Hip replacement: New approach to an old procedure

Just hours after Dr. Dick Wallin had his right hip replaced, he stood up. The next day, he used a walker to "cruise around the nurses' station" at St. Mark's Hospital, and shortly after that he learned to use crutches on a stair exercise machine.

When he went home on day three, he needed only one crutch, which he discarded a week later. Within a couple of weeks, he was walking down his long driveway to retrieve the newspaper and the mail. He was also driving again.

"I was all set up for living in a restricted fashion, but by the time I went home in three days, I could go upstairs to my bedroom. It has been a surprisingly good experience," said Wallin of a new approach to hip-replacement surgery that's said to spare muscle and ligaments, seems to reduce the risk of dislocation, produces less pain and shortens recovery time.

The key to a "direct anterior approach" total hip replacement is the positioning of the patient during surgery and the location of the incision itself, according to Dr. E. Marc Mariani, a board certified orthopedic surgeon at St. Mark's Hospital who with colleague Dr. Michael H. Bourne and Dr. Peter Novak of the Salt Lake Orthopaedic Center are the first three Utah surgeons using the technique — something they predict will soon change.

According to the American Academy of Orthopaedic Surgeons, approximately 375,000 Americans undergo hip replacement surgery in hospitals around the country every year. They estimate the number will increase to 572,000 by 2030.

For most hip replacement surgeries, the patient lies on his side, supported by bolsters, and the surgeon cuts along the side of the hip or along the posterior. Those approaches are tried and true, says Mariani, but like all approaches, there are pros and cons. For instance, when the incision is made posteriorly, more care must be taken to avoid dislocating the new hip afterward. And while most surgeons favor making the incision on the side, muscles and ligaments are cut, so recovery takes longer.

With the direct anterior approach, the patient lies on her back on a specially designed operating table and a smaller incision is made in the front of the hip, near the groin. Muscles and ligaments are moved out of the way instead of detached and the hip is manipulated under fluoroscope X-ray to make sure the positioning is right. Bourne said it also allows more precise adjustment of leg length and that lying supine is safer from an anesthesia point of view because it provides a better airway.

Sometimes when muscle is traumatized, bone forms in it. Not detaching the muscle greatly reduces that possibility.