Joint Replacement - Shoulder Replacement

What is special about the shoulder joint?

The shoulder is a ball-and-socket joint that enables you to lift, twist and bend your arm. It also lets you move your arm forward, to the side and behind you. In a normal shoulder, the rounded end of the upper arm bone (head of the humerus) glides against the small dish-like socket (glenoid) in the shoulder blade (scapula). Both these joint surfaces are normally covered with smooth cartilage. They allow the shoulder to rotate through a greater range of motion than any other joint in the body. The shoulder joint sacrifices stability for an improved range of motion and the surrounding muscles and tendons provide support.

What is range of motion?

The shoulder allows for the rotation of the arm in all directions. The range of motion is dependent on the proper articulation of the humeral head upon the glenoid (shoulder socket).

Who needs shoulder replacement?

There are many conditions like those listed below that can lead to loss of the cartilage and mechanical deterioration of the shoulder joint. The result can be pain and a stiff shoulder that grinds or makes "clunks" on attempted movement. All this can lead to a weakness, decreased range of motion and poor function of the shoulder.
Radiologically there is erosion of the cartilage covering the joint surfaces and there can be irregularity or flattening in the contour of the bone. Frequently, loose pieces of bone and cartilage can be found floating inside the joint. In more severe cases, arthritis may lead to erosion (wearing away) of the bone.

Conditions frequently needing shoulder replacement are:
* Osteoarthritis (degenerative joint disease)
* Rheumatoid arthritis
* Post-injury arthritis
* Rotator cuff tear arthropathy (a combination of severe arthritis and a massive non-reparable rotator cuff tendon tear)
* Avascular necrosis (osteonecrosis)
* Failed previous shoulder replacement surgery

How do I prepare for shoulder replacement surgery?

If you and your surgeon decide that total shoulder replacement is right for you, a date will be scheduled for your surgery. Several things are necessary to prepare for surgery including a detailed physical examination and control of other problems such as diabetes or high blood pressure. Your surgeon or a staff member will advise you about the things you can do to prepare for your hospital stay, your surgery and your rehabilitation after surgery.

What happens during shoulder replacement surgery?

On the day of surgery an intravenous line will be inserted into your arm to administer necessary medications and fluids during surgery. You will then be taken to the operating room and given anesthesia. After the anesthesia takes effect, your shoulder will be scrubbed and sterilized with a special solution that removes bacteria from your skin.
The procedure is performed through an incision over the shoulder that will expose the joint. Special, precision guides and instruments will be used to cut the humeral head (ball) and prepare the bone to accept the implant. The new metal ball and stem are then inserted. If the socket is to be resurfaced, its damaged surface is smoothed and the new plastic surface is inserted. The ball and socket are then joined. When the surgeon is satisfied with the fit and function, the incision will be closed and covered with dressings. A special drain may be inserted into the wound to drain the fluids that naturally develop at the surgical site. The surgery usually takes one to three hours, although this depends on the severity of the arthritis in your shoulder.
A sterile bandage will be placed over the wound and you will be sent to the post-operative recovery room where you will be carefully monitored. After you regain consciousness you will be taken back to your hospital room.

What can I expect after surgery?

When you are back in your hospital room, you will begin a gentle rehabilitation programme to help relax the muscles around your new shoulder. On the day of surgery you may be encouraged to get out of bed and take a few steps. You will continue to receive pain medication as needed, and your bandage will be removed about two days after surgery. Hospitalization is necessary only for the first three to four days.

How soon can I return to normal activities after surgery?

Successful joint replacement surgery may relieve your pain and stiffness, and may allow you to resume some of your normal daily activities as instructed by your doctor. But even after you have fully recovered from your surgery, you may still have some restrictions. Normal daily activities for shoulder replacement patients do not include contact sports "jamming" activities such as hammering, repetitive heavy lifting, or activities that put excessive strain on your shoulder. Although your artificial joint can be replaced, a second implant is seldom as successful as the first.

How long will a shoulder replacement last?

Longevity of the prosthetic shoulder varies from patient to patient. It depends on many factors, such as a patient's physical condition and activity level, as well as the accuracy of implant placement during surgery. It is useful to keep in mind that prosthetic joints are not as strong or durable as a natural, healthy joint, and there is no guarantee that a prosthetic joint will last the rest of a patient's life.

Today, total shoulder replacement is becoming a common and predictable procedure. Many patients enjoy relief from pain and improved function, compared to their status before surgery. As a result, some patients may have unrealistic expectations about what the prosthetic shoulder can do and how much activity it can withstand. As with any mechanical joint, the ball and socket components move against each other. Natural fluid in the joint space, called synovial fluid, helps to lubricate the implants just as it lubricates the bones and cartilage in a natural joint. Still, the prosthetic components do wear as they roll and slide against each other during movement. As with car tires or brake pads, the rate of wear depends partly on how the shoulder joint is used. Activities that place a lot of stress on the joint implants, as may be the case with more active patients, may reduce the service life of the prosthesis. Implant loosening and wear on the plastic portions of the implant can lead to the necessity for revision surgery to replace the worn components, or all of the components. Your doctor will be in the best position to discuss these issues with you, taking into account your particular clinical circumstances, the type of implants used, and your post-surgical lifestyle.

Talk with your doctor about the following points, and how they might affect the longevity and success of your shoulder replacement:

* Avoiding repetitive heavy lifting
* Avoiding "jamming" activities such as hammering
* Staying healthy and active
* Avoiding "impact loading" sports such as boxing
* Consulting your surgeon before beginning any new sport or activity, to discuss what type and intensity of sport or activity is appropriate for you
* Thinking before you move
* Not lifting or pushing heavy objects