C2 Anatomy for Translaminar Screw Placement Based on Computerized Tomographic Measurements

다국어 초록 (Multilingual Abstract)

Study Design: Anatomical study.
Purpose: To evaluate the anatomy of the C2 lamina for translaminar screw placement based on computerized tomographic measurements.
Overview of Literature: C2 translaminar screw insertion is a novel technique for atlanto-axial fixation. The risk of vertebral artery injury can be decreased by this technique. However, a large series of anatomical studies on C2 anatomy in Asian populations is still lacking.
Methods: Two hundred adult C2 vertebrae were evaluated by computerized tomographic imaging. The measured parameters included inner and outer transverse diameters of C2 lamina, C2 laminar length and spino-laminar angle. C2 vertebrae with lamina screw placement feasibility were defined as those with inner transverse diameter larger than 3.5 mm.
Results: The mean inner transverse diameter of the C2 lamina was 4.23±1.22 mm. It was significantly larger in males than in females (4.44±1.29 mm vs. 3.96±1.06 mm, p =0.005). The mean outer transverse diameter of C2 lamina was 6.64±1.36 mm. The mean C2 laminar length was 37.26±4.42 mm. The mean C2 spino-laminar angle was 56.42±6.42 degrees. Seventy-nine percents of patients had inner transverse diameter larger than 3.5 mm.
Conclusions: C2 translaminar screw fixation was feasible in the majority of the adult population. However, there were some people who had small C2 lamina. We recommend preoperative computed tomography evaluation to confirm the feasibility of screw placement.

참고문헌 (Reference)

1 Wright NM, "Vertebral artery injury in C1-2 transarticular screw fixation: results of a survey of the AANS/CNS section on disorders of the spine and peripheral nerves. American Association of Neurological Surgeons/Congress of Neurological Surgeons" 88 : 634-640, 1998

2 Neo M, "Vertebral artery injury during cervical spine surgery: a survey of more than 5600 operations" 33 : 779-785, 2008

3 Yusof MI, "Translaminar screw fixation of the cervical spine in Asian population: feasibility and safety consideration based on computerized tomographic measurements" 34 : 203-207, 2012

4 Meng XZ, "The options of C2 fixation for os odontoideum: a radiographic study for the C2 pedicle and lamina anatomy" 20 : 1921-1927, 2011

5 Bhatnagar R, "The anatomic suitability of the C2 vertebra for intralaminar and pedicular fixation: a computed tomography study" 10 : 896-899, 2010

6 Lau SW, "Study of the anatomical variations of vertebral artery in C2 vertebra with magnetic resonance imaging and its application in the C1-C2 transarticular screw fixation" 35 : 1136-1143, 2010

7 Dorward IG, "Seven years of experience with C2 translaminar screw fixation: clinical series and review of the literature" 68 : 1491-1499, 2011

8 Lehman RA Jr, "Salvage of C2 pedicle and pars screws using the intralaminar technique: a biomechanical analysis" 33 : 960-965, 2008

9 Matsubara T, "Safe atlantoaxial fixation using a laminar screw (intralaminar screw) in a patient with unilateral occlusion of vertebral artery: case report" 32 : E30-E33, 2007

10 Madawi AA, "Radiological and anatomical evaluation of the atlantoaxial transarticular screw fixation technique" 86 : 961-968, 1997

11 Wright NM, "Posterior C2 fixation using bilateral, crossing C2 laminar screws: case series and technical note" 17 : 158-162, 2004

12 Dean CL, "Correlation between computed tomography measurements and direct anatomic measurements of the axis for consideration of C2 laminar screw placement" 9 : 258-262, 2009

13 Gorek J, "Constructs incorporating intralaminar C2 screws provide rigid stability for atlantoaxial fixation" 30 : 1513-1518, 2005

14 Wo-Tack Rhee, "Computerized Tomographic Measurements of Morphometric Parameters of the C2 for the Feasibility of Laminar Screw Fixation in Korean Population" 대한신경외과학회 44 (44): 15-18, 2008

15 Ma XY, "C2 anatomy and dimensions relative to translaminar screw placement in an Asian population" 35 : 704-708, 2010

16 Lapsiwala SB, "Biomechanical comparison of four C1 to C2 rigid fixative techniques: anterior transarticular, posterior transarticular, C1 to C2 pedicle, and C1 to C2 intralaminar screws" 58 : 516-521, 2006

17 Gluf WM, "Atlantoaxial transarticular screw fixation: a review of surgical indications, fusion rate, complications, and lessons learned in 191 adult patients" 2 : 155-163, 2005

18 Nakanishi K, "Application of laminar screws to posterior fusion of cervical spine: measurement of the cervical vertebral arch diameter with a navigation system" 33 : 620-623, 2008

19 Cassinelli EH, "Anatomic considerations for the placement of C2 laminar screws" 31 : 2767-2771, 2006