Shoulder replacement is a treatment for endstage arthritis of the shoulder joint. If a patient has failed nonoperative treatment, (physical therapy, medications, injections, rest), shoulder replacement becomes a surgical alternative to relieve pain. The procedure involves replacing the shoulder joint with metal and plastic to alleviate the pain from bone on bone arthritis and improve function.
The normal shoulder is a ball and socket joint (Figure 1). The ball is called the humeral head and the socket is called the glenoid. In shoulder arthritis, the cartilage (gliding surface for the joint) is destroyed by wear and tear, inflammation, previous injury, or failed previous shoulder surgery. The hallmarks of shoulder arthritis are chronic pain exacerbated by shoulder activity and limited range of motion. In addition, there is difficulty sleeping on the affected shoulder and an inability to perform simple tasks without pain.
Initial treatment for shoulder arthritis should include the following conservative treatment measures:
Shoulder arthritis has several different causes.
Surgery is performed arthroscopically in the outpatient setting. General or nerve block anesthesia is administered. Three to four small incisions (5 mm) are made in the shoulder to allow a camera and specialized instruments into the shoulder. Inflamed bursa and bone spurs are removed arthroscopically, creating space for the rotator cuff muscles and eliminating impingement. Suture anchors are utilized for the repair. Suture anchors are small metal or bioabsorbable screws that have two sutures each attached to them. The suture anchors are inserted in bone and the sutures are then used to sew the tendons to bone arthroscopically.
Each type of shoulder arthritis has specific features that are unique that affect planning of surgery and the type of shoulder replacement needed. Based on physical examination, X-ray, and MRI or CT scan, your doctor will usually know what type of arthritis you have and whether or not you are a candidate for a shoulder replacement.
A normal shoulder has cartilage on the ball and socket to enable smooth gliding motion (Figure 2). In the arthritic shoulder the normal cartilage is worn away instead of cartilage gliding smoothly on cartilage, bone rubs roughly against bone, creating pain and inflammation. A shoulder replacement consists of a metal stem and ball that resurfaces the arthritic humerus bone (ball) and a plastic component that resurfaces the arthritic glenoid (socket), (Figure 3).
In a patient with arthritis, shoulder X-rays show joint space narrowing and osteophyte formation (bone spurs) (Figure 4). When the rotator cuff is intact and bone stock is good, a conventional shoulder replacement replaces the ball and socket joint with metal and plastic, eliminating pain and restoring range of motion (Figure 5).
DAY OF SURGERY/HOSPITAL STAY
The complication rate for shoulder replacement is low. However, as with any joint replacement, the pain and disability must be significant enough to warrant surgery. Complications can include:
Shoulder replacement is for severe pain and shoulder functional limitations that affect daily life. Prior to undergoing a shoulder replacement, you should have tried physical therapy, injections, medications, activity modification and watchful waiting, all without improvement. Only you can decide when is the right time for a shoulder replacement.
Although there are risks of shoulder replacement surgery, results are generally excellent in the properly selected patient with sufficient bone stock and an intact rotator cuff.