Minimally invasive sacroiliac joint fusion secondary to lumbosacral fusion: Clinical and functional results at 2 years of follow-up

Introduction

Degenerative sacroiliac (SI) joint syndrome is known to be more common after lumbosacral fusion. While this diagnosis is suspected based on various clinical criteria and diagnostic tests, it is confirmed with a diagnostic nerve block. If conservative treatment fails, SI joint fusion through a minimally invasive approach is a useful palliative approach for patients at a treatment crossroads. The aim of this study was to evaluate the clinical and functional results at 2 years postoperative after minimally invasive SI joint fusion in patients with SI joint syndrome following lumbosacral fusion.

Materials and methods

We carried out a single-center retrospective study of patients operated between June 2017 and October 2020. Included were patients who had a confirmed diagnosis of SI joint syndrome after lumbosacral fusion surgery, who underwent SI joint fusion and had at least 2 years’ follow-up. The primary outcome was the improvement in lumbar and radicular pain on a numerical rating scale (NRS). The secondary outcomes were the functional scores (Oswestry and SF-12) along with the level of patient satisfaction. Our study population consisted of 54 patients (41 women, 13 men) with a mean age of 59 years (27–88). Thirty-one of these patients were operated on both sides (85 fusions in all). The patients had undergone a mean of 3 lumbar surgeries (1–7) before the SI fusion.

Results

The lumbar and radicular NRS were 8.4 (7–10) and 5.1 (2–10) preoperatively and 5.2 (0–8) and 3.0 (0–8) at 2 years postoperatively, which was a reduction of 37% and 42% (p < 0.001), respectively. The Oswestry score went from 69.4 (52–86) preoperatively to 45.6 (29–70) at 2 years, which was a 33% improvement (p < 0.001). Eighty-six percent of patients were satisfied or very satisfied with the surgery.

Discussion

After minimally invasive SI joint fusion, the patients in this study had clear clinical and functional improvements. Previous publications analyzing the results of SI joint fusion found even more improvement, but those patients were relatively heterogenous; in our study, only patients who had a history of lumbosacral fusion were included.

Conclusion

Minimally invasive SI joint fusion helped patients who developed SI joint syndrome after lumbosacral fusion to improve clinically and functionally.

Level of evidence

IV, retrospective study.