Minimally Invasive Surgery: Hype or Hip?
By Thomas Blumenfeld, M.D.
You may have seen the recent reports concerning the use of minimally invasive
surgery for hip and knee replacement surgery. You may be reflecting on
our average five day hospital stay, knowing that a patient was recently
discharged half day after a hip replacement using this technique. You
may be asking, why doesn’t my surgeon do this? in this article, I
would like to clarify the differences between a minimally invasive surgery
and a minimal incision surgery.
Why do you need an incision? The reason to make an incision is to allow
access to the operating areas in the pelvis and femur, or the knee, to
allow the surgeon to evaluate the bony anatomy, and appropriately place
the components in the hip. The incision must be large enough to allow
visualization of the contour of the bony actebulum, to be sure that all
soft tissue is removed that might inhibit bone ingrowth, and allow proper
orientation of the component. If the bone is soft, the incision must allow
room to place a drill in the operating field, and then put screws in.
The incision must allow evaluation of the femur so that the surgeon can
place the femoral component in appropriate position, and remove the correct
amount of bone to allow cementless ingrowth and bony stability, or good
interdigitation of cement for a cemented stem. Finally, the incision must
allow the surgeon to evaluate the position of the components through a
range of motion, to be sure the hip is stable, or that the knee components
are aligned.
The size of the patient dramatically effects the size of the incision.
How long should the incision be? Imagine trying to get something out of
your purse. If the opening is small, you must feel for things, and cannot
see them well. If the opening is bigger, you can not only feel for them,
but see them as well. If the purse is deeper (or the patient is larger)
you need a larger opening to see the bottom. With a small incision, some
amount of visualization and feel must be sacrificed. The surgeon needs
to weigh out what he needs to see, what can just be felt and make the
appropriate length incision.
What is the difference between minimally invasive surgery and minimal
incision surgery? First of all, these are not synonymous. Minimally invasive
surgery means attempting to do the least dissection and hence the disruption
to the soft tissues, primarily the muscle and tendons, while allowing
the surgery to be performed. Minimal incision surgery means making the
incision small. One can make a small incision and still dramatically disrupt
the soft tissues, in fact working through too small an incision may lead
to more soft tissue disruption. Optimizing surgery would involve minimizing
the soft tissue dissection while making the smallest incision possible.
Minimal incision hip surgery is performed in one of two fashions. The
first, performed by Dr. Thomas Sculco of New York, uses a single incision
of 2 3/8 inches (6 centimeters). The second, developed by Dr. Richard
Berger of Chicago, utilizes two incisions of 1 3/16 – 1 5/8 inches
(3-4 centimeters). Given the length of these incisions, both are minimal
incision surgery. However the invasiveness is different for both procedures.
Dr. Sculvo’s procedure utilizes the same instrumentation as the routine
hip replacement, and by dissection and retraction of the underlying soft
tissues, performs the surgery. This method, we feel, is not optimal, as
the skin needs to be vigorously retracted to allow visualization of both
the acetabulum (socket) and femur (thigh bone). Dr. Sculvo’s surgery
at this time is minimal incision, without obvious change in the invasiveness.
Dr. Berger used fluoroscopy (an x-ray image) to guide placement of the
acetabular component into the socket through one of the incisions, and
the femoral component in to the femur through the other incision. This
guidance may allow less soft tissue to be dissected, and aid the surgeon
in appropriate placement of the implants. The downsides to this approach
are the use of radiation (the x-ray) and the need to become adept at looking
at a 2-dimensional image, and place components that sit in three dimensions.
If this is not done properly, it may lead to component malposition, leading
to dislocation or failure of the components to grow in to the bone, or
inadvertent damage to bone or soft tissues. This approach however is both
less invasive, and uses smaller incisions.
For knee replacement surgery, the use of minimal incision surgery is receiving
wide spread attention. Surgeons are touting their ability to perform a
knee replacement through a 3-inch incision (8 centimeters). The usual
incision is 6-8 inches (15-21 centimeters). For this surgery a form of
a knee replacement, the unicompartmental knee replacement, which replaces
only a portion of the knee joint, is utilized. Unicompartmental knee replacement,
prior to this application, was used by most surgeons for the following
indication: a patient 70 or older, lighter than 170-180 pounds, with arthritis
in just one half of the knee. In these select individuals (less than 10%
of all knee replacements performed in the United States) this technique
gave results similar to replacing the entire knee, with the benefits of
a more normal feeling knee, and perhaps quicker rehabilitation after surgery.
Because the components used for this surgery are smaller than those used
for a total knee, and will fit through a small incision, the application
of the unicompartmental knee replacement has been matched with the use
of a small incision to create a “new surgery”: Minimally invasive
knee replacement. This form of knee replacement is now being done in younger
patents. This “new surgery” should be considered experimental
with no real track record of results because until this time most surgeons
would not consider using a unicompartmental knee replacement in younger
patients, as prior results indicated a high likelihood of early failure.
This surgery relies on extending the indication for unicompartmental knee
replacement to younger patients, and to patients with the majority of
arthritis in one compartment and some arthritis in the other compartment.
It combines both a new technique and a smaller incision Time will tell
if this approach has merit.
Where do we see minimally invasive surgery headed? Minimally invasive
knee surgery will only come in to vogue if the longevity of the unicompartmental
knee replacement is proven. We will be carefully watching the early outcome
of this procedure. Minimally invasive hip surgery as greater promise,
for it combines the use of hip implants with proven longevity with minimization
of the incision. The approach of Dr. Berger seems reasonable, providing
the surgeon can learn to place the components in appropriate position
using an x-ray machine. We may be able to take this approach one step
farther, by integrating the use of the surgical robot, now being used
in the ROBODOC trial that some of you have participated in, with minimally
invasive surgery. This would involve having the robot prepare both the
socket and the femur, and placing the components in through the smaller
two incisions. The robot would insure proper placement of the components.
We are very interested in the minimally invasive revolution, and hope
that its promise will be realized. The expected benefits and possible
risks are summarized in the table above.
Further work will need to be done with this technique before it is safe
and efficacious. Many more cases and longer term follow up by multiple
surgeons is required before it will come to general use. Be assured that
we will begin using minimally invasive surgery as soon as we feel it is
safe. We may be participating in controlled studies to help us make that
determination. We hope that this discussion has allowed you to understand
some of what you are seeing in your paper or magazine. Please feel free
to discuss hip or knee replacement via minimally invasive surgery with
your surgeon.
We have a Gold Medallist Amongst Us
Congratulations to Wileen Platt who recently won two gold medals at the
recent California Senior Games. Wileen placed first in both the 50 yard
Free and 50 yard Back in the novice division for the 80-84 year age group.
She has been competing in the swimming events in the Sacramento-Northern
California Senior Games since 1993 with the exception of the past couple
of years when a painful hip prevented her entering the games. Following
her total hip replacement in July of 2000 she was abler to compete again
in June of 2001 and won her two most recent medals bringing to a total
of 16 GOLDS! Wileen and her husband also enjoy ballroom dancing twice
a week. WAY TO GO, WILEEN!
If any of you have similar experiences you would like to share, please
send the information to our office, attention: JOINT EFFORT.
Patient Follow-up: The Numbers Have Caught Up To Me!
By William L. Bargar, M.D.
One of the true joys of clinical practice and one of the main reasons
I went into Orthopaedics is the ability to follow the progress of all
my patients. I tell my patients they will be seen at least every two years
for the rest of their lives. This is a situation unique to our orthopedic
practice, since joint replacement surgery requires lifelong follow-up
care, and nearly all of our practice is dedicated to joint replacement.
A mathematical certainty, however, and my own limits of time have created
a situation, which I need to resolve.
I perform about 250 total hip and knee replacements each year, and I have
done so since my practice began in Sacramento over 20 years ago. The scheduled
post-op follow-up visits are at six weeks, three months, six months (for
revisions), one year and then every two years thereafter…forever!
Since about 30% of my cases are revisions, there are 825 follow-up visits
each year, just for the patients I operate on that year. Accounting for
the rechecks from the surgeries from the previous 20 years, there is an
additional potential of 2,500 patients to be seen. Add to this the 250
pre-op visits, an equal or greater number of new patient appointments,
the unscheduled post-op visits and you have nearly 4,000 office visits
per year!
In other words, it has become a physical impossibility for me to continue
to personally see all of my patients at each and every follow-up visit.
For this reason, beginning in January 2002, Brian Shontz, my Physician
Assistant, will begin seeing many of my patients for their scheduled follow-up
visits.
As many of you know, Brian has had two total hips himself, one just last
year. So, in some ways he knows the experience better than I do. He has
worked closely with me for over three years, assists me in almost every
case, and does rounds with me (and on his own) in the hospital. Brian
knows each case well, and knows the expected post-op course. I feel he
is the ideal person to extend my practice and allow me to fulfill my promise
of lifelong follow-up. Of course, I will continue to review the x-rays
and discuss each case with him. Brian is an extension of me, which means
he reviews each case with me and since he is my employee, the billings
reflect my charges and practice time.
I have every confidence that your level of care will be excellent with
Brian and myself working together to maintain the high standards you’ve
come to expect from the Joint Surgeons of Sacramento.
The Sulzer Hip Recall: One Year Later
It has been a year since Sulzer Medical announced the recall of the InterOPacetabular
component. Perhaps we now have some perspective and can gain some insight.
All of us are familiar with recalls of products by manufacturers. It seems
almost impossible to avoid occasional mistakes in the manufacturing process
of mass-produced goods. Most times there is no harm caused to the customer,
but the product simply fails to function as intended. The manufacturer
announces the recall and the customer may return the product for a free
repair or a refund. There are, of course, instances where customers are
injured or killed (e.g. tires and baby seat). In these instances, the
reason for the recall is to protect more customers from harm.
With surgically implanted medical devices, however, there exists a unique
situation. Replacing or repairing the device requires another surgery.
This is usually a necessity for patients whose implants have already failed,
but for the remainder of the patients this situation creates concern and
worry about the future need for a re-operation. It is in this context
that the recall of the Sulzer InterOPacetabular component occurred.
Let us review. Sulzer introduced the InterOP cup in 1997. It was patterned
after a previous design that had a proven ability for successful fixation
to bone, but this new implant had an improved locking mechanism of the
polyethylene and allowed the use of larger femoral heads with highly cross-linked
polyethylene to reduce wear and improve stability. Prior to this implant,
Sulzer (a Swiss company) had a long history as a successful and highly
reputable manufacturer of orthopaedic devices. In late 1999, Dr. Blumenfeld
and I began using this implant in our younger and more active patients
for the advantages mentioned above. By September of 2000, we and other
surgeons began to see cases of early loosening of the implant and notified
the company. An internal investigation began and on December 8, 1000 Sulzer
announced the worldwide recall of the device.
Sulzer told us that as a result of their investigation, they determined
that a manufacturing process change, made in mid-1999, appeared to allow
a residue of machine oil (“mineral oil”) to remain on some implants.
According to the company, this oil may cause an inflammatory reaction
early after implantation that can block the ingrowth of bone resulting
in mechanical loosening of the implant. Apparently not all implants manufactured
after this process change had the oil residue, but there seemed to be
varying amounts on some and to be safe, they recalled all implants manufactured
after the process change.
Sutter Hospital’s records allowed us to identify potentially affected
patients and we notified them as soon as we confirmed the list. This,
of course caused much worry and concern amongst all patients with total
hip implants. Our phones lines were flooded with patients wondering if
they were affected. Unless we notified you, you do not have one of the
affected devices.
Since 1995, the FDA says that there have been 39 recalls of hip replacement
components, but in two-thirds of the recalls, the parts were merely mislabeled,
and were not defective. Of the 13 recalls for manufacturing or design
flaws, the Sulzer case is by far the largest: 40,000 components of which
26,000 had been implanted. Between Dr. Blumenfeld and myself we have 42
patients that received recalled implants, the majority of which are doing
well with no evidence for loosening. We have had to re-operate 12 patients
for loosening. Almost all were within one year of their original surgery.
We are following a few more patients who have some signs of possible loosening,
but we do not anticipate the number to increase. It appears that the effect
of the mineral oil occurs early after surgery, and unless it completely
blocks ingrowth, the implant can still be successful.
The company has made a commitment that patients affected by this recall
should not have any residual out-of-the-pocket medical expenses for additional
treatment. Any patients whom we have notified, that have affected implants
and have such residual medical expenses, should contact Sulzer directly
via their patient hotline: 800-888-4676, ext. 232. Many affected patients
nationwide have chosen to seek legal redress for damages. A settlement
offer for injured parties is being reviewed in the courts.
Could this have been prevented? That is a question for the courts. It
was not a known problem prior to this case. What about the upside? Like
the Sept. 11 tragedy and the recent airline crashes, I believe we can
take this recall and the resulting injuries as a sign that we are vulnerable
and bad things can and do happen. We take so much for granted. We need
to cherish each day of good health and be thankful for all that goes right
in the world. The orthopaedic industry has now learned to be even more
vigilant in their quality control processes. Cleanliness standards for
all types of potential contaminants have been improved. The implants made
since the recall are better than they were. That certainly doesn’t
justify the mistake that led to the recall, but we can and have learned
positive lessons from this.
Please take a few moments to complete the following questionnaire. Return
this survey by folding it over, with the address reflected on the outside.
Thank you for your time.
Staff Updates: Welcome Mary Pat, Marisa & Christina!
Carla Karn worked as Dr. Blumenfeld’s medical assistant for the past
year and has chosen to return to school and work part-time. She is looking
to get an RN license and work in hospital trauma. Many of you have already
spoken to Mary Pat Flynn, RN who is working for Dr. Blumenfeld.
Mary Pat Flynn
Mary Pat was born in Chicago and moved to California with her parents,
older brother and sister when her dad took a job with Aerojet. She attended
St. Ignatius Grammar School. Loretto High School and then went to the
University of San Francisco to earn her RN and Bachelor of Science. Mary
Pat stayed in San Francisco to work at Presbyterian Hospital and later
moved to Portland, Oregon, for a couple of years to work at Good Samaritan
Hospital. Her travels finally brought her back to Sacramento where she
managed an internist’s practice for 15 years. During that time her
daughter, Jamie, was born. Jamie is now a UCD freshman, majoring in physics,
this week – next week, who knows! Mary Part began assisting part-time
last June in our office. We are so glad to have her helping us full time
as Dr. Blumenfeld’s nurse.
Marisa Ward
Marisa was born in Reno, Nevada and raised in Edmond, Oklahoma. She moved
to California in 1993 to be closer to friends and family. Marisa says,
“I now realize that it was one of the best decisions I’ve ever
made, as I absolutely love it here.” She is a part-time employee
and handles the billing and collections for both Drs. Bargar and Blumenfeld.
Marisa came here in December of 2000 and just had her one-year anniversary
in August; she married Robert Ward and after honeymooning in Puerta Vallerta,
started back to school at CSUS. Marisa is currently studying communications
and plans to graduate next spring.
Christina Byrd
Christina was born in Denver, Colorado and has lived in Sacramento for
21 years. She is married to James and has two beautiful children, James
and Emily. Christina has
worked in the medical field since 1997. She says that it is the best field
to work in since she loves working with people.
Farewell Party for Shannon
We were sad to say good-bye to Shannon. The office threw her a farewell
dinner at the end of January just before she left for Long Beach to be
closer to her mother and grandmother.
Airport Security Requires More Than Physician Notes
Please be advised that a note or card from a physician will not necessarily
speed up the move through security as a way of dealing with airport security
checks for patients with medical implants. If a security alarm sounds,
the Federal Aviation Administration requires a resolution: A handheld
screener is used, and, if needed the implant patient must consent to a
noninvasive body search in order to board the plane.
Hype or Hip?