Long-Term Outcomes of Patients with Superior Facet Joint Violation by Pedicle Screws after Minimally Invasive Transforaminal Lumbar Interbody Fusion

Abstract

Purpose: This study aimed to assess the superior facet joint violation (SFJV) rate by percutaneously placed pedicle screws in a series of patients treated with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar degenerative disease. Another purpose of this research was to evaluate the long-term clinical and radiological outcomes in the group of patients with documented SFJV, through a matched comparison with a group without facet joint violation. Methods: This retrospective cohort study enrolled patients with degenerative lumbar spine disease who underwent MIS-TLIF, with at least 5-year follow-up. 1-year postoperative CT scans were used to identify facet joint violations. Two-to-one propensity score matching was performed for patients without and with SFJV, respectively. Clinical outcomes used ODI, back and leg NRS and EQ-5D. Radiological evaluation was performed preoperatively, 1 year and averaging 8 years after surgery, including: superior adjacent segment (SAS) disc height, angle and range of motion, lumbar lordosis, pelvic tilt, pelvic incidence, and sagittal vertical axis. Results: This study included 196 patients with a median follow-up after surgery of 113 months. Twenty-two patients were found to have SFJV, corresponding to 11.2% of the patients and to 7.1% of top-level screws. Factors associated with SFJV were SAS angle (OR=0.8; p=0.001 for SAS angle) and a trend to L5-S1 fusion (OR=5.3, p=0.052). Sixty-six patients were sampled with propensity score matching. The patients in the 2 groups did not differ in clinical and radiological outcomes 8 years after the surgery. Conclusion: We found SFJV in 11.2% of the patients submitted to MIS-TLIF with percutaneous pedicle screws for degenerative lumbar disease. In a matched sample, SFJV following MIS-TLIF had no impact in the long-term follow-up regarding clinical results or SAS degeneration.