Kretzer Ryan M, Sciubba Daniel M, Bagley Carlos A, Wolinsky Jean-Paul, Gokaslan Ziya L, Garonzik Ira M
Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
J Neurosurg Spine. 2006 Dec;5(6):527-33. doi: 10.3171/spi.2006.5.6.527.
The use of pedicle screws (PSs) for instrument-assisted fusion in the cervical and thoracic spine has increased in recent years, allowing smaller constructs with improved biomechanical stability and repositioning possibilities. In the smaller pedicles of the upper thoracic spine, the placement of PSs can be challenging and may increase the risk of damage to neural structures. As an alternative to PSs, translaminar screws can provide spinal stability, and they may be used when pedicular anatomy precludes successful placement of PSs. The authors describe the technique of translaminar screw placement in the T-1 and T-2 vertebrae.
Seven patients underwent cervicothoracic fusion to treat trauma, neoplasm, or degenerative disease. Nineteen translaminar screws were placed, 13 at T-1 and six at T-2. A single asymptomatic T-2 screw violated the ventral laminar cortex and was removed. The mean clinical and radiographic follow up exceeded 14 months, at which time there were no cases of screw pullout, screw fracture, or progressive kyphotic deformity.
Rigid fixation with translaminar screws offers an attractive alternative to PS fixation, allowing the creation of sound spinal constructs and minimizing potential neurological morbidity. Their use requires intact posterior elements, and care should be taken to avoid violation of the ventral laminar wall.
近年来,椎弓根螺钉(PSs)在颈椎和胸椎器械辅助融合中的应用有所增加,使得植入物更小,生物力学稳定性提高且具备重新定位的可能性。在上胸椎较小的椎弓根中,椎弓根螺钉的置入可能具有挑战性,并且可能增加神经结构损伤的风险。作为椎弓根螺钉的替代方法,经椎板螺钉可提供脊柱稳定性,当椎弓根解剖结构妨碍椎弓根螺钉成功置入时可使用。作者描述了在T1和T2椎体置入经椎板螺钉的技术。
7例患者接受了颈胸段融合术以治疗创伤、肿瘤或退行性疾病。共置入19枚经椎板螺钉,其中13枚位于T1,6枚位于T2。1枚无症状的T2螺钉穿透了腹侧椎板皮质,予以取出。临床和影像学随访平均超过14个月,此时没有螺钉拔出、螺钉断裂或进行性后凸畸形的病例。
经椎板螺钉的坚强固定为椎弓根螺钉固定提供了一种有吸引力的替代方法,能够构建稳固的脊柱植入物并将潜在的神经并发症降至最低。其应用需要完整的后部结构,并且应注意避免穿透腹侧椎板壁。