Better With Age
More durable implant makes for longer-lasting hip replacements
When Mark Contrestano of San Antonio started feeling pain in his left hip, he knew it might be something serious. He has been a senior sales representative for a large medical device company for 25 years and knows a thing or two about human anatomy.
Contrestano had a small harmless tumor (lipoma) midway down his anterior thigh that ached when he rode his recumbent bike. He attributed this pain to that lipoma after talking with his mother who had had one removed a few years back.
His 95-year-old mother would walk two to three miles daily and experienced pain in her right anterior thigh until she had her lipoma removed. After surgery, that area never bothered her again while walking.
One day last April, Contrestano, 54, was surprised when his hip began snapping while hitting a golf ball and subsequently started to come out of the socket, he says.
He went to see his orthopaedic surgeon. X-rays and magnetic resonance imaging (MRI) revealed that the pain he was feeling in his thigh was a referred pain from a labral tear (injured soft tissue of the hip) and not the lipoma.
The X-ray showed he was virtually bone-on-bone.
With years of golf ahead of him, Contrestano’s interest piqued when he heard about a long-lasting hip replacement being tested in Houston and other cities. “I just wanted to go through the procedure once. I wanted it done right and I didn’t want to have to ever redo it, if possible,” he says.
After researching and discussing options with his orthopaedic surgeon in San Antonio, it was recommended that Contrestano travel to Houston to meet with Stefan Kreuzer, MD. Within minutes of meeting Kreuzer, Contrestano knew this was the man and the procedure Contrestano would entrust to get him “back to par.”
The trial includes 10 clinical sites nationwide, with the Houston study being led by Kreuzer and Adam Freedhand, MD, both orthopaedic surgeons at The University of Texas Health Science Center at Houston (UTHealth) and the Memorial Hermann Memorial City Medical Center.
“Dr. Kreuzer thought I was an ideal candidate for this ceramic-on-ceramic hip replacement. He said it had been used in Australia for some time,” Contrestano recalls. “In addition, Dr. Kreuzer and Dr. Freedhand use a less invasive surgical approach that involves operating through the front of the leg (anterior) rather than the rear (posterior).”
Kreuzer, Freedhand and their colleagues are comparing a ceramic-on-ceramic bearing surface versus the more traditional ceramic-on-plastic bearing. It is a blind study, meaning patients do not know what bearing surface they have received until the study is closed. Two in three participants will get the ceramic-on-ceramic bearing.
In August 2013, Contrestano had the surgery done in Houston. While he isn’t sure which type of device he received, he is feeling great.
Routine — yet major — surgery
Each year in the United States, surgeons perform hundreds of thousands of total hip replacements. Without them, it would be painful for some people to walk or even just get out of a chair. With a stiff hip, it can be a strain just to put on your shoes and socks.
“Many of the patients are younger and more active and greatly benefit from a new and more durable implant,” Kreuzer says.
The hip is where the thigh bone (femur) and hip bone (pelvis) meet. The upper thigh bone is shaped like a ball, which fits into the socket of the pelvis. The ball-and-socket joints of the hips allow for pain-free motion between the torso and lower body.
Over the course of a lifetime, the smooth cartilage lining of the ball-and-socket joint can wear out and make movement painful. Other conditions, such as rheumatoid arthritis and trauma, can result in a painful arthritic hip.
Kreuzer says most people with mild to moderate arthritis can lead normal lives and benefit from non-operative management. Medications, physical therapy and lifestyle changes can relieve the symptoms of arthritis. However, as the arthritic condition worsens, some will require surgery.
Hip replacement surgery involves removing the arthritic head of the femur and the surface of the arthritic socket. The artificial hip consists of a titanium stem that goes into the upper thigh bone and a metal shell that fits in the socket. The new joint is mounted onto these parts and can be made of metal, ceramic or plastic. These devices can be attached to the bone with or without cement.
Though routine, hip replacement is still considered a major surgery that requires a brief hospital stay and a patient’s dedication to his or her recovery. “It is something most patients only want to do once,” Kreuzer says.
A longer lifespan
Advances in technology have produced bearing surfaces with much lower wear, which means a longer lifespan for the implants. Ceramic-on-ceramic implants show the lowest wear in the laboratory and some believe they could last 30 years or more. Historically, hip replacements have lasted 15 to 20 years.
The most common implants are composed of metal and plastic. The ball-and-socket is replaced with a metal prosthesis and a plastic spacer is placed in between. Metal-on-metal is another type of implant and there is no plastic spacer in between.
While ceramic-on-ceramic implants have been used in hip replacements for years, the new device differs in that the ceramic is harder than traditional ceramic and less brittle. Kreuzer adds that these ceramics are fracture resistant.
“If a tire sits in your garage for 30 years, it will rot. This is part of the aging process. The same can be said of plastics but ceramics are not known to age in a patient,” Kreuzer says.
The newer ceramic devices could be a boon for baby boomers who are living longer with their implants and for younger patients with arthritis problems who will be living with the implants for the duration of their lives.
Kreuzer says investigators have recruited a little over three-quarters of the 70 patients sought for the study’s Houston component.
“This device is approved and used in Australia and many European countries. But it has not been approved by the Food and Drug Administration here for use,” says Kreuzer, who helped design the nationwide study.
Kreuzer says one of the issues with traditional hip replacements is the wear and tear on the ball-and-socket, which can result in the accumulation of particles in the joint causing irritation, wear and failure of the hip replacement. “With the new ceramic-on-ceramic, the wear is negligible,” he says.
“If I were to need a hip replacement, this is the type I would get,” Kreuzer adds.
Back in the Alamo City, where Contrestano completed his post-operative physical therapy, he recently hit the golf course and shot an 85, which — for those who don’t play golf — is a great score.