For some patients with knee osteoarthritis, pain signals are centralized and become more intense, rather than waning with time. Is this caused by continuing injury to the damaged knee, or is inflammation more prominent?
In this video, researcher Tuhina Neogi of Boston University School of Medicine describes research presented at the 2014 annual meeting of the American College of Rheumatology that addressed this question by assessing specific signs of inflammation (synovitis and effusion on MRI) and noninflammatory tissue injury (bone marrow lesions) with relation to the development of central sensitization of pain.
An Associate Professor at Boston University School of Medicine, Dr. Neogi studies the epidemiology of rheumatic disease.
You've been looking at the causes of sensitization of knee osteoarthritis pain. How do you define sensitization?
Can you tell us about the study that you presented at the ACR?
We've heard a lot lately about the fact that rheumatologists are able to address inflammation but they're not so able to address pain. Do you think your findings have any practical implications with regard to what rheumatologists are or are not able to do?
If your listeners want to look for the next paper that carries this research forward, what might its title be? What should they be looking for?
We and others have demonstrated that sensitization is associated with increased pain severity ... and change in pain over time. But what we didn't know is what causes sensitization in knee OA.
Inflammation likely contributes to sensitization in knee osteoarthritis, whereas bone marrow lesions do not appear to do so. Therefore, bone marrow lesions likely contribute to pain through other mechanisms.
We need to do some more studies to see if intervening early on these parameters of inflammation has an effect.
I think overall the take-home message for clinicians is that pain is a multifactorial symptom and we need to move more towards mechanism-based pain management that's not a one-size-fits-all for everyone. ... We cannot just say "This is the first step. This is the second step." It has to become more personalized.
Neogi T, Nevitt MC, Scholz J, et al. Effect of Synovitis, Effusion and Bone Marrow Lesions on Development of Sensitization in Knee OA: The Multicenter Osteoarthritis Study ACR Abstract #2783, 2014 66:S1306. Abstract Supplement, 2014 ACR/ARHP Annual Meeting