Hyperexcitability of the central nervous system (CNS) has been suggested to play an important role in the chronic pain experienced by osteoarthritis (OA) patients. A systematic review following PRISMA guidelines was performed to evaluate the existing evidence from the literature related to the presence of central sensitization (CS) in patients with OA.Electronic databases PubMed and Web of Science were searched to identify relevant articles using pre-defined keywords regarding CS and OA. Full-text clinical reports addressing studies of CS in human adults with chronic complaints due to osteoarthritis were included and screened for methodological quality by two independent reviewers. From the 40 articles that were initially eligible for methodological quality assessment, 36 articles achieved sufficient scores and therefore were discussed. The majority of these studies were case-control studies and addressed OA of the knee joint. Different subjective and objective parameters considered manifestations of CS, which have been previously reported in other chronic pain conditions such as whiplash or rheumatoid arthritis, were established in subjects with OA pain. Overall results suggest that, although peripheral mechanisms are involved in OA pain, hypersensitivity of the CNS plays a significant role in a subgroup of subjects within this population. Although the majority of the literature provides evidence for the presence of CS in chronic OA pain, clinical identification and treatment of CS in OA is still in its infancy, and future studies with good methodological quality are necessary.

Central sensitization provides an evidence-based explanation for many cases of 'unexplained' chronic musculoskeletal pain. Prior to commencing rehabilitation in such cases, it is crucial to change maladaptive illness perceptions, to alter maladaptive pain cognitions and to reconceptualise pain. This can be accomplished by patient education about central sensitization and its role in chronic pain, a strategy known as pain physiology education. Pain physiology education is indicated when: 1) the clinical picture is characterized and dominated by central sensitization; and 2) maladaptive illness perceptions are present. Both are prerequisites for commencing pain physiology education. Face-to-face sessions of pain physiology education, in conjunction with written educational material, are effective for changing pain cognitions and improving health status in patients with various chronic musculoskeletal pain disorders. These include patients with chronic low back pain, chronic whiplash, fibromyalgia and chronic fatigue syndrome. After biopsychosocial assessment pain physiology education comprises of a first face-to-face session explaining basic pain physiology and contrasting acute nociception versus chronic pain (Session 1). Written information about pain physiology should be provided as homework in between session 1 and 2. The second session can be used to correct misunderstandings, and to facilitate the transition from knowledge to adaptive pain coping during daily life. Pain physiology education is a continuous process initiated during the educational sessions and continued within both the active treatment and during the longer term rehabilitation program.