Frozen shoulder, also known as adhesive capsulitis, is a condition affecting the joints of the shoulder causing pain and stiffness. Frozen shoulder begins gradually, worsens over time, and then generally resolves. There are four main stages to the condition:
1. Painful stage
2. Pain and freezing stage
3. Frozen stage
4. Thawing stage.
These will be discussed in more detail in Part 3. The shoulder joint is a ball and socket joint. The ball is the upper end of the long bone of the arm and the socket is attached to the shoulder blade. The ball and socket joint is connected with a tissue called the joint capsule. This joint capsule is lined with a connective tissue called the synovium. It is thought that the first stage of frozen shoulder is an inflammatory condition of this lining or synovium and this progresses to a thickening of the joint capsule or fibrosis.
Frozen Shoulder Part 2 will discuss the causes and risk factors.
Reference:
1. American Academy of Orthopaedic Surgeons website available at: https://orthoinfo.aaos.org/en/diseases–conditions/frozen-shoulder
2. Kelley MJ et al Shoulder pain and mobility deficits: Adhesive capsulitis. J Orthop Sports Phys Ther 2013; 43(5): A1-A31.