Osteoarthritis of the shoulder
The shoulder joint is unique in that the ball of the upper arm bone (the humeral head) is two times larger than the socket of the shoulder blade (the glenoid). This creates a very mobile joint, but demands an extensive array of tendons, ligaments and muscles to keep the joint together. These together allow the smooth movement found in the healthy shoulder.
The main shoulder joint (the glenohumeral joint) allows more movement than any other joint in the body. It is responsible for one to raise their arm, to put their arm up their back and to bring it out to the side.
Unfortunately a joint like this can wear out like any other joint in the body and can therefore develop arthritis. This causes pain and joint destruction.
The following three types of arthritis are the most common sources of joint damage seen in the shoulder:
How do patients present?
One also often does a CT scan to confirm the degree of damage to the joint. Once the condition has been diagnosed then treatment generally depends on the severity of the symptoms.
How are these problems treated?
Total shoulder replacement or shoulder arthroplasty is the replacement of the ball of the upper arm and socket of the shoulder blade with specially designed artificial parts, called prostheses, made of metal and polyethylene (a medical-grade plastic). The humeral (upper arm) prosthesis consists of a metal ball that replaces the head of the humerus, and a body and stem that is secured into the upper arm bone. The glenoid (shoulder blade socket) prosthesis is made of a special polyethylene, and is designed to replace the socket part of the joint.
There are two types of shoulder replacement procedures. If only the metal humeral components are used, the procedure is called a hemi-arthroplasty. If both the humeral components and the glenoid prosthesis are used, then the procedure is called a total shoulder arthroplasty. The surgeon determines whether you have a total shoulder replacement or hemiarthroplasty depending on your age and whether your rotator cuff tendon is intact and working.
How is the operation done?
In the operation only one tendon needs to be cut for the surgeon to get to the shoulder joint. Your shoulder is dislocated at the time of surgery and the ball of the humerus is replaced by a metallic head and stem. The glenoid or scapula is replaced with a polyethylene prosthesis that is cemented into the bone. The surgeon will use the ones that best resemble your bones at the time of surgery. The joint will then be relocated and put through a series of movements to make sure it is stable. When the surgeon is happy the tendon at the front of your arm is stitched back in place. Your wound is then closed and you are placed in a sling. You will return to the ward in a sling and with a drain to remove any excess blood. After 24 hours the tubing is removed and we will start gentle movement of your arm with physiotherapy.
Complications related to the surgery can occur but are quite rare. A general anaesthetic is used and there are risks related to this. Some of the risks include infection, nerve and blood vessel damage, loosening of the prosthesis, fracture at the time of surgery, dislocation, stiffness and ongoing pain, deep vein thrombosis or pulmonary embolism and the need for revision surgery.
Before and after shoulder replacement
- Pathway for total hip replacement and resurfacing hip replacement
- Bearings for hip replacement
- Hip replacement in the young