Several surgical techniques have been described for stabilization of the atlantoaxial complex. Each technique differs in its biomechanical properties, advantages and disadvantages. In this series, we describe our experience with a combined four-point fixation technique that combines C1-C2 transarticular with C1 lateral mass fixation for atlanto-axial instability.
We present a single center retrospective case series of thirty patients who were surgically treated for atlantoaxial instability over one decade. All patients presented with symptoms and signs of atlanto-axial instability and consequently underwent extensive clinical and radiological evaluation prior to surgery.
The median follow-up of our cohort was…show more content… The pre-operative and postoperative Ranawat scores were available for 26 out of 30 patients. Ranawat scores improved following surgery in 8/26 (30.7%) patients, did not change in 17 (65.4%) patients, and worsened in only one patient (3.8%). Like the VAS score, improvement in Ranawat score following surgery was significant (p=0.02) in paired analysis. All patients’ post-operative imaging confirming stability of the construct.
Complications in this series included two unilateral intraoperative vertebral artery injuries associated with placement of C1-C2 transarticular screws, another patient had worsening C2 pain following surgery, and three patients had numbness in the C2 distribution following the procedure. Radiologically, two patients had suboptimal unilateral C2 screw placement despite satisfactory intraoperative fluoroscopic imaging (Figure 4). In both patients the construct was stable in dynamic views as the proximal portion of the transarticular screw functioned as a C2 pars interarticularis screw (figure X). There were no post-operative infections (Table1).
Complication Type Presentation Remedy Impact
3 cases of C2 distribution numbness Clinical - post op Numbness Conservative Transient
2 cases of inability to place a C1-C2 transarticular screw Intraoperative Technical difficulty due to cortex breach C1 lateral mass to C2 lateral mass construct No