Chronic knee pain forces more than half a million people to undergo knee replacement surgery each year and for decades, doctors asked younger patients to live with the pain to avoid revision surgery a decade down the road. Thanks to new technology, those days are officially over.
Charles Thompson's workout routine used to be high-impact until a knee injury shut him down.
"Day in and day out; pain, pain, pain," said Thompson. "I can't even explain the pain."
Thompson used to play college football but after graduation, the pain kicked in and after a few years, it all went downhill.
"In the last three years I stopped going into the weight room because of pain," said Thompson.
The problem with older knee replacements is the material. The top portion is made of cobalt chrome which is sturdy but wears down the plastic lower portion.
"You get a scratch on the metal but then that metal as the knee moves, starts rubbing on the plastic," said David Watson, doctor at Tampa's Florida Orthopedic Institute. "It essentially becomes sandpaper, rubbing the plastic away."
Watson has the solution, verilast technology.
Verilast technology is a metal alloy, oxinium, that has the feel of a ceramic and is supported by new Food and Drug Administration (FDA) approved evidence.
The smoother surface means less scratching and wear. It can last 30 years, double of the life of the old chrome version, only 15 years.
Simulations show that after three decades, the alloy has 81 percent less wear than three years of the chrome.
"There's a real benefit with wear characteristics without the downside of ceramic in the knee," said Watson.
One month after surgery, Thompson has been able to hit the weights again after three full years on the sideline.
"Now, that I'm able to do the swimming and go into the weight room, I'm very happy again," said Thompson.
And while he may be sore tomorrow, the real benefit is a knee that will last as long as he does.
The FDA cleared the new evidence for verilast in 2010 and long-term studies are underway.
WHAT YOU DON'T KNOW ABOUT YOUR KNEE: The knee is the largest joint in the body. Normal knee function is required to perform most everyday activities. The knee is made up of the lower end of the thighbone (femur), which rotates on the upper end of the shin bone (tibia), and the kneecap (patella), which slides in a groove on the end of the femur. Large ligaments attach to the femur and tibia to provide stability. The long thigh muscles give the knee strength.
DO YOU NEED A NEW KNEE? Most patients who undergo total knee replacement are age 60 to 80, but orthopedic surgeons evaluate patients individually. Recommendations for surgery are based on a patient's pain and disability, not age. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.
NEW KNEES: THE SOLUTION: Based on in-vitro wear simulation testing, the LEGION Primary Knee System with VERILAST technology is expected to provide wear performance sufficient for 30 years of actual use under typical conditions. The results of in-vitro wear simulation testing have not been proven to quantitatively predict clinical wear performance. Also, a reduction in total polyethylene wear volume or wear rate alone may not result in an improved clinical outcome as wear particle size and morphology are also critical factors in the evaluation of the potential for wear mediated osteolysis and associated aseptic implant loosening.
NEW KNEES: THE TECHNOLOGY: Previously, new knees were made from a top portion of cobalt chrome, and a lower portion of plastic. While this combination is proven to function well, normal activities force the coarse surface of the cobalt to wear-down the plastic - which results in a shorter lifespan of the knee. New technology allows for a smoother metal alloy (Oxinium) to be used instead of cobalt chrome - which decreases basic wear-and-tear, and increases the lifespan of the knee.
SURGICAL COMPLICATIONS: The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in fewer than two percent of patients. Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery. Blood clots in the leg veins are the most common complication of knee replacement surgery. Your orthopedic surgeon will outline a prevention program, which may include periodic elevation of your legs, lower leg exercises to increase circulation, support stockings, and medication to thin your blood.
FOR MORE INFORMATION, PLEASE CONTACT:
Smith & Nephew Verilast Technology