Yonsei Med J.  2025 Feb;66(2):103-110. 10.3349/ymj.2023.0634.

Impact of Distal Fusion Level on Sacroiliac Joint Degenerative Change Following Adolescent Idiopathic Scoliosis Surgery

• Kim SH
• Shin JW
• Moon SH
• Suk KS
• Park SY
• Lee BH
• Kwon JW
• Ha JW
• Park Y
• Kim HS

• KMID: 2564723
• DOI: http://doi.org/10.3349/ymj.2023.0634

Abstract

Purpose
To evaluate the relationship between distal fusion level in correction and fusion surgery for adolescent idiopathic scoliosis (AIS) and radiologic changes in the sacroiliac (SI) joint.
Materials and Methods
This retrospective cohort study evaluated patients who underwent correction and fusion for AIS between 2005 and 2017 with at least 5 years of follow-up. We categorized patients into two groups: Group 1 (distal fusion above L2, 74 patients) and Group 2 (distal fusion at L3 and below, 52 patients). Radiologic parameters and SI joint changes were evaluated on plain radiographs obtained from preoperative to 5 years postoperatively. We also investigated other risk factors for SI joint change.
Results
Analysis of demographic factors revealed no significant difference between the two groups. There was a significant difference in the incidence of SI joint change between Group 1 (5 patients, 6.75%) and Group 2 (18 patients, 34.61%), with Group 2 showing a faster increase in incidence according to the Kaplan-Meier method (p<0.0001). Preoperative lumbar lordosis (LL) and ΔLL had a significant relationship with SI joint changes [preoperative LL, hazard ratio (HR)=0.77, 95% confidence interval (CI)=0.64– 0.93, p=0.008; ΔLL, HR=0.79, 95% CI=0.67–0.95, p=0.01).
Conclusion
After AIS surgery, patients who had fusion to the lower lumbar vertebrae (L3 or L4) experienced a higher incidence and faster progression of degenerative changes in the SI joint. Low preoperative LL and inadequate correction of LL during the operation were also risk factors for SI joint degeneration.

Keyword

Adolescent idiopathic scoliosis; postoperative pain; sacroiliac joint; distal fusion level