Thomas Jefferson University Hospital - Joint Replacement Is Jumpin’ at Jefferson (and Elsewhere)

Joint Replacement Is Jumpin’ at Jefferson (and Elsewhere)

It may lack the “buzz” and glamour of Manolo Blahnik shoes, iPods, flat-screen TVs and pills to treat erectile dysfunction. But make no mistake: joint replacement surgery is HOT – especially among baby boomers. And it’ll be hotter still with future generations.

Total knee replacements, in particular, are growing at an almost startling rate, notes Peter F. Sharkey, MD, an orthopedic surgeon specializing in knee and hip replacement at the Rothman Institute at Thomas Jefferson University Hospital. Currently, about 450,000 total knee replacement procedures are performed annually, and studies predict that number will increase to 3.5 million by the year 2030 annually.

How does the knee work?
The knee joint functions like a hinge at the junction of two bones, the femur (thigh bone) and tibia (shin.) The ends of the bones are covered with a thick cushion of hard, white cartilage. You are given only one coating of this cartilage in your lifetime. If it is damaged or worn away, the underlying bones rub together, producing the pain and inflammation typical of arthritis.

What is arthritis?
Arthritis simply means an inflammation of a joint causing pain, swelling, stiffness, instability and often deformity. Severe arthritis interferes with a person’s activities and limits his or her lifestyle.

Courtesy of the Rothman Institute

What is a total knee replacement?
When the cartilage has worn away, an artificial knee (called a prosthesis) can take its place. The surgery to implant the prosthesis is termed a total knee replacement. Only the surface of the joint is removed - the arthritic ends of the bones are shaved off and replaced with new metal and plastic surfaces.

Growing need
While the exact causes aren’t certain, “various little things are probably causing this epidemic of knee arthritis,” suggests Dr. Sharkey, who is also Professor of Orthopedic Surgery at Jefferson Medical College of Thomas Jefferson University. One such cause is overloading of the knee joint. This is particularly prevalent among middle-aged women between 5 feet, 2 inches and 5 feet, 6 inches who are moderately overweight (170 lb.) to obese (220 lb.), thanks in part to 20 or 30 pounds gained during pregnancy that are not subsequently shed.

Diet probably accounts even more for the growing need for total knee replacement. “The knee joint can be a reservoir for fat. Fat contains arachidonic acid that stimulates inflammation and destruction of cartilage,” Dr. Sharkey says. “Complicating matters is that, unlike in past eras, it is now possible to be overweight and malnourished, thanks to a diet dominated by processed, vitamin-deficient foods like potato chips and soda. In addition, many people have deficiencies of omega-3 essential fatty acids and an excess of omega-6 essential fatty acids, due in part to consumption of processed foods overly rich in vegetable oils; this disproportionate intake can also contribute toward inflammation of the joints.”

How does the hip work?
The hip is a ball and socket joint that acts much like a ball bearing, allowing you to turn in different directions while supporting the body. At the upper end of your thigh bone (or femur) is a ball which fits into a socket. Cartilage (a layer of smooth soft tissue) covers the ball and lines the socket, and allows the ball to move easily in the socket. You are given only one coating of this cartilage in your lifetime.

Courtesy of the Rothman Institute

What is a total hip replacement?
When the hip joint has worn to the point when it no longer does its job, an artificial hip (called a prosthesis) made of metal and plastic can take its place. The surgery to implant the prosthesis is termed a total hip replacement. The hip replacement recreates the normal function of the hip. While the idea of getting an artificial hip joint may be frightening to some, it is one of the safest and most effective medical procedures.

Growing desire
Hip replacement procedures meanwhile are increasing less dramatically but steadily nonetheless. But, although the growing need for them isn’t as dramatic, the growing desire among patients is as great as that for total knee replacement. “Each of these operations has become safer, much less invasive and much less disruptive to the patient’s lifestyle,” Dr. Sharkey explains. “In addition, people are less and less willing to tolerate having any disability; we’ve developed into a culture of people who believe, ‘Why suffer? Why put up with this pain? These are my quality years; why limp around with a bad knee or hip?’

No time like the present
“Doctors are willing to act a lot quicker now for those same reasons. These are safe operations. In particular, total knee replacement procedures are generally 98 percent successful, and about 90 percent of replaced knees will still be working well 20 years later." For example, several years ago, Dr. Sharkey would likely have demurred performing a total knee replacement on a 52-year-old woman until the patient was a few years older, more disabled or the relevant technology had improved. But today, with longer life spans and active lifestyles, a person isn’t really “old” in her late 50s or early 60s, so why wait a few years? In fact, studies now show that the longer the procedure is delayed, the weaker and stiffer the joint grows, resulting in a less optimal recovery. And given the current success rate, the likelihood that new technology can further improve these procedures seems unlikely within the next several years.

Peter F Sharkey, MD

“Least invasive,” NOT “minimally invasive”
Nevertheless, Dr. Sharkey stresses that joint replacement is more involved than, say, a typical dental appointment. He and his colleagues at the Rothman Institute at Jefferson prefer the term “least invasive” to “minimally invasive” when counseling patients for that reason as well as the fact that, despite the aforementioned success rates, these procedures “are still potentially dangerous; they can cause blood clots, terrible infections or heart attacks, which is why patients should only rely on a specialist to perform them. We feel that doctors who use the term ‘minimally invasive’ are misleading the public to make them feel, because only a small incision may be required, that any doctor can perform these procedures, that they’re very simple.”

What to expect
Patients of the Rothman Institute at Jefferson contemplating a total knee or hip replacement, must plan on at least two to three months from making the decision to go forward and the actual procedure in order to prepare properly. This includes:

Seeing a cardiologist to make sure they’re healthy enough to have the operation
Undergoing preoperative counseling so that they better understand the procedure in advance, resulting in quicker recovery
Seeing a dentist if they have dental problems or infections, because having a lot of disease in the mouth causes bacteria to go through the bloodstream into the joint that’s being replaced, resulting in infection.

The procedure itself takes 30 to 45 minutes and requires only local anesthesia. Most patients gauge their post-operative pain as mild to moderate (on a scale of 3 to 5 out of 10), as compared to years ago, when they would typically describe joint replacement as the most painful experience of the lives, (i.e., 9 or 10 out of 10). In addition, physicians can now more effectively treat post-op side affects such as nausea and hypotension (low blood pressure) with medication and fluids.

“The typical patient can now be discharged from the hospital sooner – usually, within two or three days,” Dr. Sharkey concludes. “Within four to six more weeks, following physical therapy, most people are back to work.”

Make an appointment with a physician at the Rothman Institute at Jefferson online or by calling 1-800-JEFF-NOW.