Proximal facet joint violation and breaches after percutaneous insertion of 311 lumbar pedicle screws using the pedicle axis fluoroscopic view.

INTRODUCTION

Violation of the non-fused proximal facet joints (PFJ) above instrumentation might be associated with accelerated arthritis and adjacent-segment disease. Standard fluoroscopic views do not allow for an exclusion of PFJ violation and have been associated with high rates of this complication.

RESEARCH QUESTION

We adopted the use of the pedicle axis view (PAV) and investigated our results and potential correlations.

MATERIALS AND METHODS

We performed a retrospective cohort study of cases of percutaneous pedicle screw insertion in the lumbar spine, using the PAV. Various factors were investigated on postoperative CT scans, e.g. presence of PFJ violation, PFJ angles and analysis of breaches.

RESULTS

Overall, 311 screws were inserted using the PAV. The percentage of screws that resulted in PFJ violation was 3.7 % (n = 6). Higher PFJ angles played a role with an odds ratio of 1.21 (95 % CI: 1.03-1.43). The majority of the screws (68.1 %) did not cause cortical breaches. Regarding the rates of breaches, 14.9 % were minor cortical breaches and 11.6 % were moderate. 1.9 % of the screws caused severe breaches, but none of those were located medially or inferiorly. None of the observed breaches led to new symptoms or revision.

DISCUSSION AND CONCLUSION

The adoption of the fluoroscopic PAV for percutaneous lumbar pedicle screws led to low rates of proximal facet joint violation and severe breaches. Moreover, PFJ violation was more prevalent with higher PFJ angles and surgeons should remain vigilant in such cases. None of the observed breaches were clinically relevant.