Trajectories and risk profiles of pain in persons with radiographic, symptomatic knee osteoarthritis: data from the osteoarthritis initiative

Abstract

Background Little is known about the temporal evolution of pain severity in persons with knee OA. We sought to describe the pain trajectory over 6 years in a cohort of subjects with radiographic, symptomatic knee OA. Methods We used data from the Osteoarthritis Initiative (OAI), a multi-center, longitudinal study of subjects with diagnosed radiographic evidence of knee OA. Pain was assessed at baseline and annually for 6 years. Our analysis cohort included subjects with symptomatic knee OA at baseline, defined as baseline Kellgren-Lawrence (KL) score ≥2 with WOMAC pain score >0. We used group-based trajectory modeling to identify distinct patterns of pain progression over 6-year follow-up. Factors examined included sex, race, education, comorbidities, age, body mass index (BMI), alignment, KL grade, and depression. Results We used data from 1,753 OAI participants with symptomatic knee OA. Mean baseline WOMAC pain score was 26.5 (0–100,100 = worst) with standard deviation 19. Group-based trajectory modeling identified 5 distinct pain trajectories; baseline pain scores for each ranged from 15 to 62. None of the trajectories exhibited substantial worsening. One fifth of subjects in the two trajectories with the greatest pain underwent total knee replacement over follow-up. Higher KL grade, obesity, depression, medical comorbidities, female sex, non-white race, lower education, and younger age were associated with trajectories characterized by greater pain. Conclusion We found that knee pain changes little, on average, over six years in most subjects. These observations suggest knee OA is characterized by persistent rather than inexorably worsening symptoms.

Defining knee pain trajectories in early symptomatic knee osteoarthritis in primary care: 5-year results from a nationwide prospective cohort study (CHECK)

“…[18][19][20] Using LCGA to define pain trajectories in knee OA is a relatively new technique and has only been applied by a few authors to date. [21][22][23] Holla and colleagues applied this technique on the same study population (CHECK), but used WOMAC physical function as the outcome variable; 22 they identified a three-group model and found similar associations to the study findings presented here. Collins and colleagues applied LCGA on a study population from the Osteoarthritis Initiative (OAI) and used WOMAC pain as the outcome measure; they identified five trajectories 21 and suggest knee OA is characterised by persistent, rather than severe, inevitable progression -this is in contrast with the findings presented here.…”

Is Weight Loss Associated with Less Progression of Changes in Knee Articular Cartilage among Obese and Overweight Patients as Assessed with MR Imaging over 48 Months? Data from the Osteoarthritis Initiative

“…Previous studies have found correlations between progression of changes in knee cartilage detected with magnetic resonance (MR) imaging and clinical symptoms and BMI (15,16); these correlations underline the fact that the potentially modifiable risk factor of obesity may contribute to the risk for osteoarthritis (17 (25,26), participants with cancer, cardiac failure, and/or other severe diseases developing during the study period were excluded. Furthermore, we excluded participants with missing clinical MR imaging studies at baseline (n = 24) or at 48 months (n = 384).…”

Obesity, Osteoarthritis and Pain

“…Collins et al [19] who examined 1753 osteoarthritis cases over an extended period found obese cases had greater pain than non obese cases. This pain generally remained unchanged over a 6 year period.…”