Total Joint Replacement Surgery
By Dr. Stephen Lucie
Total Joint Replacement Surgery
Millions of Americans suffer from arthritis of the hip and knee. Most can be successfully treated
conservatively with rest, heat, ice, and anti-inflammatory medications. At some point the pain and loss of
mobility begins to affect the lifestyle of the patient and even his ability to work. Sometimes small
procedures such as arthroscopy or arthroscopic cartilage transplantation procedures can help, but
usually with advanced arthritis, joint replacement becomes the best option to eliminate severe pain and
restore patients to their usual lifestyle.
To watch a video about total knee replacement, please click Video.
Total joint replacements were introduced in the United States in the 1970’s. The total hip and the total
knee have been the most frequently performed joint replacements; although, total shoulders, total
elbows and ankle replacements are successful and are being done around the country. The total hip
replacement may be one of the best operations in the past century, and can actually restore a patient’s
function to a level that they forget that they even have a joint replacement.
These are not small operations and usually require 3-5 days of hospitalization plus up to 1-2 weeks of
Inpatient rehabilitation before the patient is able to return home. As the operations proved very
successful, they began being done in younger and younger individuals who are more and more active
and this caused the joint replacements to wear out or become loose. Many recent advances in joint
replacement design have addressed these issues.
In the past 5 years, total hip replacement has undergone a number of design innovations beginning with
the introduction of highly crosslinked polyethylene in the socket. One of the biggest problems with total
hip replacement was wear of the plastic socket. The wear particles from the plastic caused loosening of
the entire joint replacement. Newer plastics offer the promise of much less wear and longer life. Metalon-metal hip replacements, where the ball is metal and the socket is metal, have been around since the
1970’s, however, they fell out of favor until recently. They were reintroduced in Europe and then in the
past 5 years in the United States.
Metal-on-metal implants in total hip replacement have been introduced with the goal of reducing wear
particles and increasing the life of the total hip replacement. There have been some concerns that metal
particle levels in the blood stream were elevated in patients with metal-on-metal prostheses. This has not
been a problem to date, but caution should be used in patients who have preexisting kidney disease and
in women ofchildbearing ages because of elevation of the cobalt and chromium particles circulating to the baby.
Within the past 2 years, ceramic implants have been released in the United States. These too have been
around for a number of years and have been taken off the market at times for breaking and failure.
However, the newer designs are constructed
with aluminumoxide ceramic, which promises lower incidence of breakage and wear. Early reports of
these ceramic -on-ceramic devices show extremely low wear rates and minimal particle release from
wear. These implants have been used in Europe more than 25 years, but the FDA approval did not
come in this country until 2003. These implants look very promising for young people. Anyone with a
job that requires jumping and impact should tread cautiously until we are sure the breakage will not be a
Total knees, which were introduced in this country in the late 1970’s, have undergone a slow but steady
design improvement and newer designs offer more normal flexion and improved wear rates. Many of
today’s designs can be expected to last 15 to 20 years.
Some of the newer designs such as the DePuy rotating platform offer rotational motion as well as
flexion and extension to reduce wear, and designs by Zimmer and some of the other companies have
improved flexion to a degree that approach that of the normal knee.
Many patients’ knees began to wear only on the inside half of the knee with the outside portion and the
knee cap portion of the knee remaining good. In 2001, the Unispacer device was introduced to the
United States as a minimum incision procedure where a metal spacer is inserted after an arthroscopy of
the knee through a very small incision for treatment of wear of the medial compartment. For the patients
who do not desire a
complete total knee replacement and only have wear in the inside portion of the knee, this offers a very
attractive surgical option. This can be done in patients regardless of their weight and patients can be up
walking, full weight bearing on these spacer devices immediately and back to their usual lifestyle in
three months. Due to the interest in the Unispacer device and its subsequent direct-to-patient
marketing, patients have flocked to physicians in search of easier alternatives to the full joint
Unicompartment knee replacement is the next step above the Unispacer for those patients who are not
over 200 pounds and have arthritis confined only to the inside of the knee. The Unicompartment knee
replacement is a slightly larger procedure than the Unispacer but in many cases they offer improved
function and less pain, particularly in those whose arthritis may be too advanced for a Unispacer
Minimal incision surgery (M.I.S.) with total hips and total knees offer the patients the same small
incision that one gets with the partial joint replacement and an earlier return to function and in many
cases allows the rehab to progress quicker with less pain. In a total knee replacement, these small
incisions are designed not to violate
the quadriceps muscle, which is the muscle on the front part of the thigh that controls the extension of
the knee. By not cutting into this muscle, the patient’s rehab goes much faster. They are able to weight
bear with less pain with an early return to walking. Minimum incision total hip replacement is still in its
infancy but early reports are encouraging. Minimal incision total hips may lead to less scarring, smaller
incisions, less blood loss and earlier rehabilitation than traditional total hip replacement. Both total hips
and total knees demand precision in the implementation and not all patients are candidates for this type
of surgery. Those who are overweight or have severe deformities of either the hip or knee are not
candidates for minimal incision type surgery.
Direct-to-consumer marketing of orthopaedic implants has begun. The public is getting used to Viagra
race cars and multiple advertisements in their favorite magazines for blood pressure and arthritis drugs.
We are now seeing famous, aging golfers pitching certain types of total hip replacements. For patient’s
seeking advice on joint replacement, their best source of information is to sit down with their
Orthopaedic surgeon and go over all these new options and decide which is right for them. The choice
of which, if any, of these new technologies is best left in the hands of an experienced Orthopaedic
surgeon knowledgeable in joint replacement. He has had years of training and experience and knows
what works best for him in a particular situation and that source of information is far superior to that
found on the Internet, TV, or printed advertisements.