Understanding Knee Pain Demographics

June 3, 2024

Unravel knee pain demographics: from gender disparities to socioeconomic factors, and their impact on knee health.

Top 10 Statistics: Understanding Knee Pain Demographics

Women are more likely to report higher knee pain severity compared to men across all Kellgren-Lawrence (KL) grades of osteoarthritis [1].
Sex differences in knee pain are present even before the onset of radiographic knee osteoarthritis (KL grade <2) [2].
Adjusting for covariates such as age, BMI, and physical activity does not fully explain the gender disparity in knee pain severity [1].
The presence of widespread pain (WSP) contributes to the higher knee pain severity reported by women [1].
Knee pain prevalence increases with age, with the highest rates observed in individuals over 65 years old [3].
Occupations involving heavy physical labor or repetitive knee bending are associated with a higher risk of developing knee pain [4].
Athletes participating in high-impact sports, such as basketball and soccer, have a greater likelihood of experiencing knee pain [5].
Socioeconomic factors, including lower education levels and income, are linked to a higher prevalence of knee pain [6].
Obesity is a significant risk factor for knee pain, with overweight individuals having a 2-fold increased risk compared to those with a healthy weight [7].
Racial and ethnic disparities exist in knee pain prevalence, with African Americans and Hispanics reporting higher rates compared to non-Hispanic whites [8].

Gender Disparities in Knee Pain

While knee pain is a common ailment affecting individuals across different demographics, research suggests that there are gender disparities in its occurrence and severity. Here, we delve into the specifics of women's pain severity and the association of knee pain with widespread pain in women.

Women's Pain Severity

According to a study published on NCBI, women reported higher pain severity across all KL grades in unadjusted analyses and in analyses adjusted for all covariates except WSP. The differences in pain severity further decreased with adjustment for WSP and were significant for KL grade ≤2 and 2.

Furthermore, women generally reported greater pain at all KL grades compared with men, especially in the presence of PFOA. These sex differences were found prior to the onset of radiographic knee OA (TFOA KL grade <2) and were present regardless of adjustment for covariates in knees without PF or TFOA.

Moreover, women consistently reported greater or equal knee pain compared with men at each KL grade, despite similar levels of radiographic knee OA. This demonstrates a disparity in disease impact for knee OA between men and women, and this disparity exists prior to the onset of radiographic knee OA.

Pain Severity	Women	Men
KL Grade ≤2 and 2	Higher	Lower
Presence of PFOA	Higher	Lower
TFOA KL Grade <2	Higher	Lower
Radiographic Knee OA	Equal or Higher	Lower

Association with Widespread Pain

The same study also reported that the presence of widespread pain was associated with significantly greater knee pain at all KL grades in women. This underlines the relationship between systemic pain and localized knee pain in women.

These findings highlight the need for further research into the factors contributing to the higher pain severity reported by women. It also underscores the importance of considering gender differences when diagnosing and treating knee pain.

Demographics and Knee Pain

Understanding the demographics related to knee pain can provide valuable insights into prevalence, potential causes, and effective treatment strategies. Age, athletic activity, and youth can all play significant roles in knee pain occurrence and severity.

Age Group Variances

Knee pain prevalence significantly varies by age group. It's the number one cause of disability in individuals over 50 years old, with an estimated 25% of the UK general population in this age group affected by knee pain [1]. Tailored strategies to address knee pain are essential for individuals in this age group to continue enjoying their lives.

Age Group	Knee Pain Prevalence
50+ years	25%

Athletes and Knee Pain

Knee pain is also common among athletes due to the high-impact nature of many sports. In particular, Patellofemoral Pain Syndrome (PFPS) stands out as a prevalent issue. According to a study cited by the NCBI, among patients aged 10 to 49 reporting to a sports medicine clinic, 70% of the PFPS cases were between the ages of 16 and 25. The study also found the diagnosis of PFPS accounted for 19.6% of all injuries in females and 7.4% of all injuries in males.

Furthermore, the prevalence of PFPS was reported to be approximately 1.5 times greater in females compared with males, emphasizing the importance of gender-specific considerations in knee pain demographics and treatment among athletes.

Gender	PFPS Prevalence
Females	19.6%
Males	7.4%

Teen and Young Adult Impact

While knee pain is more common in older individuals, it also affects teens and young adults. Common causes in this age group include trauma to the knee, overuse, and certain medical conditions [1]. Treatment options generally include applying ice, taking anti-inflammatories, and resting to allow the affected area to heal.

Understanding these demographic variances can guide both prevention and treatment strategies for knee pain, aiding in the development of more effective and personalized approaches to knee health.

Knee Pain Prevalence

Understanding the prevalence of knee pain allows us to develop a more comprehensive picture of knee pain demographics. This involves reviewing epidemiological insights and examining common conditions such as patellofemoral pain syndrome.

Epidemiological Insights

Epidemiological studies provide valuable data regarding the prevalence and distribution of knee pain among different populations. These studies highlight significant disparities in the experience of knee pain.

A noteworthy finding is the gender disparity in knee pain, with women consistently reporting greater or equal knee pain compared to men at each KL grade [2]. This disparity in pain severity exists even in the presence of similar levels of radiographic knee osteoarthritis (OA).

Gender	Reported Knee Pain
Women	Greater or equal to men
Men	Less or equal to women

These findings suggest a disparity in the disease impact for knee OA between men and women. It's also worth noting that this difference exists prior to the onset of radiographic knee OA.

Patellofemoral Pain Syndrome

One common condition contributing to knee pain prevalence is patellofemoral pain syndrome (PFPS). This condition is characterized by pain in the front of the knee and around the kneecap.

The association between PFPS and the prevalence of knee pain is particularly significant among women. Studies show that women generally report greater pain at all KL grades compared with men, especially in the presence of patellofemoral osteoarthritis (PFOA) [2].

Condition	Reported Pain in Women
Patellofemoral Pain Syndrome	Greater than men

Furthermore, the presence of widespread pain is associated with significantly greater knee pain at all KL grades. This underscores the importance of understanding and addressing the factors contributing to widespread pain in order to effectively manage knee pain.

These insights into knee pain prevalence, together with other demographic data, can inform strategies for prevention, treatment, and management of knee pain. By understanding the differing experiences and impacts of knee pain across various demographics, health professionals can work towards more personalized and effective care plans.

Knee Osteoarthritis Statistics

In the context of knee pain demographics, understanding osteoarthritis statistics is essential. Osteoarthritis (OA) is a common form of arthritis that affects millions worldwide, with the knee being one of the most affected areas.

Symptomatic OA Data

Data reveals that symptomatic knee osteoarthritis is common, especially among older adults. About 13% of women and 10% of men aged 60 years and older have symptomatic knee osteoarthritis. The proportions of people affected with symptomatic knee osteoarthritis are likely to increase due to the aging of the population and the rate of obesity or overweight in the general population [3].

In a cross-sectional study in Greece, symptomatic knee osteoarthritis was observed in 6% of the population, with a significantly higher prevalence among women compared to men, and increasing significantly with age.

It's also important to note that females, particularly those ≥55 years, tend to have more severe knee osteoarthritis than males, especially after menopausal age. Middle-aged women had a high prevalence of moderate-to-severe knee osteoarthritis [3].

Age Group	Prevalence (Women)	Prevalence (Men)
60 years and older	13%	10%
Middle-aged (≥55 years)	High	Moderate to Severe

Racial Disparities

Studying the knee pain demographics also reveals racial disparities. For instance, African Americans have a slightly higher prevalence of knee symptoms, radiographic knee osteoarthritis, and symptomatic knee osteoarthritis compared to Caucasians. They also have a significantly higher prevalence of severe radiographic knee osteoarthritis [3].

Furthermore, studies have shown that African Americans (AAs) are 50-65% more likely to have radiographic knee osteoarthritis (rKOA) and symptomatic knee osteoarthritis (sxKOA) than whites in the United States. Racial differences in knee osteoarthritis prevalence appear to be more pronounced among women than men [4].

Race	Prevalence (Knee Symptoms)	Prevalence (Radiographic Knee OA)	Prevalence (Symptomatic Knee OA)
African Americans	Higher	Higher	Higher
Caucasians	Lower	Lower	Lower

These statistics underscore the importance of considering demographic factors when studying knee osteoarthritis, as they can provide insight into the populations most at risk and guide targeted interventions.

Socioeconomic Factors

In addition to individual health habits and genetics, socioeconomic factors also play a role in knee pain demographics. This section will discuss the influence of education and income levels on knee osteoarthritis (OA) and knee surgery.

Education and Knee OA

Education level is a significant factor in the prevalence of knee OA. Research indicates a higher prevalence of this condition among individuals with lower levels of education. For instance, in the US, individuals with ≤8 years of education were significantly associated with radiographic knee OA and knee pain compared to those with ≥13 years of education.

In another study, it was seen that individuals with ≤ 9 or 9–12 years of education were 25-30% more likely to have radiographic knee OA compared to those with ≥12 years of education [4].

Education Level	Likelihood of Radiographic Knee OA
≤ 8 years	High
9-12 years	25-30% Higher
≥ 13 years	Lower

Income and Knee Surgery

Income also plays a significant role in knee health, particularly when it comes to knee surgery. Those with lower income, lower wealth, and higher deprivation were less likely to have knee joint replacement surgery, while obesity was associated with increased hazards of knee joint replacement surgery. The direction of the associations for socioeconomic position and obesity with knee joint replacement surgery were in opposite directions, indicating no mediation by obesity [5].

Interestingly, over a mean follow-up of 4.7 years, 144 people with symptomatic knee osteoarthritis reported having at least one knee joint replacement surgery. The rates of knee joint replacement surgery were similar across different educational and occupational groups, but gender differences were observed, with women less likely to undergo knee joint replacement surgery compared to men in lower educational and occupational groups [5].

Income Level	Likelihood of Knee Joint Replacement Surgery
Lower	Less Likely
Higher	More Likely

Understanding these socioeconomic factors can help healthcare providers and policymakers develop targeted interventions to address knee pain demographics and improve overall knee health.

Occupational Impact on Knee Health

Work-related activities can significantly impact knee health. Certain physically demanding jobs and specific job titles are associated with increased odds of knee osteoarthritis (OA), a common cause of knee pain.

Physically Demanding Jobs

Physically demanding occupations are often linked to an increased risk of knee OA. A synthesis of 71 studies suggested increased odds of knee OA for different physically demanding jobs and occupational activities compared to sedentary occupations and/or low exposure groups. Specifically, the agricultural and construction sectors, which typically involve heavy lifting, frequent climbing, prolonged kneeling, squatting, and standing, carried increased odds of knee OA.

Occupation Type	Odds Ratio (OR) for Knee OA
Physically demanding jobs	1.52 (95% CI: 1.37, 1.69)
Sedentary jobs	Reference group

The odds of knee OA were greater in males, industry-based studies, and studies assessing lifetime occupational exposures.

Specific Job Titles Impact

Certain job titles have been associated with a higher risk of knee OA. These include farmers, builders, metal workers, and floor layers. Occupational lifting, kneeling, climbing, squatting, and standing were all associated with higher odds of knee OA compared to sedentary workers.

Houseworkers also had up to a 93% increased odds of developing knee OA, which aligns with a previous study that found a 92% increased prevalence of lower extremity pain in homemakers.

Statistically significant higher odds of knee OA were also found in miners, especially coal miners, with an odds ratio of 1.47. Cleaners, craftsmen, and service workers also had a statistically significant increased odds of knee OA.

Job Title	Odds Ratio (OR) for Knee OA
Houseworkers	1.93
Miners	1.47 (95% CI: 1.11, 1.95)
Cleaners, Craftsmen, Service Workers	(Not specified, but statistically significant)

The association between knee OA and occupations indicates the importance of workplace ergonomics and preventive measures to protect knee health. More studies are needed to further explore these relationships and develop effective interventions to reduce the occupational impact on knee health.