Ultrasound-guided Subacromial-subdeltoid Bursa Steroid Injections: Retrospective Comparison of Two Approaches and the Assessment of Impingement Tests to Predict Efficacy.

Objective: Compare the efficacy of two approaches to ultrasound-guided subacromial-subdeltoid bursa injections and to assess whether shoulder impingement tests acts as a predictive factor for efficacy of the injection.

Design: Retrospective chart review and telephone survey of 40 patients who received ultrasound-guided subacromial-subdeltoid injections using 4cc 1% lidocaine and 80 mg methylprednisolone from January 2011 to December 2011. Outcome measures included: number of positive shoulder impingement tests (Neer, Hawkin, Yocum), pain level (10-Point VAS) and duration of pain relief (< 4 weeks, 4-12 weeks, > 12 weeks).

Results: Nineteen patients received the injection through an anterior-superior approach, while 21 patients received the injection through a posterior approach. Mean reduction of the VAS score with the anterior-superior approach was 3.42 (SD-2.36); the posterior approach was 4.71 (SD-2.70). There was no significant difference in the mean reduction of the VAS score between the two groups (p = 0.11). Mean reduction of the VAS score after injection for patients with one positive impingement test was 2.57 (SD-3.04), two positive impingement tests was 4.47 (SD-2.50) and three positive impingement tests was 4.50 (SD-2.46). Single-factor analysis of variance (ANOVA) analysis revealed a p-value of 0.22. The number of impingement signs had a statistically significant effect on duration of pain relief (p = 0.01).

Conclusion: There was no statistically significant difference in the efficacy measured by change in the VAS score or the duration of relief between the two ultrasound-guided approaches to the subacromial-subdeltoid injection. The number of positive impingement tests on physical examination had a significant effect on duration of pain relief from the injections.