Greater baseline knee pain, along with fluctuating, persistent knee pain over 1 year, is predictive of accelerated cartilage volume loss and an increased risk for incident, progressive radiographic osteoarthritis (OA) over 4 years, according to the results of a prospective cohort study published in Arthritis Research & Therapy.
The investigators sought to explore whether knee pain over a 1-year period predicted cartilage volume loss, incidence, and progression of radiographic OA over a 4-year period. Participants from the Osteoarthritis Initiative with no radiographic OA (Kellgren-Lawrence grade ≤1; n=2120) and with radiographic OA (Kellgren-Lawrence grade ≥2; n=2249) were assessed. Knee pain was evaluated at baseline and at 1 year using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Knee pain was categorized as follows: no pain (WOMAC pain <5 at baseline and at 1 year), fluctuating pain (WOMAC pain ≥5 at either time point), and persistent pain (WOMAC pain ≥5 at both time points). Magnetic resonance imaging and radiographs at baseline and at 4 years were used to evaluate cartilage volume, incidence of radiographic OA, and progression of radiographic OA.
In both nonradiographic OA and radiographic OA groups, greater baseline WOMAC knee pain scores were significantly associated with increased medial and lateral cartilage volume loss (P ≤.001), incidence of radiographic OA (odds ratio [OR], 1.07; 95% CI, 1.01-1.13), and progression of radiographic OA (OR, 1.07; 95% CI, 1.03-1.10).
Moreover, participants with nonradiographic OA and radiographic OA with fluctuating and persistent knee pain experienced increased cartilage volume loss vs those with no knee pain (P for trend ≤.01). Those with nonradiographic OA and fluctuating knee pain had an increased risk for incident radiographic OA (OR, 1.62; 95% CI, 1.04-2.54). In those with radiographic OA, the risk for progressive radiographic OA increased in those with persistent knee pain (OR, 1.82; 95% CI, 1.28-2.60).
The investigators concluded that early management of knee pain and the control of knee pain over time by targeting the responsible underlying mechanisms may be key to preserving knee structure and reducing the burden of knee OA.
Wang Y, Teichtahl AJ, Abram F, et al. Knee pain as a predictor of structural progression over 4 years: data from the Osteoarthritis Initiative, a prospective cohort study. Arthritis Res Ther. 2018;20(1):250.