Could the first two years after a sports-related knee injury be the best time to prevent future weight gain and knee arthritis?
What is the problem?
Young people who injure their knee while playing sports are more likely to develop excess body fat and knee osteoarthritis later in life, but it is not clear when these changes begin.
How did the team study the question?
Researchers followed 186 young people (106 with a sports-related knee injury and 80 without an injury) for two years, measuring their body fat at regular time points and comparing how it changed over time.
What did the team find?
Both groups gained body fat over the two-year study period, but the amount of fat gained was similar whether or not a young person had injured their knee. There were also no clear differences between young people with ACL tears and those with other knee injuries, or between females and males. Although some injured participants appeared to gain body fat more quickly during the first six months after injury, this pattern was not strong enough to show a clear difference from the uninjured group. These findings suggest that body fat changes in the first two years after injury may be part of normal growth and development rather than the injury itself. However, because earlier research has shown that differences become apparent several years after injury, the first two years may still be an important time to help young people build healthy habits.
How can this research be used?
Healthcare providers, coaches, families, and young people recovering from a knee injury can use these findings to focus on healthy eating, regular physical activity, and rehabilitation soon after injury. Even though injured youth did not gain more body fat than their peers during the first two years, this period may offer an important opportunity to prevent unhealthy weight gain later in life and reduce the risk of post-traumatic osteoarthritis and other long-term health problems.
Cautions
Nearly half of the participants missed the final two follow-up visits, so some results were estimated using statistical methods rather than direct measurements. The study also measured body fat with bioelectrical impedance instead of the gold-standard body scan, included mostly active young people, and did not collect information on race, ethnicity, or stages of puberty. These factors mean the findings may not apply to all young people with knee injuries.
Citation
Losciale, J. M., Jansen, N. E. J., Le, C. Y., Lu, L., Xie, H., van Middelkoop, M., & Whittaker, J. L. (2026). Longitudinal changes in adiposity after a youth sport-related knee injury: Informing posttraumatic osteoarthritis prevention. Arthritis Care & Research. Advance online publication. https://doi.org/10.1002/acr.80118
Funder
This study was supported by the Arthritis Society Young Investigator Operating Grant, the Michael Smith Foundation for Health Research Scholar Award, the Arthritis Society STAR Career Development Award, the Department of Veterans Affairs BRITE-IDEAS Fellowship, the Osteoarthritis Research Society International (OARSI), and the Foundation “De Drie Lichten” (Netherlands).