Ergur Ipek, Akcali Omer, Kiray Amac, Kosay Can, Tayefi Hamid
Department of Anatomy, School of Medicine, Dokuz Eylul University, Izmir, Turkey.
Eur Spine J. 2007 Sep;16(9):1519-23. doi: 10.1007/s00586-007-0326-x. Epub 2007 Feb 14.
The aim of this cadaver study is to define the anatomic structures on anterior sacrum, which are under the risk of injury during bicortical screw application to the S1 and S2 pedicles. Thirty formaldehyde-preserved human male cadavers were studied. Posterior midline incision was performed, and soft tissues and muscles were dissected from the posterior part of the lumbosacral region. A 6 mm pedicle screw was inserted between the superior facet of S1 and the S1 foramen. The entry point of the S2 pedicle screw was located between S1 and S2 foramina. S1 and S2 screws were placed on both right and the left sides of all cadavers. Then, all cadavers were turned into supine position. All abdominal and pelvic organs were moved away and carefully observed for any injury. The tips of the sacral screws were marked and the relations with the anatomic structures were defined. The position of the sacral screws relative to the middle and lateral sacral arteries and veins, and the sacral sympathetic trunk were measured. There was no injury to the visceral organs. In four cases, S1 screw tip was in direct contact with middle sacral artery. In two cases, S1 screw tip was in direct contact with middle sacral vein. It was observed that the S1 screw tips were in close proximity to sacral sympathetic trunk on both right and the left sides. The tip of the S2 screw was in contact with middle sacral artery on the left side only in one case. It is found that the tip of the S2 screw was closely located with the middle sacral vein in two cases. The tip of the S2 pedicle screw was in contact with the sacral sympathetic trunk in eight cases on the right side and seven cases on the left side. Lateral sacral vein was also observed to be disturbed by the S1 and S2 screws. As a conclusion, anterior cortical penetration during sacral screw insertion carries a risk of neurovascular injury. The risk of sacral sympathetic trunk and minor vascular structures together with the major neurovascular structures and viscera should be kept in mind.
本尸体研究的目的是明确骶骨前部的解剖结构，这些结构在向S1和S2椎弓根置入双皮质螺钉的过程中存在受伤风险。研究了30具用甲醛保存的男性尸体。进行后正中切口，从腰骶部后方解剖软组织和肌肉。在S1上关节突与S1椎间孔之间插入一枚6mm椎弓根螺钉。S2椎弓根螺钉的进针点位于S1和S2椎间孔之间。在所有尸体的左右两侧均置入S1和S2螺钉。然后，将所有尸体转为仰卧位。移开所有腹部和盆腔器官，并仔细观察有无损伤。标记骶骨螺钉的尖端，并明确其与解剖结构的关系。测量骶骨螺钉相对于骶中动静脉和骶交感干的位置。内脏器官未受损伤。在4例中，S1螺钉尖端与骶中动脉直接接触。在2例中，S1螺钉尖端与骶中静脉直接接触。观察到左右两侧的S1螺钉尖端均与骶交感干紧邻。仅在1例中，S2螺钉尖端与左侧的骶中动脉接触。在2例中发现S2螺钉尖端与骶中静脉紧邻。S2椎弓根螺钉尖端在右侧8例和左侧7例中与骶交感干接触。还观察到骶外侧静脉也受到S1和S2螺钉的干扰。结论是，骶骨螺钉置入过程中前皮质穿透存在神经血管损伤风险。应牢记骶交感干和小血管结构以及主要神经血管结构和内脏的风险。
