Experts at the University of Texas Southwestern Medical Center say that examining sex-specific variations in the knee joint as early as childhood can prevent women from developing knee osteoarthritis (OA) at a higher rate and severity. Their clinical data analysis, published in Osteoarthritis and Cartilage, emphasizes the importance of understanding knee anatomy, biology, and juvenile sports injuries in managing OA risks.

The most common type of arthritis is osteoarthritis, which affects around 33 million Americans, according to the Centers for Disease Control and Prevention (CDC). Knee and hand joints worldwide are particularly vulnerable to OA. Despite decades of studies demonstrating that OA differs by gender, the biological causes of females' increased knee OA risk remain unknown. The increase in early-life knee injuries necessitates the development of preventative techniques, especially for women.

"The frequency and severity of sports-related injuries are on the rise, as it's more common to see youths engaged in specialized sports with high demand at an early age," said Dr. Paula Hernandez, lead author and Instructor of Orthopaedic Surgery and Biomedical Engineering at UT Southwestern. 

"Young female athletes have a higher risk of ACL (anterior cruciate ligament) injuries compared to young male athletes, and we know these types of injuries can likely develop into OA later in life," she added.

The researchers investigated clinical data from numerous knee tissues, finding significant aspects underlying sex differences based on human anatomy, physical activity, and metabolic parameters. To compare developmental stages, they divided the population into four groups: childhood (0–11 years), youth (12–18), early adulthood (19–49, premenopause), and late adulthood (50 and older, postmenopause). 

They found that sex hormones alone cannot explain the differences in articular cartilage, meniscus, and ACL between males and females before puberty. While hormones such as estrogen and testosterone are important, sex chromosomes also have an impact. Understanding these roles may assist doctors in managing hormonal influences on OA risk. 

The review also discovered changes in amino acid and other metabolite levels between males and females, indicating metabolic differences. 

Anatomical and metabolic differences and social factors influencing lifestyle all increase the chance of physical activity and injury in early life. These changes increase women's OA risk. 

Dr. Hernandez's lab plans to use these findings to create sex-specific student exercise and wellness programmes. She hopes that by demonstrating evidence that sex disparities do not only occur at menopausal age but also start early in life, we can raise awareness among other researchers to initiate this practice.