Posterior Sacroiliac Fusion Surgery: A Retrospective Single Center Study

Background: Chronic sacroiliitis has variable etiologies with numerous treatments of varying efficacy. In recent years, a novel posterior approach utilizing bone matrix has been developed although to date, there is limited data in the literature regarding efficacy and safety through this approach. Benefits described include reduced adverse outcomes and quicker recovery when compared to the lateral approach. Objective: The present investigation focused on sacroiliac joint fusion through the posterior approach and outcomes including disability, pain, and use of analgesics post-surgery. Study Design: This retrospective, single-center study was conducted evaluating safety and efficacy of sacroiliac fusion allograft implants (LinQ Implant System from PainTEQ; PsiF System from Omnia Medical). Methods: A total of 72 posterior approach sacroiliac joint fusions were performed. Fifty-three individuals were enrolled and followed at LSU Health Shreveport as the sole investigational site between August 2020 and June 2024. Selected participant age ranged between 28 and 79 years, with a mean age of 53.4 years. The LinQ Implant System was the primary surgical hardware selected for implantation (83.0%), with the PsiF System chosen in the remaining cases. Outcome Measures: VAS Scores, disability changes, adverse outcomes, and analgesic use were compared after sacroiliac joint fusion via the posterior approach. Results: Mean VAS Scores for SIJ Pain Intensity significantly decreased by 3.6 cm from a baseline score of 9.5 cm by the Specified End (June 1st, 2024). In this regard, 65.4% of patients experienced a 20% or greater improvement in pain, 38.5% of patients experienced a 50% or greater improvement in pain, and 26.9% of patients experienced a 70% or greater improvement in pain. Zero (0) procedure-related adverse events nor intra- or post-operative complications occurred throughout the duration of the investigation. Limitations: Retrospective nature of the study without a control group. Fifty-four percent (39 of 72) completed minimum one year follow up. Further, the withdrawal rate was 26%. Conclusion: The results of the present investigation demonstrated effective outcomes with minimal adverse effects and improvements in disability over a three-year period in the largest single center study to date involving posterior approach sacroiliac joint fusion.