Risk Factors for Osteoarthritis
The primary risk factors for osteoarthritis include older age, female sex, obesity, genetics, prior joint injury, and occupational/recreational joint overuse. 1
Patient-Level Risk Factors
Demographic Factors
- Age: Prevalence increases significantly with age, especially in those over 40 years 1
- Affects 13.9% of adults 25+ years and 33.6% of adults 65+ years 1
- Sex: Women have higher risk than men 1
- Women represent 78% of diagnosed OA cases despite being only 51% of the general population 1
- Menopausal status: Postmenopausal women have increased risk 1
- Race/ethnicity: African Americans have higher risk 2
Body Composition
- Obesity/elevated BMI: Strong and consistent risk factor across multiple studies 1, 3
- Acts through both mechanical stress and metabolic pathways 1
- Higher bone density: Associated with increased risk of hand OA 1
Genetic Factors
- Family history: Strong hereditary component 1
- Genetic predisposition: Multiple genetic variants identified 2
Joint-Level Risk Factors
Trauma and Mechanical Factors
- Prior joint injury: Significant risk factor for post-traumatic OA 1
- Moderate-certainty evidence that various knee injuries increase symptomatic OA risk 1:
- Cruciate ligament injuries
- Collateral ligament injuries
- Meniscal injuries
- Chondral injuries
- Patellar/tibiofemoral dislocations
- Fractures
- Multi-structure injuries
- Moderate-certainty evidence that various knee injuries increase symptomatic OA risk 1:
- Joint malalignment: Alters biomechanical loading 3
- Joint laxity: Particularly relevant for hand OA 1
- Greater forearm muscle strength: Associated with hand OA 1
Occupational and Activity Factors
- Occupational exposure: 1
- Heavy work activities (farming, construction)
- Frequent kneeling
- Heavy lifting
- Repetitive joint use
- Recreational activities: 1
- High-impact sports (football, hockey, sky diving)
- Military service activities
Comorbidities and Systemic Factors
- Metabolic syndrome: Associated with increased risk and inflammatory component 1
- Low-grade systemic inflammation: Contributes to OA development and progression 1
- Diet: Particularly relevant for antioxidant intake 4
- Gut microbiota alterations: Emerging evidence suggests link between gut microbiome and OA 1
Clinical Implications
Risk Factor Modification
- Weight management is crucial for prevention and management of OA 3
- Injury prevention programs may reduce post-traumatic OA risk 1
- Occupational modifications for those with high-risk activities 1
Common Pitfalls
- Overlooking systemic factors: OA is not merely a "wear and tear" disease but involves complex inflammatory processes 1
- Focusing only on single risk factors: Multiple risk factors often interact in complex ways 3
- Neglecting comorbidities: 59-87% of OA patients have at least one other chronic condition 5
- Underestimating impact: OA significantly affects quality of life, daily activities, and increases all-cause mortality risk 3, 5
Polyarticular OA
- Patients with polyarticular hand OA are at increased risk for OA at other sites (knees, hips) and should be assessed accordingly 1
Understanding these risk factors is essential for early identification of at-risk individuals, implementing preventive strategies, and developing targeted interventions to reduce the substantial personal and societal burden of osteoarthritis.