Image-guided versus blind glucocorticoid injection for shoulder pain

Abstract

Background: Traditionally, glucocorticoid injection for the treatment of shoulder pain has been performed guided by anatomical landmarks alone. With the advent of readily available imaging tools such as ultrasound, image-guided injections have increasingly become accepted into routine care. While there is some evidence that the use of imaging improves accuracy, it is unclear from current evidence whether or not it improves patient-relevant outcomes.

Objectives: The aim of this review was to assess whether image-guided glucocorticoid injections improve patient-relevant outcomes compared to landmark-guided or systemic intramuscular injections in patients with shoulder pain.

Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, via The Cochrane Library), MEDLINE (Ovid), and EMBASE (Ovid) to June 2011. We also searched the World Health Organisation International Clinical Trials Registry Platform (http://www.who.int/trialsearch/Default.aspx) to identify ongoing trials and screened reference lists of retrieved review articles and trials to identify potentially relevant studies.

Selection criteria: We included randomised controlled trials (RCTs) and quasi-randomised controlled clinical trials that compared image-guided glucocorticoid injection to landmark-guided or systemic intramuscular injection. Outcomes of interest included pain, function, range of motion, proportion of participants with overall improvement and adverse events. There were no restrictions on language or date of publication.

Data collection and analysis: Two review authors independently selected the studies for inclusion, extracted the data and performed a risk of bias assessment. Disagreement about inclusion or exclusion of individual studies and risk of bias was resolved by a third review author.

Main results: Five studies (290 participants) were included in the review. The image-guided groups in all trials used ultrasound to guide injection. Four studies included participants with rotator cuff disease; in three the comparator was local landmarks to direct injection into the subacromial bursa and in the fourth the comparator was systemic intramuscular injection into the upper gluteal muscles in the buttock region. One study included participants with adhesive capsulitis and injection was directed into the glenohumeral joint by either ultrasound or anatomical landmark guidance.No significant differences between groups were observed with respect to reduction in pain at one to two weeks (two trials, 146 participants, standardized mean difference (SMD) -1.44, 95% CI -4.14 to 1.26), or function at one to two weeks (two trials, 146 participants, SMD 0.95, 95% confidence interval (CI) -1.29 to 3.20; back-translated to mean difference (MD) 4 points, 95% CI -5 to 13, on a 0 to 100 point scale, higher score means better function) or six weeks (three trials, 207 participants, SMD 0.63, 95% CI -0.06 to 1.33; back-translated to MD -3 points, 95% CI -11 to 5, on a 0 to 100 point scale) and the sensitivity analyses did not alter these results. While there was a significant difference between groups with respect to reduction in pain at six weeks favouring image guidance (three trials, 207 participants, SMD -0.80, 95% CI -1.46 to -0.14), there was considerable statistical heterogeneity and after removing trials with inadequate allocation concealment and inadequate blinding in a sensitivity analysis, the difference was no longer significant (one trial, 106 participants, MD -0.60 points, 95% CI -1.44 to 0.24 points on a 9-point scale).No statistical difference in adverse events between groups was identified (10/104 image-guided group versus 16/103 comparator; risk ratio (RR) 0.55, 95% CI 0.17 to 1.85). Minor adverse events reported included transient post-injection pain, facial redness and warmth.

Authors' conclusions: Based upon moderate evidence from five trials, our review was unable to establish any advantage in terms of pain, function, shoulder range of motion or safety, of ultrasound-guided glucocorticoid injection for shoulder disorders over either landmark-guided or intramuscular injection. The lack of any added benefit of ultrasound guided subacromial bursal injection over glucocorticoid injection administered into the upper gluteal muscles of the buttock suggests that the benefits of glucocorticoid may arise through systemic rather than local effects. Therefore, although ultrasound guidance may improve the accuracy of injection to the putative site of pathology in the shoulder, it is not clear that this improves its efficacy to justify the significant added cost.