This perspective article puts forth a conceptual model for the pain experience for individuals diagnosed with knee osteoarthritis (OA). Pain in knee OA is likely a heterogeneous, multi-factorial phenomenon that involves-not only the OA disease process-but elements unique to patient psychology and pain neurophysiology. The relevant contributions to the pain experience for any individual patient are still difficult, if not impossible, to definitively determine, and the rationale for many clinical treatment decisions arises primarily from a mechanistic understanding of OA pathophysiology. The Osteoarthritis Research Society International (OARSI) recently identified “phenotyping” of OA pain as a research priority, to “better target pain therapies to individual patients.” The authors propose that contributions from the following three domains: 1) knee pathology, 2) psychological distress and 3) pain neurophysiology, ought to be considered equally important in future efforts to understand pain phenotypes in knee OA.
Ultimately, characterization of pain phenotypes could assist in the understanding of the pain experience and the development of interventions specific to pain for individual patients.