Ulibarri James A, Anderson Paul A, Escarcega Tony, Mann David, Noonan Kenneth J
Department of Orthopaedics and Rehabilitation, University of Wisconsin, Madison, WI 53792, USA.
Spine (Phila Pa 1976). 2006 Aug 15;31(18):2067-72. doi: 10.1097/01.brs.0000231777.24270.2b.
A biomechanical comparison of a novel spondylolysis repair technique method to established spondylolysis repair constructs accompanied by a case series of 5 adolescent patients with spondylolysis treated with this technique.
To provide retrospective data on these patients treated with an intralaminar link construct, as well as present comparative biomechanical data on this construct and that of an intact spine, lytic spine, and known methods of repair.
Spondylolysis is a unilateral or bilateral defect in the pars interarticularis, and most commonly occurs at L5 and less frequently at L4. Surgical treatment may be indicated in patients with persistent pain and impairment despite conservative treatment. Unlike posterolateral fusion, direct pars repairs may benefit adolescents by sparing motion segments.
Biomechanical testing of 5 cadaver lumbar spines was completed to provide comparative biomechanical data on this intralaminar link construct, and that of an intact spine, destabilized spondylolytic spine, Scott wiring technique, pedicle screw-cable system, and the pedicle screw-rod-hook constructs. There were 5 adolescent patients with spondylolysis treated with multiaxial pedicle screws, with a modular linkage that passes beneath the spinous process of the same segment.
Biomechanical evaluation of the intralaminar link construct showed the least displacement (across pars defect) followed by the pedicle screw-rod-hook system, Scott wiring, and, finally, the pedicle screw-cable system. Interbody flexion and extension stiffness was highest for pedicle screw-rod-hook followed by normal, intralaminar link construct, Scott wiring, pedicle screw-cable system, and, finally, the destabilized spine. Interbody torsional stiffness was highest for pedicle screw-rod-hook followed by intralaminar link construct, normal, pedicle screw-cable system, Scott wiring, and lytic spine. Retrospective follow-up (average 4.6 years) of patients showed complete radiographic healing or pain relief in all 5 patients. There was 1 patient with solid healing of L3 spondylolysis who later had onset pain despite evidence of solid fusion on computerized tomographic images. In this patient, pain resolved after implant removal.
Biomechanical evaluation of the intralaminar link construct showed excellent stability of a spondylolytic defect in comparison to established methods. Clinical follow-up of this method reflects the results of biomechanical testing with excellent clinical results.
对一种新型椎弓峡部裂修复技术方法与既定的椎弓峡部裂修复结构进行生物力学比较，并伴有5例采用该技术治疗的青少年椎弓峡部裂患者的病例系列。
提供这些采用椎板内连接结构治疗的患者的回顾性数据，并给出该结构与完整脊柱、椎弓峡部裂脊柱以及已知修复方法的比较生物力学数据。
椎弓峡部裂是关节突间部的单侧或双侧缺损，最常见于L5，较少见于L4。尽管进行了保守治疗，但持续疼痛和功能障碍的患者可能需要手术治疗。与后外侧融合不同，直接修复椎弓峡部可能对青少年有益，因为可以保留运动节段。
对5具尸体腰椎进行生物力学测试，以提供该椎板内连接结构与完整脊柱、不稳定的椎弓峡部裂脊柱、斯科特钢丝固定技术、椎弓根螺钉 - 缆索系统以及椎弓根螺钉 - 棒 - 钩结构的比较生物力学数据。有5例青少年椎弓峡部裂患者采用多轴椎弓根螺钉治疗，其模块化连接在同一节段棘突下方穿过。
椎板内连接结构的生物力学评估显示（跨椎弓峡部缺损处）位移最小，其次是椎弓根螺钉 - 棒 - 钩系统、斯科特钢丝固定，最后是椎弓根螺钉 - 缆索系统。椎弓根螺钉 - 棒 - 钩的椎间屈伸刚度最高，其次是正常脊柱、椎板内连接结构、斯科特钢丝固定、椎弓根螺钉 - 缆索系统，最后是不稳定脊柱。椎间扭转刚度最高的是椎弓根螺钉 - 棒 - 钩，其次是椎板内连接结构、正常脊柱、椎弓根螺钉 - 缆索系统、斯科特钢丝固定以及椎弓峡部裂脊柱。对患者的回顾性随访（平均4.6年）显示，所有5例患者均实现了影像学完全愈合或疼痛缓解。有1例L3椎弓峡部裂患者实现了牢固愈合，但尽管计算机断层扫描图像显示融合牢固，后来仍出现疼痛。在该患者中，取出植入物后疼痛缓解。
与既定方法相比，椎板内连接结构的生物力学评估显示椎弓峡部裂缺损具有出色的稳定性。该方法的临床随访反映了生物力学测试的结果，临床效果极佳。
