Patients with severe shoulder arthritis should weigh the associated benefits and risks when deciding whether or not to have shoulder replacement surgery.
Read more about Shoulder Osteoarthritis
Understandably, some patients may try to postpone surgery because of concerns about the associated risks. Others may postpone surgery because they do not want to outlive their original implant and have to undergo a second surgery. Postponing surgery, however, may lead to further damage the natural shoulder joint, making future surgery and recovery more challenging.
For example, postponing surgery may:
- Cause muscle atrophy from lack of use, making post-surgical rehabilitation more challenging
- Lead to excessive glenoid bone loss, complicating the surgeon's ability to resurface the socket side of the joint
Shoulder Replacements vs. Other Joint Replacements
Shoulder replacements, including total, reverse, and partial shoulder replacements, are the third most common joint replacement surgeries to be done in the US, following knee and hip replacements.
Shoulder replacements differ from hip and knee replacements, however, because the shoulder is not a weight-bearing joint and because of the shoulder's unique anatomy.
Of particular importance are the condition of the patient's shoulder socket and rotator cuff muscles before shoulder surgery.
The shoulder has a small, shallow socket
The shoulder joint's socket, called the glenoid, is shallow and small compared to the hip's pelvic socket. An average healthy glenoid is slightly concave and measures approximately 1 inch (2.7 cm) across and 1.7 inches (4.2 cm) high. The surgeon must make sure that this relatively small area of bone is healthy enough to receive a prosthetic.
Read more about types of prosthetics: Cemented vs. Cementless Alternatives in Joint Replacement
Before surgery, the doctor will order X-rays and possibly more detailed imaging, such as CT scans, to evaluate the glenoid bone stock and amount of wear. A patient whose glenoid shows signs of severe wear may not be eligible for replacing the socket side of the joint or may be given other surgical options, such as shoulder replacement with a bone graft.
Rotator cuff muscles help move and stabilize the shoulder
The shallow shoulder socket allows for an extremely wide range of motion, but it also increases dependence on the rotator cuff. The rotator cuff muscles, along with other soft tissue, "hug" the humeral head and glenoid together and keep the shoulder joint in proper alignment.
Some patients who have a large, chronic rotator cuff tear can develop "cuff tear arthropathy." Without an intact rotator cuff, the joint can become malaligned and develop arthritis. In addition to the pain from arthritis, these patients may lose the ability to raise their arm. In these cases, a surgeon may recommend a reverse shoulder arthroplasty. Reverse shoulder arthroplasty relies on the deltoid muscle rather than the rotator cuff muscles to help stabilize and move the shoulder joint.
Read more about Choosing Reverse Shoulder Replacement
Living with shoulder arthritis can be painful and frustrating. A patient who understands all of the available options can make an informed decision with their physician about the best course of treatment.