选择性骶骨切除对骨盆生物力学稳定性的影响

目的用生物力学测试的方法分析新鲜人骨盆模型不同骶骨平面切除对骨盆稳定性的影响。方法选用8具男性新鲜尸体L5-骨盆标本,平稳加载至1 000 N,对各个测试点保留完整骶骨及不同平面骶骨切除骨盆模型的剪切应力、最大主应力、位移及刚度变化依次测试,并比较各组间的差异。进行骨盆环的测量,记录骨折部位和骨折类型。结果随着骶骨切除平面的增高,各个测试点的剪切应力、最大主应力及骶骨下沉位移均有不同程度增大,骨盆的轴向刚度逐渐减小。当切除平面到达S_1时变化明显,尤以经过1/4 S_1组、1/2S_1组变化显著,与S_0组比较差异均有统计学意义(P0.05)。结论骶骨的切除范围与骨盆的生物力学稳定性密切相关,残留骶髂关节各种应力随着骶骨切除平面升高而急剧增高,骨盆的稳定性明显下降。当骶骨切除到S_1椎体时,极易发生骨折,需要通过腰骶髂局部重建的方式增强骶髂关节的稳定性。

Effect on pelvic biomechanical stability of selective sacrectomy

Objective To analyse the relationship between different sacral resection plane and the pelvic stability with the method of biomechanics test in fresh human pelvis model. Methods 8 samples of male fresh cadaveric L5-pelvic specimens were selected, steady shear loaded to 1 000 N, complete sacral and different plane sacrectomy pelvic mod-el stress, the maximum principal stress, displacement and stiffness variation of each testing point was tested in turn retained, and the differences between each group were compared. Pelvic ring measurements were performed to record the fracture site and type of fracture. Results With the increase of shear plane sacral resection, each testing point should be the maximum principal stress, the stress and displacement of the sacrum sinking had different degrees of in-creasing, and pelvic axial stiffness decreases. Especially when the resection plane arrived at the sacral 1, change was obvious, especially after the 1/4 S1 group, 1/2 S1 group changed significantly, compared with the S0 group, the difference was statistically significant (P<0. 05). Conclusions The biomechanical stability of pelvic sacral resec-tion range is closely related to the sacroiliac joint, residual stress with various sacrectomy levels and increases dramat-ically, pelvic stability decreases significantly. When the sacral resection to 1 sacral vertebral, it is extremely easy to fracture, which need to strengthen the stability of the sacroiliac joint through the waist sacroiliac local reconstruction methods.