KNEE REPLACEMENT

What It Is
When the knee joint becomes severely diseased, knee replacement surgery (also known as total knee arthroplasty), can help relieve pain and restore function. A surgeon cuts away damaged cartilage and bone from the kneecap, shinbone, and thighbone and replaces it with a prosthesis, or artificial joint. The new joint is normally made of high-grade plastics, metal alloys, and polymers.

Who’s It For
A knee replacement may beneficial if you have enough joint pain that it limits that activities like climbing stairs, walking, getting in and out of chairs, or you have chronic knee stiffness and swelling that makes bending or straightening the knee difficult. You should have tried other methods to improve symptoms such as rest, weight loss, physical therapy, a walking aid like a cane, and medications without success prior to knee replacement.

Standard Treatments
Conventional knee replacement
An 8- to 11-inch incision is made through the muscles and tendons of the knee and a metal and plastic artificial joint is inserted in place of the worn one. Expect a three- to five-day hospital stay, up to a week of in-patient rehab followed by extensive physical therapy, and as much as six months to heal. Despite that, this classic, tested approach is still the most widely used because it practically guarantees excellent results.

Minimal (small) incision total knee
This giant leap in knee replacement came to the fore in 2004, opening the possibility of new knees for a younger, more active population. While the joint itself is the same as in a conventional knee, the surgical technique is vastly different. Using a small three- to five-inch incision, the surgeon removes sections of joint bit by bit and eliminates cuts through the major muscles and tendons that power the knee.

Advantages
Recovery from a minimal knee replacement is about one-third faster than a conventional, and there’s less pain because more of the knee structure remains intact. Patients leave the hospital in two days and go directly home or to a brief rehab stay. Canes are tossed in less than a month. Studies show that function and longevity are as good as or better than conventional knees when done in the right hands. At Virtua Health in Voorhees, Dr. Scott Schoifet is offering healthy, active, under-55-year-old mini-knee candidates an overnight or even out-patient option. “It’s much less costly to the health system,” he says “and really lessens the risk of picking up a hospital-based infection.”

Disadvantages
“Minimal incision is far more technically challenging and difficult than conventional. It takes longer and requires a whole specially trained team,” notes Pennsylvania Hospital orthopedist Dr. Jess Lonner, a mini-knee pioneer who has done 1,000 of them. “The skill of the surgeon is critical.”

Partial knee
If you’re young and active and your arthritis pain is limited to one of the knee’s three compartments, you might want to consider fixing only the damaged third. Partial knee surgery preserves the healthy bone and saves the major ligaments. While England’s been doing it for 15 years, it’s been less popular here because it’s not easy to do and may not eliminate the need for a total in the future.

At the 2008 orthopedic convention, everyone was wild about a new robotic-assisted system for partial knees. Pennsylvania Hospital is one of eight sites in the country testing it. Dr. Jess Lonner did the procedure on a 62-year-old man, who was riding his bike and mowing the lawn a week after surgery. Ask your doctor about it.

Gender knees
Traditionally knee replacements came in varied sizes. Now there are knees shaped and contoured for different situations — left leg, right leg, Asians and females. Women, for instance, have a wider pelvis and a narrower knee than men, and the angle where the leg bone meets the knee cap is different. The gender knee is made to more naturally fit their anatomy.

The OtisKnee
“This is the knee of the future!” declares Bryn Mawr orthopedic surgeon Dr. Joe Vernace. Just a year ago he was one of 12 doctors in the country using OtisKnee technology. Now there are more than 400. Previous advancements in knee replacement centered around improvements in the size, shape and material of the joint. The OtisKnee is a computer-assisted technique that revolutionizes the surgery itself. In simplified terms, a California company takes a MRI image of the knee and creates 3-D computer models of the previously healthy and now damaged knee. From these, they develop a patient-specific, plastic cutting guide that shows the surgeon precisely where to cut the bone and at what angle to insure a fit that perfectly matches the patient’s own anatomy. “Patients are off a walker in a week,” says Vernace, “and in a month, 80 percent no longer need a cane. But even better, the new knee feels as normal as the original.”


Living With Knee Replacement
Undergoing any surgery can have risks and complications, but assembling the right team of doctors and surgeons is the first step to a successful outcome. Luckily, Philadelphia is full of talented doctors and cutting-edge facilities to help you do just that.