组(P<0.05),A、D组间及B、E组间比较差异均无统计学意义(P>0.05)。结论对骨密度>0.7g/cm2的骨质疏松患者行骶骨固定时,双皮质骶骨椎弓根钉较单皮质具有更高的固定强度。骶骨椎弓根钉一旦发生松动,PMMA钉道强化和后凸成形技术支持下的PMMA强化侧翼钉均可成为理想的补救手段。Objective To biomechanically compare the maximum pull-out strengths among two pedicle screws and three salvage techniques using poly methylmethacrylate（PMMA）augmentation in osteoporotic sacrum,and to determine which PMMA augmentation technique could serve as the salvage fixation for loosening sacral pedicle screws.Methods Eleven sacra were harvested from fresh adult donated cadavers,aged from 66 to 83 years（average 74.4 years）and included 5 men and 6 women.Radiography was used to exclude sacra that showed tumor or inflammatory or any other anatomic abnormalities.Following the measurement of bone mineral density,five sacral screw fixations were sequentially established on the same sacrum as follows：unicortical pedicle screw（group A）,bicortical pedicle screw（group B）,unicortical pedicle screw with the traditional PMMA augmentation（group C）,ala screw with the traditional PMMA augmentation（group D）,and ala screw with a kyphoplasty-assisted PMMA augmentation technique（group E）.According to the sequence above,the axial pull-out test of each screw was conducted on a MTS-858 material testing machine.The maximum pull-out forces were measured and compared.The morphologies of PMMA augmented screws after being pulled-out were also inspected.Results The average bone mineral density of 11 osteoporotic specimens was（0.71±0.08）g/cm2.By observation of the pull-out screws,groups C,D,E showed perfect bonding with PMMA,and group E bonded more PMMA than groups C and D.The maximum pull-out forces of groups A,B,C,D,and E were（508±128）,（685±126）,（846±230）,（543±121）,and（702±144）N,respectively.The maximum pull-out strength was significantly higher in groups B,C,and E than in groups A and D（P0.05）,and in group C than in groups B and E（P0.05）.There was no significant difference in pull-out strength between groups A and D,and between groups B and E（P0.05）.Conclusion For sacral screw fixation of osteoporotic patients with bone mineral density more than 0.7 g/cm2,bicortica

关 键 词：骨质疏松 腰骶融合 骶骨椎弓根钉 骨水泥强化 生物力学 

分 类 号：R687.3[医药卫生—骨科学]