IS'ECHO : Impact of Bursitis on the Efficacy of Subacromial Steroid Injection in Rotator Cuff Tendinopathy

Patients referred to receive a subacromial ultrasound-guided injection for shoulder pain related to a rotator cuff tendinopathy will be enrolled in the study. After validation of the inclusion criteria, the participants will receive oral information about the protocol. Then, they will be examined and will undergo X-rays and an ultrasound of their shoulder. Pain shoulder and shoulder disability will be assessed before the injection with a visual analogic pain scale and the Oxford Shoulder Score questionnaire, respectively. The subacromial injection will be performed under ultrasound guidance to accurately inject the subacromial bursae. After skin disinfection with povidone, the injection will be performed with a 21G needle. The bursae will be injected with 2 ml of lidocaine 2% and 1 ml of betamethasone. After the procedure, the participants will all receive a standardized physiotherapy. For primary outcome, the therapeutic response will be assessed 3 months after the procedure. Patients will be considered as having a good response if their level of pain decreases by over 30%. The number of participants having a good clinical response will be compared between the patients presenting a bursitis and those without bursitis. The comparison will be made using a Chi-2 test. Others parameters will be studied: reduction in pain 6 weeks after the injection, reduction in shoulder disability 6 weeks and 3 months after the injection. Other ultrasound lesions will be collected so as X-ray features to search other factors associated with the presence or absence of a good therapeutic response (details in secondary outcomes).