Is Adding Extracorporeal Shock Wave Therapy to Physiotherapy and Corticosteroid Injection Beneficial for Frozen Shoulder

Frozen shoulder, or adhesive capsulitis of the shoulder, is a common clinical problem characterized by pain, loss of both passive and active range of motion (ROM) of glenohumeral joint (GHJ), leads to functional limitation, and reduces quality of life. Primary frozen shoulder occurs without any obvious connection to any other condition, and secondary frozen shoulder is related to some medical problems, such as an injury, inflammatory, immunological, and endocrine conditions, or surgery of the shoulder. The prevalence of frozen shoulder is 2%-5% in general population, usually between 40 to 60 years old, and more in female. Diabetes patients have more chance of developing frozen shoulder than general population and the prevalence was 13.4%. Frozen shoulder is clinically divided into 3 overlapping phases. The painful freezing phase has a duration of 10 to 36 weeks and is characterized by pain and stiffness around the shoulder, which may worsen at night. The frozen phase is characterized by restricted ROM with a gradual relief of pain, which occurs at 4 to 12 months. The thawing phase with spontaneous improvement in the ROM takes 12 to 42 months. .Although frozen shoulder is a self-limited condition, the recovery may be slow and incomplete. Treatment of frozen shoulder consists of physiotherapy, oral medication (nonsteroidal anti-inflammatory drugs or corticosteroid), intra-articular corticosteroid injection, hydrodilatation, suprascapular nerve block, mobilization, manipulation under anesthesia, and operative intervention (arthroscopic release or open release). Because of the uncertainty of the efficacy and risk of surgical treatment, nonsurgical treatments are more likely chosen by patients. Among them, intra-articular steroid injection and physical therapy are commonly used nonsurgical treatments and have shown some benefits. .Because the clinical picture of frozen shoulder may be similar to, or combining with chronic subacromial bursitis, especially in the freezin