Shoulder Replacement Surgery
What is Shoulder Arthroplasty?
If your shoulder becomes damaged, your healthcare provider may recommend surgery to replace all or part of the shoulder joint. This procedure, known as shoulder arthroplasty, removes damaged areas of the bone and replaces them with prosthetic components made of metal and plastic. Since damage to the shoulder joint can cause pain and weakness, the purpose of shoulder arthroplasty is to relieve pain and improve range of motion.
The shoulder is a ball-and-socket joint. The bone in your upper arm (humerus) has a ball (humeral head) that fits into a socket (glenoid), which is the curved structure on the outside of your shoulder blade. The shoulder has several structures that stabilize the joint: a ring of cartilage that deepens the socket and reduces friction, ligaments that attach bone to bone, and tendons that connect muscles to the bone.
If you have a condition that makes it painful to use your shoulder, and physical therapy is not effective at alleviating pain or restoring normal mechanics to the shoulder, shoulder replacement surgery may be the next step.
When is Shoulder Arthroplasty Indicated?
A shoulder replacement may be indicated when there is persistent pain, loss of strength, and reduced range of motion. There are several conditions that can damage the joint and lead to the consideration of shoulder joint surgery.
- Osteoarthritis: Frequently referred to as wear-and-tear arthritis, this disease is most often seen in patients over 50. It causes the cartilage that cushions the bones of the shoulder joint to wear away. Without that cushion, the bones rub against together and the joint becomes stiff and painful. Since there is no way to prevent the progression of osteoarthritis, patients with this condition may eventually need shoulder surgery.
- Rheumatoid arthritis: This is the most common form of a group of conditions called inflammatory arthritis, which is caused by an overactive immune system. Chronic inflammation damages the cartilage, leading to cartilage loss, joint pain and stiffness.
- Post-traumatic arthritis: This condition, which is usually temporary, develops after an injury. If there is a fracture or dislocation of one of the bones that make up the shoulder joint, you can develop arthritis. Sometimes, post-traumatic arthritis can become a chronic condition where surgery might be necessary to alleviate pain.
- Rotator cuff tear arthropathy: Your arm is kept in your shoulder socket by a group of muscles and tendons called the rotator cuff. A severe tear in the rotator cuff can lead to rotator cuff tear arthropathy (arthritis due to an untreated rotator cuff tear). This condition is characterized by the permanent loss of the rotator cuff tendons, pain, and diminished function.
- Osteonecrosis: Also known as avascular necrosis, this condition limits blood supply to the bone. This causes the bone cells to die and the bone to collapse. Risk factors for this disease include chronic steroid use, heavy alcohol use, severe shoulder fracture, sickle cell disease and deep sea diving.
- Severe fracture: Many patients who have sustained a severe shoulder fracture have osteoporotic bone. If the humeral head is shattered, the blood supply to the bone pieces may be interrupted. In this circumstance, a shoulder replacement may be indicated. If a prior shoulder fixation fracture surgery has failed, the humerus may require replacement.
- Three Approaches to Shoulder Arthroplasty
Depending on the condition causing shoulder pain and dysfunction, and the type of damage to your joint, your healthcare provider may recommend one of the following three shoulder replacement options.
- Anatomic Defined: In an anatomic total shoulder replacement, both the ball and socket are replaced. An anatomic replacement requires that the rotator cuff muscles are intact or repairable.
- Reverse Defined: If the rotator cuff is severely damaged, your doctor may recommend a reverse total shoulder replacement. Similar to an anatomic total shoulder replacement, both the ball and socket are replaced. However, in this approach, the implants are reversed. They are placed opposite of where the ball and socket are naturally located. This means that the ball is attached to the shoulder blade, while the socket is attached to the humerus, where it is supported by a metal stem.
- Partial Defined: If just the ball side of the joint is damaged, a partial shoulder replacement may be recommended. In this approach, only the humeral head is replaced.
After shoulder surgery, most patients have no pain and many have regained strength and an improved range of motion.