While prosthesis makers are changing designs, materials, and manufacturing methods to try to lengthen the life of artificial knees and hips, surgeons are refining techniques or developing new ones to try to improve the outcomes. Doing surgery through smaller incisions and performing less radical surgeries are among these efforts.
People are seeking minimal-incision knee and hip replacement surgery, says Engh. Instead of the traditional 6- to 12-inch-long incision used in a standard total knee replacement, some surgeons are performing the surgery through a 4- to 5-inch incision. And instead of the typical 10- to 12-inch incision in a total hip replacement, surgeons are operating through one 4-inch cut or two 2-inch cuts.
"The [minimal-incision surgery] technique minimizes trauma to muscles, tissue and tendons and has less bleeding during surgery," says Garino. Patients have less pain after surgery, enabling them to walk with full weight sooner. The hospital stay is usually reduced as well.
"There are many advantages as long as we don't compromise our ability to put the implants in correctly," says Engh, adding that minimal-incision surgery is a more difficult operation to perform. "If you assemble a model ship on a desktop, it's easier to do, but if you try to assemble it within a bottle it is technically more difficult," he says. The technical difficulty also adds to the operating time. "The longer a patient is in surgery, the higher the risk of infection," says Engh.
Not all patients are candidates for minimal-incision surgery. People, who are obese, have had previous hip or knee surgery, or those with unusual anatomy may be excluded, says Garino.
Minimally invasive surgery is another option for some patients. At Sinai Hospital, Mont performs a minimally invasive total knee replacement through an incision of 4 to 6 inches, bending the joint through the opening to expose different parts of it to work on. In a standard knee replacement, the entire joint is visible through a longer incision. Mont uses cutting procedures, leg positioning, and techniques that do not involve dislocating parts of the knee as in traditional replacement.
Even as researchers and surgeons continue to offer more options in prostheses and surgical procedures, Garino says the current technology is hard to beat. A hip or knee replacement is likely to last 20 years, he says. "The average patient takes a million steps a year. I challenge you to go home and find something in your house that you use a million times a year that has lasted for 20 years with no maintenance."
Linda Bren is a staff writer for FDA Consumer.
For More Information
American Academy of Orthopedic Surgeons
(800) 346-AAOS (346-2267)
National Institute of Arthritis and Musculoskeletal and Skin Diseases
(877) 22-NIAMS (226-4267) TTY: (301) 565-2966
"All You Need to Know About Joint Surgery," © 2002, Arthritis Foundation