CAJ | 학술논문

目的：评价重度骨质疏松条件下椎弓根螺钉的稳定性，为椎弓根内固定在合并有重度骨质疏松症的患者中的选用提供力学理论基础。方法采用新鲜尸体脊柱标本，检测骨密度后，根据诊断标准，选用正常骨质的2具尸体标本、重度骨质疏松的4具尸体标本，分离T12～L5节段成单个椎体以备后用；然后在骨质正常椎体置入椎弓根螺钉12枚作对照组；在重度骨质疏松水平，分单纯置入椎弓根螺钉（ pedicle screw，PS）、经磷酸钙骨水泥（ calcium phos-phate cement，CPC）强化钉道后置入椎弓根螺钉、经聚甲基丙烯酸甲酯（ polymethylmethacrylate，PMMA）强化钉道后置入椎弓根螺钉三种方法置钉，依次为PS组、CPC/PS组和PMMA/PS组，进行螺钉轴向拔出实验，测最大拔出力、刚度和能量吸收值，对所测指标进行组间对比分析。结果重度疏松条件下，PS组、CPC/PS组和PMMA/PS各组最大拔出力、刚度、能量吸收值均显著低于对照组（ P<0.005）；但是，PMMA/PS组三项指标均显著高于PS组、CPC/PS组（ P<0.001）；PS组、CPC/PS组之间比较仅最大拔出力存在显著性差异（ P<0.05），刚度与能量吸收值差异无统计学意义（P>0.05）。结论重度骨质疏松条件下，椎弓根螺钉固定强度明显下降，不宜单纯应用普通椎弓根螺钉行脊柱内固定治疗，采用普通骨水泥强化钉道后置钉可以提高椎弓根螺钉稳定性。
목적：평개중도골질소송조건하추궁근라정적은정성，위추궁근내고정재합병유중도골질소송증적환자중적선용제공역학이론기출。방법채용신선시체척주표본，검측골밀도후，근거진단표준，선용정상골질적2구시체표본、중도골질소송적4구시체표본，분리T12～L5절단성단개추체이비후용；연후재골질정상추체치입추궁근라정12매작대조조；재중도골질소송수평，분단순치입추궁근라정（ pedicle screw，PS）、경린산개골수니（ calcium phos-phate cement，CPC）강화정도후치입추궁근라정、경취갑기병희산갑지（ polymethylmethacrylate，PMMA）강화정도후치입추궁근라정삼충방법치정，의차위PS조、CPC/PS조화PMMA/PS조，진행라정축향발출실험，측최대발출력、강도화능량흡수치，대소측지표진행조간대비분석。결과중도소송조건하，PS조、CPC/PS조화PMMA/PS각조최대발출력、강도、능량흡수치균현저저우대조조（ P<0.005）；단시，PMMA/PS조삼항지표균현저고우PS조、CPC/PS조（ P<0.001）；PS조、CPC/PS조지간비교부최대발출력존재현저성차이（ P<0.05），강도여능량흡수치차이무통계학의의（P>0.05）。결론중도골질소송조건하，추궁근라정고정강도명현하강，불의단순응용보통추궁근라정행척주내고정치료，채용보통골수니강화정도후치정가이제고추궁근라정은정성。
Objective To evaluate the fixation of pedicle screw in the lumbar spine with severe osteoporosis,further to provide theoretical evidence for clinical application of pedicle screw in patient with severe osteoporosis. Methods Fresh hu-man cadaver spines were used. Two of them were normal and four were severe osteoporosis,according to the value of bone min-eral density. The vertebra was bilaterally instrumented pedicle screws,resulting in 24 screws in normal BMD group,as the con-trol group. The vertebrae at severe osteoporosis level was bilaterally instrumented with pedicle screws according to three proto-cols,including pedicle screw without augmentation,pedicle screw with calcium phosphate cement( CPC)augmentation,pedicle screw with poly( methyl methacrylate)( PMMA)augmentation,as group PS,group CPC/PS and group PMMA/PS,respectively. Sixteen pedicles per protocol were obtained in each group. Screw pullout tests were conducted. On the load-stroke curve,the maximum pullout strength,stiffness and energy absorption were determined. The differences between groups were compared. Results With the BMD decreasing in severe osteoporosis level,the maximum pullout strength,the stiffness and the absorbed energy of pedicle screw were correspondingly significantly lower than those of the control group(P<0. 005). Also,the above three indexes of PMMA/PS group were significantly higher than those of PS and CPC/PS group(P<0. 001),but no signifi-cance difference was found between PS and CPC/PS group in these indexes(P>0. 05)except but the pullout strength(P<0. 05). Conclusion Under the condition of severe osteoporosis,the purchase strength of pedicle screw decreases significantly,it should not be used alone in the spine surgery of internal fixation. After being augmented with PMMA,the stability of pedicle screw can be improved.