Pre-operative Sacroiliac Joint Pain in Adult Spinal Deformity Patients: Incidence, Associated Factors, and Rates of Resolution with Surgery from a Prospective Multicenter Database

Abstract

Introduction: The sacroiliac joint (SIJ) is a potential source of pain in the ASD population. Incidence and predictors of pre-operative SIJ pain and rates of resolution with surgery in the ASD population are not well-understood.

Methods: A prospective, multicenter database of surgically-treated ASD patients was queried for baseline SIJ pain at the pre-operative assessment. SIJ pain was defined as self-reported back pain in the posterior superior iliac spine region scored ≥4 out of 10 and ≥3 of 5 positive provocative SIJ maneuvers. Demographic data, spinal alignment parameters, and health assessments were assessed using Wilcoxon and Chi-squared analysis. Predictors of pre-operative SIJ pain were assessed with univariate and multivariate logistic regression.

Results: 735 patients were included with a mean (SD) age of 61.3 (15.3) years, BMI of 27.6 (5.4), Edmonton Frailty Score (EFS) of 3.4 (2.5), and Charlson Comorbidity Index (CCI) of 1.1 (1.8). 65% were female and 6% were tobacco users. 411 patients had self-reported PSIS pain and 53 patients (7.2%) had pre-operative SIJ pain as assessed by SIJ maneuver testing. SIJ pain was not associated with history of prior lumbosacral fusion (P=0.23). Patients with SIJ pain had higher BMI (30.0 v. 27.4, P=0.004), pre-operative pain medication usage (92.5% v. 77.7%, P=0.02), EFS (4.6 v. 3.3, P<0.001), and CCI (1.6 v. 1.0, P=0.006) as well as lower L4-S1 lordosis (28.7 v. 34.5, P=0.02) and greater L1 pelvic angle (14.5 v. 10.8, P=0.03). After variable selection with univariate regression, multivariate logistic regression identified higher BMI (OR 1.06, P=0.033) as a significant predictor of SIJ pain at pre-operative. In the patient cohort with SIJ pain at pre-operative, 91.7% reported no SIJ pain at 1 year follow-up. 11/53 (20.8%) patients with baseline pain and SIJ fusion performed concurrently with ASD surgery had 100% resolution of SIJ pain in this cohort; however there was no significant difference in pain resolution between patients with SIJ fusion and those without (P=1).

Conclusion: We found a lower prevalence of preoperative SIJ pain in ASD patients than historically reported, present in 7.2% of patients. Higher BMI was a predictor of pre-operative SIJ pain in this population. ASD surgery led to resolution of SIJ pain in >90% of patients at 1-year follow-up.

Keywords: adult spinal deformity; sacroiliac joint; sacroiliac joint pain.