Höch Andreas, Schimpf Richard, Hammer Niels, Schleifenbaum Stefan, Werner Michael, Josten Christoph, Böhme Jörg
.
Biomed Tech (Berl). 2017 Aug 28;62(4):421-428. doi: 10.1515/bmt-2016-0235.
Cement augmentation of pedicle screws is the gold standard for the stabilization of osteoporotic fractures of the spine. In-screw cement augmentation, in which cement is injected through the cannula, is another option for fracture stabilization of fragility fractures of the sacrum. However, biomechanical superiority of this technique compared to conventional sacroiliac screw fixation has not been tested. The present study compares the stability of cement-augmented and non-cement-augmented sacroiliac screw fixation in osteoporotic sacrum fractures under cyclic loading. Eight human donor pelvises with intact ligaments and 5th lumbar vertebra were dissected. A vertical shear fracture was created as a combination of a sacrum fracture and cutting of the symphysis. Both sides were tested in a single-limb-stance setup with 10,000 loading cycles applied. Stiffness of the pelvis and displacement of the fracture were measured using a hydraulic testing machine and a 3D image correlation system. The augmented screw fixation failed in two of eight pelvises, and the non-augmented screws failed in three of eight pelvises. CT scans showed no leakage of cement. In-screw polymethylmethacrylate (PMMA) augmentation showed no advantage based on measured displacement of the sacrum fractures or stiffness for sacroiliac screw fixation of fragility fractures of the sacrum.
椎弓根螺钉骨水泥强化是治疗骨质疏松性脊柱骨折的金标准。通过套管注入骨水泥的螺钉内骨水泥强化是治疗骶骨脆性骨折的另一种骨折稳定方法。然而，与传统骶髂螺钉固定相比，该技术的生物力学优势尚未得到验证。本研究比较了骨质疏松性骶骨骨折在循环载荷下骨水泥强化和非骨水泥强化骶髂螺钉固定的稳定性。解剖了8个韧带完整且包含第5腰椎的人类供体骨盆。通过骶骨骨折和耻骨联合切开相结合的方式制造垂直剪切骨折。两侧均在单腿站立装置中进行测试，施加10000次加载循环。使用液压试验机和三维图像相关系统测量骨盆的刚度和骨折的位移。8个骨盆中有2个骨水泥强化螺钉固定失败，8个骨盆中有3个非骨水泥强化螺钉固定失败。CT扫描显示无骨水泥渗漏。基于测量的骶骨骨折位移或骶骨脆性骨折骶髂螺钉固定的刚度，螺钉内聚甲基丙烯酸甲酯（PMMA）强化未显示出优势。
