ABSTRACT
A vertebral artery (VA) injury presents a difficult problem in atlantoaxial fixation. Recent technical reports described posterior C2 fixation using bilateral, crossing C2 laminar screws. The translaminar screw technique has the advantages of producing little risk of VA injury and the unconstrained screw placement. In addition, biomechanical studies have demonstrated the potential of the translaminar screw technique to provide a firmer construct that is equivalent to methods currently used. We report the successful treatment of C1-2 instability with a left-side high-riding VA. Because of the potential risk of VA injury, we performed a posterior C1-2 fixation with a combination of pedicle screws and a laminar screw in C2. We first placed bilateral C1 lateral mass screws and a right-side C2 pedicle screw. However, placement of the left- side C2 pedicle screw was technically difficult due to a narrow isthmus and pedicle. A laminar screw was inserted instead and authors believe that this posterior C1-C2 fixation with a combination of pedicle screws and a laminar screw in C2 can be a useful alternative technique for the treatment of C1-C2 instability in the presence of a unilateral high-riding VA.
Subject(s)
Axis, Cervical Vertebra , Vertebral ArteryABSTRACT
To the best of our knowledge, there has been no domestic report on posterior atlantoaxial fusion with segmental screw fixation using C2 laminar screws and C1 lateral mass screws for atlantoaxial subluxation. We report the result of this operation performed in a patient with old atlantoaxial rotary subluxation who required posterior fusion. We chose this technique in this patient because wire fixation was not suitable due to osteoporosis, and transarticular screw fixation and use of C2 pedicle screws were not feasible due to the peculiar bony anatomy of the axis.