SHAUN STANLEY/Durango Herald
It sounds corny, but the time-worn aphorism “two heads are better than one” sums up the advantages of the implant he uses in hip surgery, says Dr. Gary Scott, a surgeon at Durango Orthopedic Associates.
Scott, who has performed 40 to 50 total hip replacements a year for 30 years, is the only orthopedic surgeon in the Four Corners to use the ADMX3 insert.
Instead of the simple ball-and-socket solution, which provides one swivel point, the ADMX3 swivels at two points, giving the implant recipient greater mobility.
In a traditional hip replacement, extraneous material is removed from the socket in the pelvis and a metal shell and a liner are inserted. A steel ball on the tip of a rod driven into the top of the femur (the upper leg bone) mates with the cup, returning natural movement to the leg.
The dual-mobility prosthesis that Scott uses goes one step further.
The shell inserted into the pelvis socket receives two cups, one nestled inside the other, with the ball on the femur fitting into the smaller cup. As the leg moves, each cup swivels, the larger cup in the socket and the smaller cup within the larger cup.
Scott received his medical degree from the University of Nebraska and did his residency at the University of Kansas medical school. Scott, who has been in Durango since 1984, does knee and shoulder surgeries also.
Hip replacements are done to relieve arthritis pain that comes from years of wear and tear, disease, tumors or trauma such as an accident. About 250,000 hip replacements are done in the United States annually.
By way of comparison, an Associated Press story last week reported that in 2009, more than 600,000 knee replacements were done nationwide. About 4 million Americans older than 50 have artificial knees, the story said.
Scott said the average age of new-hip recipients is 70 years. A 26-year-old man was the youngest patient he has treated.
Hip surgery has made great strides since the first recorded replacement was made in the late 19th century. Dr. Austin Moore, an American surgeon, did the first metallic hip replacement in 1940 at Johns Hopkins Hospital in Baltimore.
Scott refers to Sir John Charnley, a British surgeon, as the father of modern hip surgery. Charnley’s joint design replaced others by 1970.
The dual-mobility prosthesis was developed by Dr. Gilles Bousquet, a surgeon at University Hospital at St. Etienne, France, in 1976. Although it was used extensively in Europe for years, the implant wasn’t authorized for use in the United States until 2007.
The first recipient reportedly was Johnny Bench, the retired Cincinnati Reds Hall of Fame catcher.
Different materials – ivory, Teflon, ceramics, polyethylene, a cobalt-chrome alloy and stainless steel – have been used through the years for femoral heads, pelvic cups and liners.
Designs change with attempts to find the best combination of materials, size and shape for the implants.
Large femoral heads provide more stability but wear faster. Small heads wear better but provide less stability.
Pagosa Springs resident Ellen Charnley, who has no relation to the English surgeon, is pleased with the new hip implant Scott gave her in June 2011.
“I had put up with a lot of pain in my right hip for more than a year,” Charnley said last week. “I was in pain when I climbed stairs, walked or sat in an automobile for any length of time. It affected my quality of life.”
Medications, muscle relaxants, physical therapy and a chiropractor brought no relief.
Charnley, 59, who was a certified nurse’s aide for 17 years, consulted Scott in April 2011 and had surgery a month later.
“I was very surprised and pleased by my recovery,” Charnley said. “I had two weeks of physical therapy following my operation and was walking a mile a day.
“I was back to church in two weeks with my walker,” she said.
Today, she moves well, keeping house, walking for exercise and chasing six grandchildren, Charnley said.
“If Dr. Scott told me I needed to have my left hip replaced I wouldn’t hesitate,” Charnley said.
Scott said the challenge is to duplicate the mechanics, durability, stability and longevity of the original hip.
The life expectancy of an implant depends on the use it gets – just like a new car, Scott said. If the buyer follows scheduled maintenance, changes the oil on time and drives sensibly, it will last a long time.
The average 40-year-old adult takes about 1 million steps a year.