Adhesive capsulitis, also known as frozen shoulder, is a condition associated with shoulder pain and stiffness. There is a loss of the ability to move the shoulder, both voluntarily and by others, in multiple directions. The shoulder itself; however, does not generally hurt significantly when touched. Muscle loss around the shoulder may also occur. Onset is gradual over weeks to months. Complications can include fracture of the humerus or biceps tendon rupture.
The cause in most cases is unknown. The condition can also occur after injury or surgery to the shoulder. Risk factors include diabetes and thyroid disease. The underlying mechanism involves Inflammation and scarring. The diagnosis is generally based on a person’s symptoms and a physical exam. The diagnosis may be supported by an MRI.