C1 Posterior Arch Crossing Screw Fixation for Atlantoaxial Joint Instability

作者：Guoxin Jin, Huan Wang, Lei Li, Shaoqian Cui, Jingzhu Duan · 发表于：Spine · 年份：2013 · DOI：10.1097/brs.0b013e3182a40869 · 被引用次数：24 · 研究领域：Spinal Fractures and Fixation Techniques、Cervical and Thoracic Myelopathy、Spinal Hematomas and Complications

STUDY DESIGN: Anatomical measurements and in vitro biomechanical testing were performed to evaluate a new method for posterior C1 fixation. OBJECTIVE: This study sought to assess C1 posterior arch crossing screw fixation for posterior C1-C2 fixation, using anatomical measurements and biomechanical testing with traditional C1 pedicle screws (PS) in a cadaveric model. SUMMARY OF BACKGROUND DATA: Atlantoaxial instability often requires surgery, and the current methods for atlas fixation incur some risk to the vascular and neurological tissues. Thus, new, effective, and safe methods are needed for salvage operations. METHODS: Morphometric analysis of the C1 posterior arch was performed using 3-dimensional computed tomography. Six fresh ligamentous human cervical spines (C0-C4) were evaluated for their biomechanics. The specimens were tested in their intact condition and after stabilization (C1-C2 PS, C1 posterior arch screws [PAS] with C2 PS) and injury due to 1.5 N·m of pure moment in flexion, extension, lateral bending, and axial rotation. During testing, 3-dimensional angular motion was measured with a motion capture platform (Vicon Nexus). Data for all scenarios were recorded, and statistical analysis was performed. RESULTS: Anatomical assessment indicated that 91.51% of C1 posterior tubercles exceeded 7 mm in thickness, 93.40% had a width of the posterior arch of greater than 3.5 mm, and 65.57% had a unilateral screw length of greater than 15 mm, indicating that the posterio...