兔模型行经皮椎体成形术和经皮椎体后凸成形术术后腰椎生物力学功能改变的实验研究

Research on changes in lumbar biomechanical function of rabbit model after PVP and PKP

目的研究在兔骨质疏松模型中行经皮椎体成形术(PVP)和经皮椎体后凸成形术(PKP)对模型腰椎生物力学功能的影响。方法将新西兰大白兔通过切除双侧卵巢建立骨质疏松模型,造模成功58例,分为两组,A组29只,予以行PVP手术,B组29只,予以行PKP手术,观察两组模型术后椎体弯曲和压缩实验最大载荷量的变化,椎体术后平均高度和矢状面Cobb角的改变。结果两组兔模型行PKP和PVP术后,椎体承载压力能力得到了显著提升,差异较手术前具有显著的统计学意义(P<0.01),B组术后椎体承载压力能力提高较A组明显,其差异具有统计学意义(P<0.05)。但术后6、12和18个月两组模型承载压力能力逐渐下降。术后观察18个月,A组手术椎体术后平均高度和矢状面Cobb角与术前相比,差异无统计学意义(P>0.05),B组模型18个月后手术椎体前缘平均高度由术前(38.81±8.12)%恢复至(80.17±16.38)%,矢状面Cobb角由术前(30.13±8.75)°恢复至(8.69±3.45)°。B组椎体术后高度测量值和Cobb角的变化与A组相比,差异具有统计学差异(P<0.05)。A组6个月后手术部位邻近椎体新发骨折率为20.69%,12个月后为24.14%,18个月后为31.03%;B组6和12个月后均为3.45%,18个月后为6.90%,在新发邻椎骨折方面,PKP优于PVP(P<0.05)。结论 PKP可更好地改善后凸角度,更显著地改善椎体承载压力的能力;减少新发邻近椎体骨折的发生率,但尚需更多设计严谨的随机对照研究加以证实。

[ Objective ] To research the changes in lumbar biomechanical function of rabbit model after percuta- neous vertebroplasty （PVP） and percutaneous kyphoplasty （PKP）. [Methods ] New Zealand rabbits were ovariec- tomized to establish osteoporosis models; successful modeling was obtained in 58 cases, which were divided into two groups, 29 rats in group A underwent PVP operation, 29 rats in group B underwent PKP operation; The changes in maximum load of vertebral bending and compression experiment, and changes in average height and the sagittal Cobb angle of the vertebral body after operation were observed in the two groups. [ Results ] The vertebral pressure bearing ability of two groups of rabbit model after PKP （group B） and PVP （group A） was significantly improved compared with that before operation, the difference was statistically significant （P 〈 0.01）; postoperative vertebral pressure bearing ability of group B improved obviously compared with group A, the difference had statistical signifi- cance （P 〈 0.05）. But after 6 months, 12 months and 18 months, pressure bearing ability in two groups declined.Through an observation of 18 months after operation, the difference in the vertebral average height and sagittal Cobb angle of group A before and after operation had no statistical significance （P 〉 0.05）; eighteen months after the oper- ation, the average anterior vertebral height recovered from preoperative （38.81±8.12）% to （80.17±16.38）% in group B, and sagittal Cobb angle recovered from preoperative （30.13±8.75）° to （8.69±3.45）°. The difference in the vertebral height and Cobb angle measurement value between group A and group B had statistical significance （P 〈 0.05）. The incidence of new adjacent vertebral fractures 6 months after the operation was 20.69%, after 12 months was 24.14%, after 18 months was 31.03% in group A; In group B the incidence was 3.45% after 6 months and 12 months, and 6.90% after 18 months. In the new adjacent vertebral fractures, PKP is better than PVP （P 〈 0.05）. [ Conclusions] PKP can better improve the kyphosis angle and the vertebral pressure bearing ability, reduce the incidence of adja- cent vertebral fractures, but it still need to be confirmed through more rigorously designed randomized studies.