Sports participation may increase risk of knee osteoarthritis

According to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Chicago, participating in certain sports such as soccer, as well as elite long distance running, weight lighting and wrestling may increase the risk of developing knee osteoarthritis.

Knee osteoarthritis is a common form of osteoarthritis and is caused by cartilage breakdown in the knee joint. Factors that increase the risk of knee osteoarthritis — including being overweight, age, injury or stress to the joints, and family history — can increase the risk of knee osteoarthritis.

Information about the risk of developing the disease as a result of sports participation could help prevent injuries, disability and pain. Because current data establishing a link is limited, researchers recently investigated the association between specific sports participation and the risk of knee OA. Researchers also set out to determine if joint injury contributed to an increased risk of developing OA of the knee.

"In the past, many studies evaluating the risk of developing knee osteoarthritis have grouped different types and competition levels of sport participation together," says Jeffrey B. Driban, PhD ATC, CSCS; research associate at Tufts Medical Center and lead investigator of the study. "Unfortunately, findings from those studies limited our ability to advise the public about the risk of participating in specific sports; especially at a recreational level, which may be great source of exercise for people."

In March 2011, Dr. Driban's team reviewed previous studies that investigated an association between sports participation and knee OA. These studies evaluated sport participants years after they retired from sport participation and determined if they had evidence of knee OA, needed total knee replacements or were placed on waiting list for a replacement. All subjects reviewed were male.

Once data were pulled from the previous 16 studies, participants were labeled as elite (national team/Olympic/professional) or non-elite (scholastic/recreational) athletes based on their level of play. Researchers took measures to ensure that patients with a history of knee injury were separated from those without.

Among the 3,192 people reviewed from previous studies, 8.4 percent of former sport participants had knee osteoarthritis compared to 9.1 percent of people who did not participate in sports. Although, the overall data reflects no association or slightly lower risk for former athletes, the risk for knee OA was dependent on the specific sport played and possibly the level of competition. Both elite and non-elite-level soccer players, as well as elite long distance runners, weight lifters and wrestlers were found to be at an increased risk of OA, and Dr. Driban considers this finding supportive of the need for prevention strategies for these athletes.

"The most reassuring aspect of the data is that most sports probably do not increase the risk of developing knee osteoarthritis; especially when competing at a recreational level," says Dr. Driban. "The sports that were found to increase the risk of knee osteoarthritis were sports that involve a high risk of knee injury and have lots of loading on the knee. For persons who want to reduce their risk of OA, choosing sports that have lower risk of injury, are non-contact, and low impact such as doubles tennis, swimming, and cycling are likely good choices. For athletes who choose to participate in high-risk sports like soccer, particularly at elite levels for many years, they should know they have an increased likelihood of getting osteoarthritis and should pay attention to reducing other risk factors (e.g., preventing obesity and severe joint injuries) associated with the development of osteoarthritis."

While this review of previous studies has identified some athletes that would benefit from knee OA prevention strategies, Dr. Driban's team also notes there is a need for more research in this area.

Dr. Driban further comments, "We still have considerable gaps in our understanding about the influence of sports on knee osteoarthritis. There is only limited data on non-elite sports and the increased risk that might be associated with injury, and there is no specific data on female sport participants, who make-up over 40 percent of participants in United States high school and college sports. Almost all of the research has focused on elite male sport participants. It is important for people to recognize that most sports, especially when participating at the recreational level, do not seem to increase the risk of knee osteoarthritis and still represent an excellent way to participate in health-enhancing physical activity."