Ankles may soon become the next popular “bionic joint.”
While hip and knee replacements are relatively common — doctors performed about a million of those in 2015 – ankle replacements are not. In past years, only about 6,000 ankle replacement surgeries have been performed annually in the U.S.
But that’s changing. Thanks to advances in technology, specialists are achieving good results with new artificial implants.
New Implants On the Market
“With the new implants, we’re getting more predictable results and much better outcomes than a decade or so ago,” said Dr. Keith Heier an orthopedic surgeon on the medical staff. “Ankle replacement is now a good option for many patients with advanced ankle arthritis.”
Ankle replacement – or more precisely, total ankle anthroplasty –has taken longer to perfect than knee and hip replacement, because the ankle has many moving parts. There are 28 bones and 30 joints in the foot and ankle complex and all of these can affect the success of the ankle implant. But thanks to advances in materials technology and surgical procedures, it’s making sense for more and more patients.
About 1 percent of the adult population suffers from some degree of ankle arthritis. Ankle arthritis can develop due to aging, repetitive stress or injury. As the cartilage in the ankle wears away, bones rub against bones, making walking, exercising and climbing stairs painful. Some 85 percent of cases of ankle arthritis are linked to some type of traumatic incident, such as a fall.
Ankle replacement is an option for patients with advanced ankle arthritis who have exhausted other, more conservative treatment measures, including anti-inflammatory medications, steroid injections, physical therapy and the use of braces.
“We advise patients to wait as long as possible – but not too long,” said Dr. Heier. “If there’s too much bone loss, the implant can’t be successfully installed.”
No implant lasts forever, but many studies show 10-year survival of the ankle implant in up to 90% of patients. However, as with hip and knee replacements, younger patients will likely need some type of revision procedure in the future.
Dr. Heier adds that some patients who have had fusion surgery – the only surgical option available in the past — may also be candidates for ankle replacement.
How It Works
To perform ankle replacement, surgeons make an incision in the front of the ankle, clear out any bone spurs, remove the ends of the tibia and talus bones, and then attach the implant to the remaining healthy bone.
Sometimes, a second incision in the calf is made to release the Achilles tendon, which often becomes tight in patients with ankle arthritis.
Several different implant devices are available. Dr. Heier has taught orthopedic surgeons how to perform surgery with the STAR Ankle; consulted with developers of the Agility ankle, the first commonly used prosthesis; and has extensive experience with the Salto Ankle and the Wright Medical Infinity Prophecy ankle.
“I am presently doing the Infinity Prophecy ankle most commonly due to the success of the CT-designed cutting blocks, which are specifically made to fit each patient’s ankle joint,” Dr. Heier said. “Having experience with all these devices, I can recommend the best option for each patient’s particular condition.”
Compared to previous implants, the newer models require surgeons to remove less bone, so that the bone to which the device is affixed is stronger. Also, instruments that help surgeons align the artificial joint have also improved.
Most patients will spend one or two days in the hospital after surgery. They will be in a cast for two weeks and then a boot for six weeks. Full weight bearing starts at four weeks in the boot, and most patients are wearing shoes by eight weeks. Intensive physical therapy follows.
Once healed, ankle-stressing activities like basketball or distance running aren’t recommended, but patients can enjoy walking, golfing and other daily activities without pain.
“For my patients who’ve struggled with severe ankle pain for years, they tell me this surgery has changed their lives,” said Dr. Heier.