New Artificial Ankles Offer Another Option To Bone Fusion
Now the nation is embarking on a new generation of artificial ankles designed to work more like the joint youre born with, a move specialists hope finally will offer less pain and more function to thousands who hobble although its too soon to be sure.
“These third-generation prostheses really mimic a natural ankle, which is really what makes them different,” says ankle specialist Dr. Steven L. Haddad of the Illinois Bone and Joint Institute and an orthopedic surgery professor at Northwestern University.
If the newer implants pan out, its a market ripe for growth. More than 200,000 people seek care for ankle pain annually, with few options for the severely damaged. More than 8,000 a year get their ankle bones fused, a last-ditch treatment after years of suffering, while surgeons perform between 2,000 and 2,500 ankle replacements.
While Medicare pays for ankle replacements, which Haddad says can reach $50,000 including a three- to five-day hospital stay, many other insurers dont. And a review in Septembers Journal of the American Academy of Orthopedic Surgeons cautions that so far, there is little research to tell how long newer versions will last – and that few hospitals have much practice in implanting them.
But for Sivia, the surgery restored an ability to walk that the 39-year-old thought hed forever lost. His leg was crooked from a series of breaks that began in childhood and included a crushing ankle fracture at 28. A decade of pain later, he sought out Haddad. Then he spent 17 months on crutches, with external pins holding bones in place, as Haddad rebuilt his leg. The last surgery, the ankle implant, came in July.
“When I got to rake my own lawn – Ive done it three times just because I can,” the Waukegan, Ill., man said with a laugh. “Im riding my bike, Im doing all the things everybody else is doing.”
Haddad says ankle sufferers tend to move like a sidewinder snake, one foot gingerly turned out to the side while the other foot does the heavy pushing to walk. They might have standard arthritis. But usually, fractures from years earlier, sometimes broken ankles, but often broken legs that left the entire lower limb out of alignment simply made the ankle and its cushioning cartilage wear out.
Fusion eliminating the pain causing friction by permanently connecting ankle bones so they wont move is usually an easy operation, with about 5 percent who fail to heal. The disadvantage is a stiff ankle that limits the foots range of motion and eventually causes a domino effect, wearing out smaller joints in the foot to cause more pain until they, too, are fused.
Hence the quest for artificial ankles that would allow a fully flexible foot and normal gait.
Thats not an easy task. The ankle joint is smaller than the hip and knee and must absorb more force than its sister joints, Dr. Keith Wapner of the University of Pennsylvania told a recent American Academy of Orthopedic Surgeons meeting.
The Food and Drug Administration began clearing so-called third-generation ankle implants in 2005, versions that Wapner expects to last longer. Each model is slightly different but consists of two attached parts. Surgeons drill a tunnel into the lower leg bone and slide in the stem of the artificial joint. A bottom piece connects to the top of the foot. Thin plastic hooked to one side functions as cartilage. Bone then grows into the implant, holding it in place.
So which is better, fusion or replacement?
It all depends on age and activity. Even if these new ankles last more than a decade as Haddad expects, someone who jogs or mountain climbs will wear theirs out faster than someone who is sedentary. Also, different patients have different risks of wound infections.
“If youre someone that does not mind having additional surgeries on your ankle in the future as a trade-off to get better function, then a replacement is a better option,” Haddad tells patients. “If you want to take care of it once, you have to opt for a fusion.”
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EDITORS NOTE – Lauran Neergaard covers health and medical issues for The Associated Press in Washington.
Source: orast