Every year more than 30 million Americans limp into doctors’ offices complaining of pain, stiffness and swelling in their joints. In most cases, they’re suffering from osteoarthritis, a degenerative process affecting such weight-bearing joints as the knee, hip and spine. Despite the preconceived notion that arthritis is reserved for brittle old ladies, it affects people of all body types and ages. Indeed, in the last decade, it’s become a leading cause of doctor visits for baby boomers.

Thanks to our national obsession with fitness, the formerly young generation has a tendency to engage in high-impact activities that stress aging knees and hips. This result is a booming orthopedic industry. A recent study, released at an annual meeting of the American Academy of Orthopaedic Surgeons, projects a 673 percent increase in knee replacement surgeries alone over the next 25 years.

How do our bodies get into such trouble?

Minor trauma and overuse cause cartilage to wear over time, says Dr. Adam Bright, a board-certified orthopedic surgeon with Schofield, Hand, and Bright Orthopaedics.

“As we age, cartilage can become brittle and tear. Because baby boomers are conscious about staying healthy, they devote more time to exercise. When they overdo it, the results are often stress fractures, strain on bones, and cartilage damage.”

There’s even a word for it: “Boomeritis.”

The term was coined by the American Academy of Orthopaedic Surgeons (AAOS) to describe active people of the baby boomer generation “who are pushing their bodies past what their musculoskeletal systems can endure,” says Bright.

Wait a minute. Are doctors suggesting people of a certain age shouldn’t exercise? We thought exercise was good for you!

Exercise is good for you, explains Bright. “But no matter how old you are, you need to be mindful of gradually extending the limits of exercise. It’s called smart training. “

Bright and other orthopedic experts suggest that if we want to avoid damage to our joints, we should engage in a balanced fitness program of walking, swimming, cycling, and stretching exercises. If we already suffer from pain and inflammation, it’s best to avoid exercises that place excessive stress on the joints. Aerobic workouts, running or competitive sports can do more harm than good.

A marathon runner and Iron Man contender, Bright doesn’t dismiss the value of high-impact exercise. “There’s no proof,” he says, “that running damages hips and knees or ankles unless the person already has had some damage to these areas. In fact, there are tremendous health benefits in keeping our muscles strong. Running is like a piston pushing the cartilage into the joint, literally bathing the joint with nutrition. But if you’re experiencing pain, you probably should switch to low-impact exercises like bicycling and swimming.”

Dr. Daniel S. Lamar Jr. is an orthopedic surgeon with Coastal Orthopedics and Sports Medicine who serves as consultant to the Tampa Bay Buccaneers, the Pittsburgh Pirates, the U.S. soccer team, IMG Bollettieri Academy and various area high schools. He says the most common problem he sees among non-athletes from the boomer generation is joint degeneration, particularly in the knee.

“The surfaces within the knee begin to break down and slowly wear out,” he says. “Not to say that everyone who is active is destined for joint-wear problems, but activity level does play a role. Weekend warriors can experience the same injuries as professional athletes but at different rates and magnitude. And, unlike professional athletes, they don’t always have the backup support system.”

Both Lamar and Bright see more knee problems in heavy and obese patients. “Obese people show a 70 percent higher incidence in knee deformities,” says Bright. “It’s interesting, because obesity doesn’t seem to affect the hip.”

So what’s a physically active adult to do about hip and or knee pain? Go to the family doctor, suggests Bright. He or she will know if you need to see an orthopedic specialist. If you do, that doesn’t always mean surgery.

“Surgery is not our first treatment option,” he says. “We’ll review exercise regimes and lifestyle. After making a diagnosis, we may try anti-inflammatory treatments, physical therapy, and other measures. Our first step is to control the disease. I have found that, by far, the majority of patients are managed conservatively without surgery. However, if surgery is indeed the best option, then it is clearly recommended.”

Lamar agrees. “I think of surgery as a last resort; not as the first line of management. My goal is to maintain the native knee for as long as possible. Depending on the condition of the joint, we can work with steroid injection therapies, joint lubrication injections—even weight reduction. We start with less invasive therapies and, if necessary, move to more involved treatments. For instance, there are cartilage restoration techniques that allow us to prolong the life of the articular surface that coats the ends of our bones in our joints.”

When cartilage is so worn away it no longer protects the bone, partial and even total joint replacement is necessary. If the joint is only partly damaged, a surgeon may be able to repair or replace just the damaged parts (also known as a hemi arthroplasty). When the entire joint is damaged, however, a total joint replacement, or arthroplasty, is performed. As advances in orthopedic medicine improve, total joint replacement is becoming a viable solution for people suffering joint pain—and a lucrative business for those in the orthopedic industry. In 2004, more than 650,000 total joint replacements were performed in the United States.

In a total hip or knee joint replacement, the surgeon removes the damaged parts and inserts prostheses or implants. In the knee, the damaged ends of the bones and cartilage are replaced with metal and plastic surfaces that are shaped for optimal knee movement and function. During this procedure, the surgeon replaces the upper end of the femur with a metal ball attached to a stem that is wedged into the femur. A plastic socket is implanted into the pelvis to replace the damaged socket. The prosthesis is generally composed of two parts—a metal piece that fits closely into a matching plastic piece. Typically, a new joint will last between 15 and 20 years.

Although still controversial, hip resurfacing is being performed as an alternative to total hip replacement, especially on younger patients. Rather than replacing the entire hip joint, the surgeon shaves a few millimeters of bone inside the joint and then caps it with an implant. This surgery usually affords greater stability in the new joint and also increases range of motion, which younger and more active patients demand.

Bright says he remains skeptical about the potential benefits of this treatment for older patients. Weakening the femoral neck, he says, “could result in premature fracture and late failure of the prosthesis in patients who later develop osteoporosis.” On the other hand, he says, “preservation of the femoral neck decreases the chance of a difference in the length of the leg after surgery.” This sometimes happens in total hip replacement surgery.

The good news is that 90 percent of joint replacement patients report improved mobility and a significant decrease in pain within weeks. That said, they need to remain vigilant about caring for their bodies for the rest of their lives. This means avoiding high-impact exercises and sports—and having a close and personal relationship with their physical therapist.

“As far as I’m concerned, it’s 50 percent surgery and 50 percent physical therapy,” says Diane Tauber Schultz, co-owner of Canvas Café in Sarasota. After a moped accident in the Bahamas six years ago, during which she suffered a broken leg and trauma to her right hip, this 52-year-old former runner and athlete has since undergone six major surgeries, two of them on her hip for damaged cartilage. “You can have the best surgeon work on you, and if you don’t follow his after-surgery directions you’ll have nothing but trouble,” she says.

Determined “not to limp the rest of my life,” Tauber Schultz works with her physical therapist twice a day. “Find the best physical therapist possible who works in sync with your surgeon,” she advises. “A good surgeon will be very specific about the therapeutic regime. But you have to follow it! There’s no reason you can’t return to the way you felt before hip or knee surgery. Before my accident I played tennis and golf and was very active. I want to do that again. I won’t settle for less.”

Bright says he looks for that kind of attitude in potential joint replacement patients. “Total joint replacement is the last resort,” he says. “But when we do it, the results are wonderful. In fact, the joints often outlive the patient. One of my patients was 92 years old, living in a nursing home and in constant pain. After we replaced his hip, he moved out of the nursing home, got married and was back playing golf and enjoying life. It’s incredibly rewarding to see a patient do so much better after surgery. It’s success stories like his that make me realize how much I love my job!”

Tips for exercising safely.

· Always take time to warm up and stretch before physical activity. Research studies have shown that cold muscles are more prone to injury. Warm up with jumping jacks, stationary cycling, or running or walking in place for 3 to 5 minutes. Then slowly and gently stretch, holding each stretch for 30 seconds.

· Don't succumb to the "weekend warrior" syndrome. Compressing your physical activity into two days sets you up for trouble and doesn't increase your fitness level. Try to get at least 30 minutes of moderate physical activity every day. If you're truly pressed for time, you can break it up into 10-minute chunks. Remember that moderate physical activity can include walking the dog, working in the garden, playing with the kids and taking the stairs instead of an elevator.

· Take lessons and invest in good equipment. Whether you're a beginner or have been playing a sport for a long time, lessons are a worthwhile investment. Proper form and instruction reduce the chance of developing “overuse” injuries like tendonitis or stress fractures. Lessons at varying levels of play for many sports are offered by local park districts and athletic clubs. Select the proper shoes for your sport and use them only for that sport. When the treads start to look worn or the shoes are no longer as supportive, it is time to replace them. 

· Listen to your body. As you age, you may find that you are not as flexible as you once were or that you cannot tolerate the same types of activities that you did years ago. While no one is happy about getting older, you will be able to prevent injury by modifying your activity to accommodate your body's needs. 

· Use the 10 percent rule. When changing your activity level, increase it in increments of no more than 10 percent per week. If you normally walk two miles a day and want to increase your fitness level, don't try to suddenly walk four miles. Slowly build up to more miles each week until you reach your higher goal. Also use the 10 percent rule as your guide for strength training and increase your weights gradually. 

· Develop a balanced fitness program that incorporates cardiovascular exercise, strength training and flexibility. In addition to providing a total body workout, a balanced program will keep you from getting bored and lessen your chances of injury.

· Add activities and new exercises cautiously. No matter if you've been sedentary or are in good physical shape, don't try to take on too many activities at one time. It's best to add no more than one or two new activities per workout.

· If you have or have had a sports or orthopedic injury like tendinitis, arthritis, stress fracture or low back pain, consult an orthopedic surgeon who can help design a fitness routine to promote wellness and minimize the chance of injury.

SOURCE: American Orthopaedic Society for Sports Medicine and American Academy of Orthopaedic Surgeons, www.orthoinfo.org.