BackgroundContracture and thickening of the coracohumeral ligament (CHL) occur in patients with adhesive capsulitis. This adversely affects the movement and function of the shoulder joint. There is limited evidence that explores the effectiveness of an isolated steroid injection into CHL in combination with physical therapy. This prospective randomized control trial aimed to evaluate the clinical effects of ultrasound-guided corticosteroid injection compared to a sham injection into the CHL in subjects with adhesive capsulitis. MethodsForty patients (23 males, 52.2 ± 8 years of age) with unilateral adhesive capsulitis (with 5.4 ± 2 months mean duration of symptoms) were randomly assigned to either the experimental or control group. Both groups received ultrasound-guided injections into the CHL. The experimental group (n=20) received corticosteroids and the control group (n=20) received a sham lidocaine injection. All subjects underwent supervised conventional physical therapy three times a week for 3 months. Subjects were evaluated for improvements in pain, range of motion, and disability at 6 and 12 weeks as compared to pre-injection baseline measurements. Data were compared statistically across groups and times at p<0.05. The CHL thickness was compared at baseline across sides using paired t-tests. ResultsThe experimental group showed statistically greater improvements in pain, functional scores, flexion, abduction, internal and external rotation range of motion at 12 weeks compared to the control group. Pain reduction was observed in both groups at 6 and 12 weeks, but the experimental group exhibited significantly greater reductions. The CHL was significantly thicker on the affected side as compared to the unaffected side (p<0.001). Discussion and ConclusionThis study partially supported the hypothesis. Notably, significant improvements in pain, range of motion, and functional scores were observed at 12 weeks in the experimental group. The greater improvements in pain and external rotation may have resulted in lower disability scores in the experimental group. The results emphasize the importance of targeted intervention into the CHL.