Topics > Shoulder > Shoulder Replacement
Shoulder Replacement
Although less common than a knee or hip replacement, shoulder joint
replacement typically provides the same benefits of joint replacement
including reduction of pain and restoration of more normal joint movement.
For some, shoulder replacement provides a significant improvement in
their ability to participate in the activities of daily living comfortably.
With that said, however, deciding to replace the shoulder joint should
be a carefully considered decision weighing all the benefits, risks and
complications.
Two components make up the artificial shoulder joint. One
is the humeral component, which replaces the head of the upper arm bone.
It is made
of metal (usually cobalt/chromium-based alloys) and has a rounded ball
attached to a stem that fits into your bone. The second component,
the glenoid component, replaces the socket. This portion of the joint
is most commonly constructed from plastic. Either (a hemiarthroplasty,
humeral head replacement) or both of the components may by replaced
(total shoulder replacement). The components come in various sizes
and shapes and are held in place with either acrylic bone cement (cemented)
or bone ingrowth (cementless). As in the natural joint, the surrounding
muscles and tendons provide stability for the prosthesis.
The surgical
incision is 3" to 4" long and is made on the front
of the shoulder from the collarbone (clavicle) to the point where the
shoulder muscle (deltoid) attaches to the upper arm bone. Special attention
will be paid to all the structures that cross the shoulder, including
the vessels and nerves and the muscles will be carefully inspected to
look for injury.
The upper arm bone is dislocated from the socket to
expose the ball-like end of the upper arm. Only the portion of the bone
covered by articular
cartilage is removed. The cavity of the upper arm bone is cleaned and
enlarged to facilitate the insertion of the humeral component of the
replacement’s stem, with the proper size and shape particular to
the patient selected. The top end of the bone is smoothed so the stem
can be inserted flush with the bone surface.
Depending on the health
of the socket and the surrounding muscles the socket may or may not
be replaced. However, if the socket is beyond salvage,
the surgeon will implant the glenoid component. The damaged cartilage
is removed the new socket is contoured to overlie the existing socket.
Protrusions on the polyethylene component are then fitted into holes
drilled in the socket surface. Once a precise fit is achieved, the
component is cemented into position. The arm bone, with its new prosthetic
head,
is replaced in the socket. The surgeon reattaches the supporting tendons
and closes the incision. The arm is placed in a sling and a support
pillow is placed under the elbow to protect the repair. A drainage tube
is used
to remove excess fluids and is usually removed on the day after surgery.
Rehabilitation
after should joint replacement surgery usually begins the same day
as the surgery. Compliance with a rehabilitation
program
is vital to the success of the replacement. Initial physical therapy
will begin in the hospital with passive-assisted range of motion exercises
followed by the use of pulleys at home to bend and extend the arm.
There
are important do’s and don’t after shoulder joint
replacement once the patient returns home:
- Don’t overdo it! After
the first six weeks of surgery, the patient should not lift anything
heavier than a cup of coffee.
- Ask for assistance. Please inquire about services that are available,
such as home support.
- Wear the sling at night while
sleeping every night for at least one month after surgery.
- Do not use
your arm to push up from a chair or in bed.
- Carefully follow the prescribed
exercise plan, sometimes doing the exercises 5-6 a day.
- Don’t participate
in any sports activities or heavy lifting for at least six months.
Complications
after shoulder replacement surgery occur less frequently than with
other joint replacement surgeries. However, there are risks.
Infection, intraoperative fracture of the upper arm bone or postoperative
fractures, postoperative instability and loosening of the glenoid component
are the most common complications. Advances in surgical techniques
and prosthetic innovations are helping to reduce the occurrence of complications.
