Pan F, et al. - Over 10.7 years, researchers identified and validated knee pain phenotypes across different pain-related domains in an older population. With follow-up at 2.6, 5.1, and 10.7 years, 963 participants (mean age 63 years) from a population-based older adult cohort study were studied. Researchers identified three pain phenotypes, which were high prevalence of emotional problems and low prevalence of structural damage (Class 1; 25%), high prevalence of structural damage and low prevalence of emotional problems (Class 2; 20%); and low prevalence of emotional problems and low prevalence of structural damage (Class 3; 55%). Compared with Class 3, greater BMI, more comorbidities, a higher prevalence of radiographic knee OA and knee structural pathology were seen in the participants in Class 1 and 2. Class 1 consistently reported more pain sites and greater WOMAC pain vs Class 2 and 3. Researchers found that pain perception is exacerbated by the interaction of psychological and structural factors, suggesting the need for tailored treatment approaches for older people with knee pain in clinical practice.