The joint surfaces of the upper arm bone and the socket of the shoulder blade (head of the humerus and glenoid) are removed to make room for the joint replacement. The shoulder joint replacement can be done in different ways depending on type of disease present and the amount of joint damage.
Either a metal stem is fixed into the arm bone (humerus), to which a metal replacement ball is attached. Or a metal cap is inserted over the ball of the shoulder joint (humeral head).
The replacement ball is made in different sizes and can be adjusted into the correct position to provide an accurate match to your arm bone (humerus). Replacing the head of the humerus only is called a Hemiarthroplasty. In addition, a replacement socket may be used. It is made of plastic, which is either fixed to a metal back plate before it is fitted into the bone in the socket (glenoid) or inserted, with or without a special bone cement, directly into the bone.
A Healthy Shoulder An Arthritic Shoulder
Replacing both the head of the humerus and the glenoid is called a Total Shoulder Replacement. This results in a new metal on bone, or metal on plastic, joint that can move smoothly again, and so does not hurt when you move your arm. The parts of a replacement are often called prostheses, components, or implants.
Shoulder replacement surgery usually lasts about two hours. The incision for the surgery is usually about four to six inches long and the incision is made along the front of the shoulder joint. The surgery is most commonly done under general anesthetic.
The scar is positioned on the front of the shoulder. This makes it relatively easy to conceal and a lot of care is taken to make the scar as cosmetically attractive as possibble. The scar is normally about 8 - 12cm in length.
You may be wearing a shoulder sling when you come back from theatre. Wear it as your consultant or physiotherapist instructs you to. The time it takes to return home depends on many factors and your surgeon will advise you.