Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Department of Neurosurgery, Inje University Ilsan Paik Hospital, Neuroscience & Radiosurgery Hybrid Research Center, College of Medicine, Gyeonggi, South Korea.
Oper Neurosurg (Hagerstown). 2021 Mar 15;20(4):E298-E299. doi: 10.1093/ons/opaa397.
We previously introduced C1 pedicle screw placement to treat C1-2 pathology in a patient with normal vertebral artery anatomy.1 However, we should prepare to meet various anatomic variations. Ponticulus posticus is a bony prominence arising from the posterior arch or the superior articulating process of the atlas that completely or partially encircles the vertebral artery.2 We herein report a 79-yr-old female who presented with myelopathy and was diagnosed with compressive myelopathy at the C1 level in magnetic resonance imaging. A computed tomography showed ponticulus posticus (complete type to the right side) with duplication of vertebral artery. She underwent surgical treatment of C1-2 pedicle screw placement and reduction of C1 vertebra under a microscopic view. After C1 laminectomy, both-side vertebral arteries were dissected with a microscissor. The mobilization of upper divisions of vertebral artery was identified to secure the entry point and pedicle to insert a C1 pedicle screw. After complete protection of the upper and lower divisions of vertebral artery and identification of pedicle, a C1 pedicle screw was inserted by a freehand technique. We inserted autologous bone chips in the distracted C1-2 facet joint for facet joint fusion, and the C1 vertebra was pulled out by a rod reducer. After surgery, the patient's symptoms disappeared, and no vertebral artery injury was identified in postoperative 3-dimensional computed tomography angiography. Patient consent was obtained prior to performing the procedure.
我们之前介绍过 C1 椎弓根螺钉置钉技术，用于治疗正常椎动脉解剖结构的 C1-2 病变。1 然而，我们应该准备好应对各种解剖变异。桥弓后突是从寰椎后弓或上关节突发出的骨性突起，完全或部分环绕椎动脉。2 我们在此报告一例 79 岁女性，因脊髓病就诊，磁共振成像诊断为 C1 水平的压迫性脊髓病。CT 显示桥弓后突（右侧完全型）和椎动脉重复。3 患者接受了 C1-2 椎弓根螺钉置入和显微镜下 C1 椎体复位的手术治疗。行 C1 椎板切除术后，用显微剪解剖双侧椎动脉。通过识别椎动脉上部分的活动度，确定进钉点和椎弓根以置入 C1 椎弓根螺钉。在完全保护椎动脉上下部分并识别椎弓根后，采用徒手技术置入 C1 椎弓根螺钉。我们在撑开的 C1-2 关节突间植入自体骨屑，通过杆式减压器将 C1 椎体拉出。4 术后患者症状消失，术后三维 CT 血管造影未见椎动脉损伤。5 手术前获得了患者的同意。
