Minimally Invasive Surgery For Hip and Knee Replacement Improves Patient Experience

with Michael J. Anderson, M.D., Orthopaedic Surgeon, Columbia St. Mary’s

Posted: May 1, 2005

Columbia St. Mary’s took the lead two years ago in introducing minimally invasive total hip replacement surgery in southeastern Wisconsin. Orthopaedic surgeon Michael Anderson is among the few physicians in the state who are trained to perform this surgery, as well as minimally invasive total knee replacement surgery.

Proven advantages
People who have minimally invasive hip replacement surgery at Columbia St. Mary’s have fewer complications, less pain, shorter hospital stays and lower hospital charges than people who have traditional hip replacement surgery.

Michael J. Anderson, M.D., Orthopaedic Surgeon, Columbia St. Mary’s "It used to take people about three months for full recovery. Now it takes about six weeks."

“In minimally invasive joint replacement surgery, the same artificial hip and knee devices are used as in traditional knee and hip replacement surgery,” Dr. Anderson said. “The minimally invasive procedure involves making smaller incisions and less muscular dissection.”

Columbia St. Mary’s has worked to refine this technique and the training of the surgeons and surgical team. The data show very good outcomes for the patients.

Advantages of the minimally invasive procedure include a lower infection rate, a smaller risk of implants popping apart after surgery, and a lower hospital readmission rate, Dr. Anderson noted.

“Muscle power returns faster with this type of surgery. Patients are usually taken off their walkers or crutches in about half the time as with an open surgical procedure. The time that a patient is going to limp is about half the time,” he added. “It used to take people about three months for full recovery. Now it takes about six weeks.”

What happens during the procedure?
The surgery involves using conventional prosthetic components (artificial hip parts) placed through a much smaller incision. However, it is not done with the aid of a laparoscope, which is a fiber optic tube working in conjunction with a TV monitor to provide a window into the interior of the human body.

“Because of this we’ve developed a different way to visualize surgery directly,” said Dr. Anderson. “It’s a matter of training our eyes differently to look down into a small incision. Our instruments are different too, working down and angled uniquely,” he explained.

“Since the incision is smaller, approximately 21/2 inches in length, we don’t dissect or open up a lot of muscle tissue around the hip. We try to leave as much of that muscle alone so it doesn’t hurt after surgery and the hip recovers its power sooner.”

The surgery involves removing the arthritic head of the femur and inserting a new, titanium mesh socket. “The socket resembles a small bowl, about 50 or 53 millimeters in diameter. It goes up into the pelvic area after we shape the socket. Then a conventional thigh piece, called a taper stem, which is usually made of titanium mesh, fits down into the femoral bone. It has a head on its top that fits into the socket. The prosthetic components are held in place by a tight grip between the titanium mesh and the bone (press-fit).”

This type of surgery is not recommended for every person in need of a hip replacement, cautioned Dr. Anderson. “Patients who are markedly overweight should not have this surgery, nor should people who have less than average bone quality. The quality of bones needs to be significantly better than average, since the implants are placed without bone cement on the thigh and socket pieces of the implant.”

Comparing minimally invasive and conventional surgeries:
Total hip replacement—Minimally invasive total hip replacement surgery uses a single incision of 21/2 to 3 inches, compared to 8 to 12 inches for conventional hip surgery. The smaller incision, usually placed over the outside of the hip, reduces the recovery time because the surgeon is doing less damage to the muscles, which regain their mobility and tone faster.

After a conventional hip replacement surgery, a patient typically uses crutches (or a walker) for six to eight weeks, and will regain full activity in three months. With minimally invasive surgery, patients can walk without crutches in four to six weeks and resume full activity within two months.

Data comparing 62 minimally invasive hip replacement procedures and 89 conventional (not minimally invasive) hip replacement procedures performed at Columbia St. Mary’s between November 1, 2002, through April 30, 2004, showed that the average hospital stay for patients who had conventional hip replacement surgery at Columbia St. Mary’s was 3.8 days, compared to 2.1 days for patients who had minimally invasive surgery. Complications following surgery were reduced by 60% for patients who had minimally invasive hip replacements. Columbia St. Mary’s costs and patient charges were nearly 11% lower for patients who had the minimally invasive procedure.

Total knee replacement—Minimally invasive total knee replacement surgery uses a single incision of 3 to 5 inches, compared to 10 inches for conventional knee surgery. The hospital stay is typically 36 to 48 hours, and recovery time is four to six weeks.

Most patients are candidates for minimally invasive hip and knee replacement surgery. For people who have advanced osteoporosis, a significant bone deformity, or who are very overweight, however, this technique would not be a good option.

Dr. Michael Anderson
(414) 223-2727
Blount Orthopaedic Clinic
625 E. St. Paul Avenue
Milwaukee, WI 53202

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