A Patient's Guide to Artificial Joint Replacement of the Finger
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Introduction
If nonsurgical treatments are not successful in easing problems
of finger arthritis, your doctor may recommend replacing the
surfaces of the joint. Joint replacement surgery is called
joint arthroplasty.
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This guide will help you understand
what parts make up the finger joint
how the operation is performed
what to expect before and after surgery
Anatomy
What parts of the finger are involved?
The
finger joints work like hinges when the fingers bend and straighten.
The main knuckle joint is the metacarpophalangeal joint (MCP).
It is formed by the connection of the metacarpal bone in the palm
of the hand to the finger bone, or phalange. Each finger
has three phalanges, separated by two interphalangeal (IP) joints.
The one closest to the MCP (knuckle) is called the PIP, or proximal
IP joint. The joint near the end of the finger is called the
DIP, or distal IP joint.
Click to view bones of the finger.
Ligaments are tough bands of tissue that connect bones together.
Several ligaments hold each finger joint together. These ligaments
join to form the joint capsule of the finger joint. The joint
capsule is a watertight sack around the joint. The joint surfaces
are covered with a material called articular cartilage. This
material is the slick, spongy material that allows one side of a
joint to slide against the other joint surface easily. When this
material wears out, the joint develops a type of arthritis called
osteoarthritis and becomes painful.
Click to view a cross section of
a joint capsule, with articular cartilage.
Rationale
What does the doctor hope to achieve with surgery?
Arthritic joint surfaces can be a source of stiffness, pain, and
swelling. The artificial joint is used to replace the damaged joint
surfaces so patients can do their activities with freedom of movement
and less pain.
Pre-Intervention Instructions
What should I do to prepare for surgery?
The decision to proceed with surgery must be made jointly by you
and your doctor. You need to understand as much about the procedure
as possible. If you have concerns or questions, you should talk
to your doctor.
Once you decide on surgery, you need to take several steps. Your
surgeon may suggest a complete physical examination by your regular
doctor. This exam helps ensure that you are in the best possible
condition to undergo the operation.
On the day of your surgery, you will probably be admitted to the
hospital early in the morning. You shouldn't eat or drink anything
after midnight the night before. The length of time you spend in
the hospital depends a lot on your recovery from anesthesia after
surgery. In general, finger joint surgery can be done on an outpatient
basis, meaning you can leave the hospital the same day.
Procedure
What happens during the operation?
Doctors use silicone plastic implants to replace the original joint
surfaces. The artificial joint functions the same way a hinge on
a door does.
Click to view arthritic hand along
with joint implants.
The procedure takes about two hours to complete. Surgery may be
done using a general anesthetic, which puts you completely to sleep,
or a local anesthetic, which numbs only the hand. With a local anesthetic
you may be awake during the surgery, but you won't be able to see
the surgery.
Once you have anesthesia, your surgeon will make sure the skin
of your hand is free of infection by cleaning the skin with a germ
killing solution.
An incision is made across the back of the finger joints that are
to be replaced. The soft tissues are spread apart with a retractor.
Special care is taken not to damage the nearby nerve that passes
by the joint. The joint is exposed. The ends of the bones that form
the finger joint surfaces are taken off, forming flat surfaces.
Click to view shaping of the bone
ends.
View animation of the bone
ends being extracted.
A burr (a small cutting tool) is used to make a canal into the
bones that form the finger joint.
Click to view canal formed into
the bone.
View animation of canals being
created in the bone ends.
The doctor then sizes the stem of the prosthesis to ensure a snug
fit into the hollow bone marrow space of the bone. The prosthesis
is inserted into the ends of both finger bones.
Click to view implants inserted.
View animaton of the stems
being sized to fit the prosthesis snugly.
View animation of the prosthesis
being inserted into the bone ends.
When the new joint is in place, the surgeon wraps the joint with
a strip of nearby ligament to form a tight sack. This gives the
new implant some added protection and stability.
The soft tissues are sewn together, and the finger is splinted
and bandaged.
Complications
What might go wrong?
Infection
Any operation carries a small risk of infection. Replacing the
finger joint with an artificial joint is no different. You will
probably be given antibiotics before the operation to reduce the
risk of infection.
If an infection occurs you will most likely need antibiotics to
cure it. You may need additional operations to drain the infection
if it involves the area around either implant. In these cases, the
artificial joint will need to be removed. The surgeon will most
likely fuse the joint rather than attempt another artificial joint
replacement.
Nerve Damage
All of the nerves and blood vessels that go to the finger travel
across, or near, the finger joint. Since the operation is performed
so close to these important structures, it is possible to injure
either the nerves or the blood vessels during surgery. The result
may be temporary if the nerves have been stretched by retractors
holding them out of the way. It is uncommon to have permanent injury
to either the nerves or the blood vessels, but it is possible.
Prosthesis Failure
One of the problems that occurs with artificial replacements is
that they can fail. The older silicon-type prosthesis has been shown
to break apart and fragment. Most types of prostheses can displace,
or move out of the correct position, causing problems. Most of these
problems will require a second operation to remove and replace the
prosthesis.
Post-Intervention Instructions
What happens immediately after surgery?
After surgery, your finger will be bandaged with a well-padded
dressing and a splint for support. The splint will keep the finger
in a straightened position during healing. Your surgeon will want
to check your hand in five to seven days. Stitches will be removed
after ten to fourteen days, though most of your stitches will be
absorbed into your body. You may have some discomfort after surgery.
You will be given pain medicine to control the discomfort you have.
You should keep your hand elevated above the level of your heart
for several days to avoid swelling and throbbing. Keep it propped
up on a stack of pillows when sleeping or sitting up.
Rehabilitation
What should I expect during my rehabilitation period?
Patients wear an arm-length cast with the finger in a straightened
position for about three weeks after the prosthesis is implanted.
A physical or occupational therapist will direct your recovery
program. Recovery takes up to three months after a prosthesis is
implanted.
The first few therapy treatments will focus on controlling the
pain and swelling from surgery. Heat treatments may be used. Your
therapist may also use gentle massage and other hands-on treatments
to ease muscle spasm and pain.
Then you'll begin gentle range of motion exercise. Strengthening
exercises are used to give added stability around the finger joint.
You'll learn ways to grip and support items in order to do your
tasks safely and with the least amount of stress on your new finger
joint. As with any surgery, you need to avoid doing too much, too
quickly.
Some of the exercises you'll do are designed to get your hand and
fingers working in ways that are similar to your work tasks and
daily activities. Your therapist will help you find ways to do your
tasks that don't put too much stress on your finger joint. Before
your therapy sessions end, your therapist will teach you a number
of ways to avoid future problems.
The therapist's goal is to help patients keep their pain under
control, improve strength and range of motion, and regain fine motor
abilities with the hand and fingers. When patients are well underway,
regular visits to the therapist's office will end. The therapist
will continue to be a resource, but patients will be in charge of
doing their exercises as part of an ongoing home program.
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