Comparison of the Effect of Combined Glenohumeral Joint and Subdeltoid Bursa Injection With Platelet-rich Plasma (PRP), Corticosteroid, and Normal Saline in Addition to Physical Therapy for Treatment of Frozen Shoulder

This is a prospective assessor-blinded randomized controlled trial. We plan to enroll 90 participants with frozen shoulder from the outpatient clinic of the Department of Physical Medicine and Rehabilitation in our hospital. The study protocol and consent form have been approved by our ethics committee. After detailed explanation about the content of this study, participant is asked to sign an informed consent. The patients will be randomly divided into three groups: 1). PRP injection (PRP group); 2). Corticosteroid injection (CS group); 3). Normal saline injection (NS group). Randomization will be assigned according to a random number from a computer program by a statistician. The patients and the evaluator are unknown which group the patients are allocated, but the physician who performs joint injection knows which group the patients are assigned.