According to epidemiologic data, there appear to be biologically derived and behaviorally influenced disparities in knee osteoarthritis (OA) and treatment with total knee arthroplasty (TKA). Specifically, the burden of disease is significantly higher for women. Women tend to develop knee OA more frequently than men and present with more advanced disease at the time of TKA. “Factors such as weight and activity levels are likely part of the reason for these trends,” says Mary I. O’Connor, MD. “Furthermore, studies are showing that women are typically more obese than men. There may also be sex-based differences in vitamin D receptors, inflammatory markers, or cartilage make-up.”

Unconscious Gender Bias

According to Dr. O’Connor, healthcare providers may be unconsciously biased based on gender. “Patients and providers need to become aware of this potential bias,” she says. “Clinicians should be aware that they could have a bias and make conscious efforts to treat patients equally.” She adds that patients will often pick up on non-verbal clues in providers with unconscious biases. Physicians should be cognizant of the profound influence they have on the decisions patients make.


In a recent Canadian study of standardized patients with moderate knee OA, orthopedic surgeons were much more likely to recommend surgery to men than to woman. Specifically, 42% of orthopedic surgeons recommended TKA to male patients but not female patients, whereas 8% recommended TKA to females but not to males. “More research is needed to further study potential disparities in treatment recommendations,” notes Dr. O’Connor. “By studying sex differences, we may be able to target therapies more effectively.”

In addition, Dr. O’Connor believes that further research is necessary to compare muscle strength in women and men with knee OA. “Decreasing muscle strength among those with knee OA has a large impact on function and endurance,” she says. “Clinical studies show differences in muscle strength between men and women, but we don’t necessarily understand why these disparities exist.”

Looking Ahead

Dr. O’Connor believes greater efforts are needed to support research on developing treatment strategies to minimize knee OA risk that specifically focus on gender differences. This includes enhancing routine outcome measurement tools to
be gender-neutral, promoting optimal pre- and postoperative function, and gaining a better understanding of the influence of unconscious bias on provider recommendations for treatment.

“Establishing effective ways to avoid biases and develop decision-support tools for guiding decision-making processes is paramount,” says Dr. O’Connor. “We should view the doctor–patient relationship as a partnership. To optimize care, healthcare providers should have an understanding of gender-based factors that play a role in knee OA and make every effort to avoid biases when recommending or providing treatment.”