Joint venture Surgeons develop better way to install artificial

Tuesday, September 18, 2001

WASHINGTON -- Just 12 hours after getting an artificial hip, Sally Heinzen was out of the hospital and back home. That's astoundingly fast -- most hip implant recipients are hospitalized four or five days.

A Chicago doctor, teamed with surgeons in Oregon and Canada, is turning the grueling job of hip replacement into a minimally invasive operation by slipping in the artificial joint through two small incisions instead of a 12-inch slice.

It's the same metal or plastic artificial hip surgeons have used for years. What's new are saws, drills and other equipment reinvented to work in small spaces so surgeons no longer must dislocate and wrench out patients' old hips before slipping in the new one.

25 cases so far

Dr. Richard Berger has performed the easier implant on 25 patients at Chicago's Rush-Presbyterian-St. Luke's Medical Center, and his colleagues have operated on a handful more in Montreal and Portland, Ore.

Aided by hip manufacturer Zimmer Inc., the team is performing a 120-patient study to ensure the new technique eases short-term recovery without harming the new joint's long-term usefulness. Berger plans to report at a meeting of hip surgeons next month that so far, patients are doing very well, with less pain, less muscle damage, less bleeding.

How happy are patients? Consider Heinzen. At 43, the Kenosha, Wis., X-ray technician always limped despite using strong painkillers, because a fall from a horse had destroyed her hip's cartilage. But she couldn't take off the three months her doctor advised to recuperate from traditional hip replacement.

Four weeks ago, Berger operated. Heinzen traded crutches for a cane in about two weeks, and is about to return to work.

"I was going up the steps every day before I would have even been out of the hospital under the standard way of doing it," Heinzen said.

Much less invasive

Around 250,000 hip replacements are performed each year, a number growing as the population ages. Artificial hips can bring tremendous relief to people virtually crippled by hip pain, but many avoid having one implanted because recovery from the operation can take months.

Traditionally, surgeons make a 12-inch incision on the hip's side. They pull on the leg until the hip dislocates and they can cut off the femoral head, the ball-shaped bone that makes the joint move. They scrape off the bad cartilage, insert an artificial ball-and-socket, and then slide a 6-inch rod inside the femur, or thigh bone. The rod and ball attach to form the new joint. Surgeons either cement the rod into place or, often, let the patient's own bone grow into the rod over a few months.

With the new procedure, patients lie on their backs. Surgeons make two incisions, each 1 1/2 inches long, around the top and bottom of the pelvis. Through the first incision, they push two muscles aside instead of slicing them and bring the hip's ball into view.

"We used to have to pull and stretch and do all this stuff to the leg to dislocate the hip" and then slice off that femoral head, Berger explains. Now he inserts a special tiny saw, cuts the femoral head and takes it out in pieces, and slips in the artificial ball-and-socket.

Next, Berger crosses the patient's legs, providing direct access to the thigh bone through the second incision. Slide in the rod, connect it to the ball, and the operation's done.

Still needs study

It's an intriguing method but will take years of study to ensure patients do as well long-term as they do with regular hip replacements, warns Dr. John Callaghan of the University of Iowa, president of the American Association of Hip and Knee Surgeons. Plus, so far it is limited to thinner patients, because small incisions may not penetrate layers of fat, and those without huge hip deformities.

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