Predictors of 3-month response to US-guided sacroiliac joint injection: a prospective study of diagnostic block-confirmed patients.

BACKGROUND

Sacroiliac joint (SIJ) pain is a prevalent yet underappreciated source of LBP, with multiple etiologies and therapeutic options. Failure of the conservative approach necessitates interventional injections, especially with sonographic guidance to ensure precision of needle placement.

METHODS

One hundred patients with isolated moderate SIJ pain were injected anesthetic and steroids with US guidance after failure of conservative measures. Those who attained immediate pain improvement > 50% were prospectively followed up for 3 months to determine the true responders and depict different patients' characteristics predicting this response.

RESULTS

In the univariate analysis manual work, high BMI, pain referred below the knee, and pre-injection MODQ were statistically significant predictors of failed pain improvement, whereas BMI and pre-injection MODQ were statistically significant predictors of failed function improvement. After multivariate analysis, obesity and pain referral below the knee were statistically significant predictors of failure of pain improvement. Successful pain and function improvement was significantly predicted by immediate post-injection improvement in VAS ≥ 80%.

CONCLUSIONS

Individualized treatment plans are essential based on patients' characteristics rather than symptoms and pathology.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06684938/11 November 2024. Key Points • Patients with sacroiliac pain radiating below the knees were less likely to respond to sacroiliac joint injection. • Obese patients with sacroiliac pain were more likely to experience recurrence of their symptoms after SIJ injection.