Here’s How to Predict OA Pain Trajectory

A new study, with more than a 10-year follow-up of nearly 1,000 patients, was able to identify how osteoarthritic knee pain moves along three trajectories in older patients.

The study,“Predictors of pain severity trajectory in older adults: a 10.7-year follow-up study,” was published in December 2018 edition of Osteoarthritis and Cartilage.

Co-author Feng Pan, Ph.D. a research fellow at the Menzies Institute for Medical Researchat the University of Tasmania in Australia, described his study to OTW, “Knee pain is the most prominent symptoms of knee osteoarthritis (OA). It is also a main reason for people seeking joint replacement. Despite this, the causes of knee pain are poorly understood. Therapy will only improve if we understand this better.”

The authors wrote, “963 participants (aged 50-80 years) from a population-based cohort had baseline demographic, psychological, lifestyle and comorbidities data collected. T1-and T2-weighted magnetic resonance imaging (MRI) of the right knee was performed to measure knee structural pathology-cartilage defects, bone marrow lesions (BMLs) and effusion-synovitis…”

Dr. Pan explained what he and his colleagues learned from the study. “We identified three distinct trajectories over time. Remarkably, structural factors (cartilage defects, bone marrow lesions, effusion-synovitis), obesity education level, unemployment and the presence of emotional problems are associated with more severe pain trajectories, suggesting that pain course is determined by an integrated mix of all these factors. We already know that structural damage is a major driver in the development and maintenance of pain severity but less is known about the other factors.”

“We found that participants within the ‘Mild pain’ and ‘Moderate pain’ trajectory were more likely to have a greater BMI [body mass index], be less physically active, have more emotional problems, be unemployed, have a lower education level, have more comorbidities and a greater number of painful sites than those within the ‘Minimal pain’ trajectory.”

“Those in the same pain trajectory group are individuals following similar courses of pain evolution over time. The pain experience is both complex and individual in nature, suggesting the clinician should target treatments according to which of these factors predominate in the individual.”

“These trajectories potentially represent distinct subgroups and may be clinically useful for the accurate classification of patients with knee pain, particularly for OA patients.”