Pedicle Screw-Associated Violation of the Adjacent Unfused Facet Joint: Clinical Outcomes and Fusion Rates

Nathan J. Sinz, Raymond W. Hwang, Gyu Ho Lee, Kevin C. Baker, Paul Arnold, Rick Sasso, Daniel Park, Jeffrey Fischgrund, Ruijia Niu, David H. Kim

Research output: Contribution to journalArticlepeer-review


Study Design: Retrospective review of a prospective randomized trial. Objectives: To compare outcome scores and fusion rates in patients with and without pedicle screw-associated facet joint violation (FJV) after a single-level lumbar fusion. Methods: Clinical outcomes data and computed tomography (CT) imaging were reviewed for 157 patients participating in a multicenter prospective trial. Post-operative CT scans at 12-months follow-up were examined for fusion status and FJV. Patient-reported outcomes (PROs) included Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for leg and low back pain. Chi-square test of independence was used to compare proportions between groups on categorical measures. Two-sample t-test was used to identify differences in mean patient outcome scores. Logistic regression models were performed to determine association between FJV and fusion rates. Results: Of the 157 patients included, there were 18 (11.5%) with FJV (Group A) and 139 (88.5%) without FJV (Group B). Patients with FJV experienced less improvement in ODI (P =.004) and VAS back pain scores (P =.04) vs patients without FJV. There was no difference in mean VAS leg pain (P =.4997). The rate of fusion at 12-months for patients with FJV (27.8%) was lower compared to those without FJV (71.2%) (P =.0002). Patients with FJV were 76% less likely to have a successful fusion at 12-months. Conclusion: Pedicle screw-associated violation of the adjacent unfused facet joint during single-level lumbar fusion is associated with less improvement in back pain, back pain-associated disability, and a lower fusion rate at 1-year after surgery.

Original languageEnglish (US)
Pages (from-to)1477-1484
Number of pages8
JournalGlobal Spine Journal
Issue number5
StatePublished - Jun 2024


  • adjacent level disease
  • facet joint
  • facet joint impingement
  • facet joint violation
  • instrumented fusion
  • interbody fusion
  • lumbar fusion
  • lumbar laminectomy
  • outcome scores
  • outcomes
  • pedicle screws
  • transforaminal lumbar interbody fusion

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery
  • Orthopedics and Sports Medicine


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