先天性颈椎2-3融合的形态特点与内固定技术解剖适用性

目的 研究先天性颈椎2-3(C2-3)融合的形态特点,为外科内固定技术的解剖学适用性提供依据.方法 17例先天性C2-3融合连续病例,经螺旋CT扫描后,三维重建C2-3结构,分析其形态特点,测量C2关节间部和C3椎弓根大小,评估螺钉置入的可行性.结果 典型的先天性C2-3融合的典型特征为椎体、椎板、棘突、关节突完全融合,而横突和椎弓根未融合;不完全的椎体、椎板、棘突和关节突融合可见于少数病例.本组17例,不适合3.5 mm螺钉置入者分别见于1例两侧C2关节间部狭窄;3例两侧C3椎弓根狭窄;4例一侧C2关切节间部狭窄;7例一侧C3椎弓根狭窄.结论 尽管先天性C2-3融合解剖形态与正常C2-3结构相异甚大,多数病例应用螺钉内固定技术仍然是可行的.

Morphologic Characteristics of Congenital C2-3 Fusion and Anatomic Applicability to Internal Fixation

Objective To describe the morphologic characteristics of congential C2-3 fusion in order to provide anatomic basis for internal fixation. Methods The anatomic variability of bony structure of C2-3 was assessed via three-dimensional reconstruction after spiral CT scan in 17 patients with congintal C2-3 fusion. The parameters of C2 pars interarticularis and C3 pedicle was measured under MPR (Multi-Planar Reformatting) or MIP (Maximum Intensity Projection) reconstruction. Results A typical congenital C2-3 fusion was characterized by complete bony fusion among vertebral bodies, laminae, spinous processes and articular processes, and unattached transverse processes and pedicles. In the minority of the cases, incomplete fusion of vertebral bodies, laminae, spinous processes and articular processes can be found in a discrete manner. Narrowing of bilateral C2 pars interaticularis and C3 pedicle was seen respectively in 1 and 3 cases. The narrowing of unilateral of C2 pars interticularis and C3 pedicle was seen respectively in 4 and 7 cases. The above-mentioned narrowing caused unsuitability for a 3.5 mm screw placement. Conclusion Although quite a few morphological abnormalities are seen in congenital C2-3 fusion, application of screw fixation techniques in this structure is still feasible in majority of the cases.