Avascular Necrosis of the Shoulder
This refers to the disruption of the blood supply to the humeral head (the ball part of the shoulder joint). This occurs for several reasons including injury/fractures, long term use of steroids and alcohol, and sickle cell crisis. It can also occur in divers after developing the bends. Its presentation depends on the stage. Early stages can present with pain. Xrays may be normal with this but it may be identified with an MRI. Later stages present with pain and restriction in movement. Xrays may show flattening or collapse of the bone at the humeral head. Very late stages will present with arthritis on Xrays. The age will vary depending on the cause.
The initial treatment involves addressing the underlying cause, analgesia, activity modification and muscle strengthening exercises. Surgical treatment for the late stages often involve arthroplasty.