Physicians Debate the Benefits of Minimally Invasive Surgery on Hips and Knees

SAN FRANCISCO -- Arthritis and other disabling

diseases have caused tremendous human suffering since the dawn of

civilization, but not until the 1960s did physicians find a good way to

replace diseased and injured joints with new ones. While replacement

components have undergone generations of improvements since then, the

operations themselves have changed little until lately, as minimally invasive

procedures have been introduced. Four orthopaedic surgeons share their

experiences and debate these issues at a panel briefing of the American

Academy of Orthopaedic Surgeons' 71st annual meeting this week.

Hip replacement

When less is more

Approximately 300,000 hip replacements are performed annually in the

United States alone, according to Thomas P. Sculco, MD, surgeon-in-chief at the

Hospital for Special Surgery, and professor of orthopaedic surgery at the Weill

Medical College of Cornell University in New York. Sculco began performing minimally invasive surgeries (MIS) for total hip replacements in 1996 as a response to

his patients' expressed displeasure with the cosmetic appearance of the

standard procedure, as well as their desire for a more rapid recovery, a

reduced length of stay, and a reduction in cost.

Minimally invasive procedures, using a 6 to 10 cm. incision, have become routine for 95 percent of his patients, Sculco says. With the right patient, these techniques result in less soft tissue trauma and less time in surgery. In Sculco's experience, MIS decreases the blood loss and allows patients an earlier return to a normal gait without an increased risk

for complications.

"I have used this less invasive technique in more than 1,500 patients. My

observation is that these patients recover more quickly and lose their limp

and need for a cane more quickly than with the standard approach," he says.

"There has been no increase in complications in my experience with this

approach in terms of wound problems, dislocation of the implant, or inferior

results when evaluated by X-rays."

Outpatient hips, anyone?

In the past, in-patient hospitalization following standard total hip

replacement frequently exceeded several weeks. During the 1990s, however, MIS

techniques such as those designed by Sculco reduced the length of stay to a

few days. Even more recently, Richard A. Berger, MD, assistant professor of

orthopaedic surgery at Rush-Presbyterian-St. Luke's Medical Center, developed

and implemented comprehensive protocols for before, during, and after surgery

to assess the feasibility and safety of total hip replacement on an outpatient basis.

"With MIS, outpatient surgery is feasible," he says. "We have shown in

the past three years that it is also safe. Every patient of ours who has had

surgery in 2003 has gone home the same day!"

Discharge is permitted only when strict criteria are met, Berger explains.

In addition to exhibiting stable vital signs, the patient must be able to get

in and out of both a bed and a chair independently, walk 100 feet, and ascend

and descend a full flight of stairs. Further, the patient must be able to

tolerate a regular diet and have adequate pain control from oral analgesics.

Berger says his patients are walking down the hall four or five hours after

surgery and they feel great. "They say, 'You're right. I feel good. I can

get around.' I say to them, if you want to stay in the hospital you can, but

they look me right in the eye and say, 'I want to go home.'

"Patients were afraid to go home in the past," Berger says.

"Specifically, they feared uncontrollable pain, developing a complication,

having a slower recovery, and being dependent on someone else. Once these

fears were dispelled, it made all the difference."

The first surgeon in the world to offer MIS in an outpatient package,

Berger currently uses minimally invasive approaches for almost all of his

patients, who are making a speedy recovery. On average, they discontinue

crutches and drive within six days, return to work in eight days, and walk

without a cane in nine days. They resume activities of daily living within 10

days, and those who wish can walk a half mile within 16 days! This is an

order of magnitude faster than has ever been done in hip replacement," Berger

says.

Knee replacement

A skeptic's point of view

More than 325,000 knees are replaced each year in the United States, and

that number is growing dramatically. Hundreds of thousands of people each

year, therefore, will be looking to identify the best knee replacement

procedures for this surgery. David S. Hungerford, MD, professor in the department

of orthopedic surgery at Johns Hopkins School of Medicine, believes there is

no convincing evidence that the patient will benefit in any meaningful way

from minimally invasive total knee replacements.

Hungerford says he reviewed 275 revision standard total knee replacements

performed at Johns Hospital Medical Center between 1987 and 1997 and came away

a skeptic.

"During this 10-year period, the surgeons involved in the study performed

approximately 3,000 total knee replacements of which about 275 were re-

operations," he says. "Although a few of the re-operations were cases that

were done by the study surgeons, originally, the vast majority were ones that

were performed by surgeons all over the country. "

From reviewing the pre-operative X-rays of these 275 knees, Hungerford

determined that 75 percent had technical failures; i.e., they were malaligned.

"If the surgeon, with full exposure, cannot reproducibly and reliably

align the knee, what will the outcome be with limited exposure? If MIS

becomes widespread in total knee replacement, there will be a significant and

predictable increase in the number of technical failures," he predicts.

Hungerford suggests that patients be wary of so-called revolutionary

advances. "Ask the surgeon how many cases he has done using this new

technique," he says.

"I have similar reservations for the hip, but not to the same extent as

for the knee. The whole issue of incision size is being blown out of

proportion. It is not something that should be touted as the next best

'latest and greatest' until it is proven to be so. "I would not even consider

it," he says.

Long-term gains fuel surgeon's efforts

Like Hungerford, Peter M. Bonutti, MD, FACS, of St. Anthony's Memorial

Hospital in Effingham, Ill. bases his opinions about minimally invasive knee

replacements on personal experience. In contrast to Hungerford, however,

Bonutti's experiences have been positive with an evolutionary approach.

Bonutti agrees that minimally invasive knee surgeries definitely are more

difficult procedures to perform and says surgeons should move ahead slowly or

risk significant complications. With the experience of more than 500 such

surgeries behind him since 1999, however, he has been able to do these

surgeries successfully with incisions as small as 6 cm.

A major feature of MIS, he points out, is to avoid everting the patella and dislocating the tibio-femoral joint and reducing damage to the

quad mechanism.

While Bonutti is pleased to improve the short-term benefits of knee

surgery, improving the long-term benefits is his passion. "Unlike total hip

replacements, which patients are extremely happy with, total knee replacement

patients always have a disability. "There is permanent functional

deterioration because the muscles have been cut." Standard surgery

traumatizes the muscle so much that patients cannot walk down a slope or kneel

down to pick something up. "These are activities of daily living," he says.

"In my opinion, this is what minimally invasive surgery on knees is all

about."

After four years, Bonutti's patients continue to do well in the long term.

They do well in the short term, too. While his discharge criteria are very

strict, he confesses, his patients are going home independently within three

days after surgery, as opposed to five days. And they are walking

independently with a cane and even driving within about 12 days -- compared

with 8 to 12 weeks with standard surgery.

"The driving force for me is my patients," says Bonutti. "I want to help

them get back to their lifestyle more quickly and with better functional

results. This is what medicine is all about."

The debate on surgical technique is not over. Orthopaedic surgeons review

each patient's case individually and the decision about optimum surgical

technique is always made after weighing many factors, including the surgeon's

advice, as well as patient input.

The 27,156-member American Academy of Orthopaedic Surgeons is a not-for-profit organization that provides education programs for orthopaedic surgeons, allied health

professionals, and the public. The Academy's annual meeting is being held March

10-14, 2004, at the Moscone Center in San Francisco.

Source American Academy of Orthopaedic Surgeons