Additional Operations Following Sacroiliac Joint Fusions: A Minimum 3-year Follow-up Cohort Study of Patients Operated for Chronic Sacroiliac Joint Pain.

Methods: A retrospective analysis of prospectively collected registry data. Objective: To examine the subsequent pattern of surgeries and outcome of sacroiliac joint fusions (SJF) in patients previously operated in the lumbar spine as well as those scheduled for primary SJF.

Background: Patients with SI joint pain often have a history of previous back surgery, but it is unclear how often patients require back surgery after SI-joint fusion.

Methods: We obtained data from the national Swedish spine registry on all patients who underwent a SJF between 1998 and 2019 and identified previous and additional operations of any type after a SJF between 1998 and 2022. The EuroQol EQ VAS and the Oswestry disability index (ODI) were registered preoperatively and 1 year after the last undergone surgery. Satisfaction with treatment was assessed 1 year after surgery.

Results: Two hundred seventy-nine patients underwent SJF between 1998 and 2019. Ninety-five of 279 patients (34%) underwent primary SJF, and 184 of 279 patients (66%) underwent SJF after spine surgery. Forty-one of 95 patients (43%) underwent additional spine or SI-joint surgery after a primary SJF. The most common additional procedure was contralateral SJF (22 of 41; 54%). The mean EQ-VAS change after primary SJF was 19 points (95% CI 12-26), whereas the corresponding value for SJF after previous lumbar spine surgery was 9 points (95% CI 2-16). The corresponding values for the mean ODI change were -14 points (95% CI -19 to -10) and -9 points (95% CI -14 to -4) respectively. Seventy-three percent (37 of 51) and 54% (34 of 63) were satisfied after SJF after primary versus secondary SJF.

Conclusions: After primary SJF most additional surgeries are for contralateral symptoms and 9% required lumbar surgery after their SJF. Two-thirds of the patients with SJF have had their surgery after lumbar surgery.