Nucci R C, Seigal S, Merola A A, Gorup J, Mroczek K J, Dryer J, Zipnick R I, Haher T R
Department of Orthopaedic Surgery, S.U.N.Y. Downstate Medical Center, Brooklyn, USA.
Spine (Phila Pa 1976). 1995 Feb 1;20(3):264-70. doi: 10.1097/00007632-199502000-00002.
Computed tomography scans of the dens were performed on patients who had no atlantoaxial pathology.
To determine whether one or two screws is optimal for fracture fixation and whether two screws can always negotiate the intramedullary odontoid cavity.
Fixation of Type II dens fractures traditionally has used C1-C2 posterior wiring and fusion. Two screws placed across an odontoid fracture as a method of rigid internal fixation also has been described. However, it is not known whether two screws can always negotiate the odontoid canal.
Ninety-two consecutive computerized tomography scans of the dens were performed on adults who had no atlantoaxial pathology. Measurements were taken from the scan and compared with the cross-sectional diameter of two odontoid screws.
The critical diameter for the placement of two 3.5-mm cortical screws with tapping was 9.0 mm. This dimension was present in 95% of the patients studied.
Correct orientation of the computerized tomography scanner is critical for accurate measurements. Two 3.5-mm screws can be used in internal fixation of Type II dens fractures in 95% of the patients if the inner cortex is tapped.
对无寰枢椎病变的患者进行齿状突的计算机断层扫描。
确定单枚或双枚螺钉用于骨折固定是否最佳，以及双枚螺钉是否总能通过齿状突髓腔。
传统上，II型齿状突骨折的固定采用C1-C2后路钢丝固定和融合术。也有描述将两枚螺钉穿过齿状突骨折作为一种坚强内固定方法。然而，尚不清楚双枚螺钉是否总能通过齿状突管。
对92例无寰枢椎病变的成年人进行连续的齿状突计算机断层扫描。从扫描图像上进行测量，并与两枚齿状突螺钉的横截面直径进行比较。
置入两枚带攻丝的3.5毫米皮质骨螺钉的临界直径为9.0毫米。在所研究的患者中，95%的患者存在该尺寸。
计算机断层扫描仪的正确定位对于准确测量至关重要。如果对内侧皮质进行攻丝，95%的患者的II型齿状突骨折内固定可使用两枚3.5毫米螺钉。
