Fusion and Patient-reported Outcomes after Navigation-guided Decorticated vs. Non-Decorticated Arthrodesis in Minimally Invasive Sacroiliac Joint Fusion: A Longitudinal Comparative Cohort Study
Neurosurgery Resident Ascension Providence Michigan State University Royal Oak, MI, US
Disclosure(s):
Roxana Beladi, D.O.: No financial relationships to disclose
Introduction: Sacroiliac joint (SIJ) dysfunction is a significant cause of back pain. Despite recent advances in minimally invasive (MIS) SIJ fusion (SIJF), the impact of decortication on fusion rate remains inconclusive. We sought to demonstrate that navigation-guided decorticated direct arthrodesis vs. non-decorticated arthrodesis in MIS SIJF would result in higher fusion rates and satisfactory patient-reported outcomes (PROs).
Methods: We retrospectively reviewed consecutive patients who underwent MIS SIJF with or without decortication from 2016-2022. We included patients who failed more than 6 months of conservative treatment, were diagnosed with a standardized diagnostic regimen, and underwent a postop CT with at least 1-year follow-up. SIJF was performed using either cylindrical threaded implants (CTIs) with SIJ decortication using the O-arm surgical imaging system/stealth station or Triangular Titanium implants (TTI) without decortication using fluoroscopy. The primary outcome was fusion rate evaluated with computed tomography (CT) completed at least twelve months postoperatively. Secondary outcomes included revision surgery, time to revision surgery, Numeric Rating Scale Back (NRS), and Oswestry Disability Index (ODI) measured preoperatively and postoperatively at six and twelve months postoperatively. We also collected patient demographics and perioperative data. We compared the groups using univariate analysis. Multivariable analyses were done to adjust for confounders.
Results: Two hundred and three consecutive patients were included. One hundred and twelve underwent decortication (55%), and ninety-one did not have decortication (45%). The groups were significantly different regarding race and smoking status. Decorticated CTIs were associated with a significantly higher rate of fusion (94.6% vs. 81.3%, p=.003). Both decorticated CTIs (Δ 6.49, 95% CI 3.22 - 12.64, p<.001) and non-decorticated TTIs(Δ 6.31, 95% CI 1.73-10.89, p<.001) demonstrated significantly improved ODI at six months postop compared to baseline. However, only decorticated CTIs demonstrated significant improvement in ODI at twelve months and NRS-back at six months postoperatively. Adjusted for smoking and race, multivariable analyses demonstrated that decorticated CTI was independently associated with significantly increased odds of fusion (OR 4.11, 95% CI: 1.52 - 11.14, p=.006).
Conclusion : We found that decorticated CTI compared to non-decorticated TTI was independently associated with higher odds of fusion. Thus, navigated decortication and direct arthrodesis should be considered when performing MIS SIJF.