Linhardt Oliver, Lüring Christian, Matussek Jan, Hamberger Corinna, Plitz Wolfgang, Grifka Joachim
Orthopaedic Department, University Regensburg, Bad Abbach, Germany.
J Spinal Disord Tech. 2006 Apr;19(2):87-91. doi: 10.1097/01.bsd.0000177212.52583.bd.
The goal of this cadaver study was to compare the stability of pedicle screws after implantation in soft or cured kyphoplasty cement.
Pedicle screws were inserted in a total of 30 thoracolumbar vertebrae of 10 different human specimens: 10 screws were implanted in nonaugmented vertebrae (group 1), each 10 screws were placed in soft (group 2) and cured (group 3) cement. Pedicle screws were than evaluated for biomechanical axial pullout resistance.
Mean axial pullout strength was 232 N (range 60-600 N) in group 1, 452 N (range 60-1125 N) in group 2 and 367 N (range 112-840 N) in group 3. The paired Student t-test demonstrated a significant difference between pullout strength of groups 1 and 2 (P = 0.0300). Between pullout strength of groups 1 and 3 and between groups 2 and 3 no significant difference was seen.
We achieved a 1.9 times higher pullout strength with kyphoplasty augmentation of osteoporotic vertebrae compared with the pullout strength of nonaugmented vertebrae. Implantation of pedicle screws in cured cement is a sufficient method. With this method we found a 1.6 times higher pullout strength then in nonaugmented vertebrae.
本尸体研究的目的是比较椎弓根螺钉植入软质或固化椎体后凸成形术骨水泥后的稳定性。
在10个不同人体标本的总共30个胸腰椎椎体中插入椎弓根螺钉：10枚螺钉植入未强化的椎体（第1组），每组10枚螺钉分别置于软质骨水泥（第2组）和固化骨水泥（第3组）中。然后评估椎弓根螺钉的生物力学轴向拔出阻力。
第1组平均轴向拔出强度为232 N（范围60 - 600 N），第2组为452 N（范围60 - 1125 N），第3组为367 N（范围112 - 840 N）。配对t检验显示第1组和第2组的拔出强度之间存在显著差异（P = 0.0300）。第1组和第3组以及第2组和第3组的拔出强度之间未观察到显著差异。
与未强化椎体相比，椎体后凸成形术强化骨质疏松椎体可使拔出强度提高1.9倍。将椎弓根螺钉植入固化骨水泥是一种有效的方法。采用这种方法，我们发现拔出强度比未强化椎体高1.6倍。
