Terai T, Sairyo K, Goel V K, Ebraheim N, Biyani A, Faizan A, Sakai T, Yasui N
Department of Orthopaedics, University of Tokushima, School of Medicine, 3-18-15, Kuramoto, Tokushima 770-8503, Japan.
J Bone Joint Surg Br. 2010 Aug;92(8):1123-7. doi: 10.1302/0301-620X.92B8.22883.
Lumbar spondylolysis is a stress fracture of the pars interarticularis. We have evaluated the site of origin of the fracture clinically and biomechanically. Ten adolescents with incomplete stress fractures of the pars (four bilateral) were included in our study. There were seven boys and three girls aged between 11 and 17 years. The site of the fracture was confirmed by axial and sagittal reconstructed CT. The maximum principal tensile stresses and their locations in the L5 pars during lumbar movement were calculated using a three-dimensional finite-element model of the L3-S1 segment. In all ten patients the fracture line was seen only at the caudal-ventral aspect of the pars and did not spread completely to the craniodorsal aspect. According to the finite-element analysis, the higher stresses were found at the caudal-ventral aspect in all loading modes. In extension, the stress was twofold higher in the ventral than in the dorsal aspect. Our radiological and biomechanical results were in agreement with our clinical observations.
腰椎峡部裂是关节突间部的应力性骨折。我们从临床和生物力学方面评估了骨折的起源部位。本研究纳入了10例关节突不完全应力性骨折的青少年（4例双侧骨折）。其中有7名男孩和3名女孩，年龄在11至17岁之间。骨折部位通过轴向和矢状面重建CT得以确认。利用L3 - S1节段的三维有限元模型计算了腰椎运动过程中L5关节突的最大主拉应力及其位置。在所有10例患者中，骨折线仅见于关节突的尾侧腹侧，未完全延伸至头侧背侧。根据有限元分析，在所有加载模式下，尾侧腹侧的应力更高。在伸展时，腹侧应力比背侧高出两倍。我们的放射学和生物力学结果与临床观察结果一致。
