Contrast dispersion pattern and efficacy of corticosteroid at the glenohumeral joint in adhesive capsulitis

Abstract

Background: Corticosteroid injection has a wide range of success in adhesive capsulitis but thereason for this has not yet been explained. We hypothesized that this difference might be due to thedistribution of the corticosteroids injected into the joint cavity because particulate steroid deposits inthe capsule and will not be moved over time by shoulder motion.Objectives: The purpose of this study is to determine whether the therapeutic efficacy of particulatecorticosteroid injection into the glenohumeral joint differs according to the dispersion pattern.Study Design: Prospective evaluation.Setting: Outpatient clinics at a tertiary university hospitalMethods: Seventy-two patients diagnosed as having adhesive capsulitis received a corticosteroidinjection at the glenohumeral joint. The posterior capsule and the subscapular bursa were selectedas dispersion sites and the dispersion of contrast dye was expressed as a ratio (%). Two weeksand 3 months after the injection clinical improvement (“not improved,” “slightly improved,” “muchimproved”), numeric rating scale (NRS), and passive range of motions (PROM) were evaluated. Thedispersion of the contrast dye was compared according to the clinical improvements by an analysisof variance test. Pearson correlation test was done to find the relationship between PROM and thedispersion and between change of NRS and the dispersion.Results: The distribution in the subscapular area was 30.0% in the “much improved” group,22.0% in the “slightly improved” group, and 37.1% in the “no improvement” group which wasnot significantly different (P = 0.179). Correlations between changes of NRS and the dye distributionwere not statistically significant (P = 0.429 at 2 weeks and P = 0.629 at 3 months).The change of passive external rotation 3 months after the injection was significantly correlated withthe dye distribution (P = 0.035).Limitations: Because of diverse pathologic findings in adhesive capsulitis, further studies will beneeded to address the effect of the dye distribution on the pain improvement according to pathologicfindings revealed by magnetic resonance imaging (MRI).Conclusion: External rotation of the shoulder in adhesive capsulitis has greater improvement asthe corticosteroid solutions injected into the glenohumeral joint are increasingly dispersed to thesubscapularis area. However, this does not affect the pain improvement after the injection.