Conditions Treated by Surgery
Shoulder replacement is much less common than hip or knee replacement. While approximately 23,000 people a year in the U.S. have shoulder replacement, 400,000 will have their knees replaced and over 300,000 will replace their hips. Nonetheless, shoulder replacement surgery is used to treat osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, rotator cuff tear arthropathy and avascular necrosis. Typically, shoulder replacement surgery is used to relieve the patient's pain. Patients whose arthritis is grinding bone-on-bone and have intact rotator cuff tendons make the best candidates for conventional, total shoulder replacement. In some cases, even after surgery, patients may still be unable to raise their arms higher than 90 degrees.
Replacement Surgery
Replacement surgery can involve either part of the joint (being a hemiarthroplasty) or both the ball-and-socket portions (being total shoulder replacement), depending on the extent of damage. However, the total replacement is the more common procedure. The replacement parts include a metal ball and a plastic, cup-shaped socket. The ball is on the end of a rod which is inserted into the upper arm bone. Depending on the condition of the surrounding bone, the surgeon may opt to use a press-fitted humeral component. Otherwise, he would use a cemented component. But with most new prostheses, the stem material is designed to encourage natural bone growth into the material. In most situations, the surgeon implants an all-plastic glenoid component--unless the glenoid's cartilage is in good condition, or the patient has a severely deficient glenoid bone, or the rotator cuff tendon's are torn and cannot be repaired. Ball-and-socket components today are designed to custom fit a patient's anatomy. During surgery, the surgeon must separate the deltoid and pectoral muscles in a relatively nerve-free area. The rotator cuff must be opened to allow the surgeon access to the ball-and-socket area. The surgeon removes any arthritic sections, puts in the new components, then closes up the area, stitching and cleaning the incision.
Reverse Total Shoulder Replacement
This technique has been used in Europe for years, but was only approved for use in the U.S. in 2004. It benefits patients with torn rotator cuffs and those who suffer from severe arthritis or have had a failed shoulder replacement in the past. This type of surgery may also help those patients previously unable to raise their arms beyond 90 degrees. Reverse replacement reverses the ball-and-socket mechanism. Instead of attaching the ball to the end of the arm, the ball is attached at the shoulder bone and the socket is placed at the end of the upper arm. This changes which muscles are doing the work in raising the arm, allowing the patient to use his deltoid muscle instead of a torn rotator cuff.
Tags: rotator cuff, shoulder replacement, raise their, raise their arms, replacement surgery used, shoulder replacement