A comparison of open versus percutaneous cervical transfacet fixation

OBJECTIVE The aim of this study is to describe a technique for percutaneous cervical transfacet screw placement and compare this technique to the open technique with regard to the accuracy of facet capture and the potential of placing neurovascular structures at risk. METHODS Eight cadaveric cervical spines were harvested. One side of each spine was assigned to the percutaneous group, and the other side to the open group. The spines were instrumented from C-3 to T-1 (80 screws). The distance to the spinal canal, foramen transversarium, and neural foramen were measured to determine the likelihood of placing neurovascular structures at risk. The percentage of the facet joint captured and the angle of screw trajectory compared with the ideal trajectory were used to determine the accuracy. RESULTS There were, in total, 11 misplacements of screws: 2 screws using the open technique and 9 screws using the percutaneous technique (p = 0.006). From a neurovascular point of view, 3 percutaneous screws violated the foramen transversarium. Two of these percutaneous screws violated the neural foramen. No neurovascular foramina were violated using the open technique. The open technique resulted in a significantly greater distance from the screw to the spinal canal (p < 0.001). The distance from the screw to the foramen transversarium (p = 0.015), as well as the distance from the screw to the neural foramen (p = 0.012), did not demonstrate statistical difference when using either technique. As for the accuracy of facet capture, 8 screws exhibited less than 15% purchase of the facet joint. Six of these screws were placed using the percutaneous technique, and 2 screws were placed using the open technique. CONCLUSIONS There is a higher incidence of screw misplacement using the percutaneous transfacet in comparison to the open transfacet technique. The accuracies of facet capture using the 2 techniques were not statistically different. Surgeons will need to understand the potential risk of using the percutaneous technique as an alternative to open transfacet fixation.