Shoulder Arthritis

Shoulder osteoarthritis is the gradual wearing of the smooth cartilage that lines the ball-and-socket joint at the center of the shoulder. As that surface thins and roughens, the bones no longer glide cleanly, and the joint becomes stiff and painful. It cannot be cured, but it can be managed. Most cases build up over years without a single cause, and rotating the arm inward to reach behind the back is usually the first motion to go.

Symptoms come on slowly and build over months to years. Common symptoms include:

• A deep ache that worsens with activity and, in more advanced arthritis, may disturb sleep
• Stiffness, with loss of the motion that reaches the arm behind the back
• Trouble reaching overhead, lifting, or sleeping on the affected side
• A grinding or crunching sensation with movement

Diagnosis starts with an examination for the deep ache, the grinding with motion, and the gradual loss of inward rotation. X-rays usually confirm it, showing the joint space narrowing and bone spurs. An MRI or CT is often added when a replacement is being considered, to show how worn the socket is and whether the rotator cuff is intact.

Most people start with nonsurgical care and stay with it for years:

• Activity changes to ease overhead lifting and the motions that load the joint
• Physical therapy to preserve motion and strengthen the surrounding muscles
• Anti-inflammatory medication for pain and inflammation
• A corticosteroid injection to calm pain for weeks to a few months

Surgery is considered when arthritis significantly limits daily life and nonsurgical care no longer controls the pain. For the shoulder, that usually means a shoulder replacement that replaces the worn ball and socket with new joint surfaces. The right type depends largely on whether the rotator cuff is intact.

• Total shoulder replacementShoulder

For a fuller explanation, including anatomy, diagnosis, and the full range of treatment:

• Arthritis of the Shoulder — AAOS OrthoInfo