title: GENESIS OF PAIN IN ARTHROSIS.
abstract: Advances in knowledge regarding the pathophysiology of pain among patients with knee osteoarthritis suggest that the central nervous system is involved as a source that maintains and amplifies the painful condition such that it is refractory to conventional orthopedic and rheumatological treatment. Initially, hyperalgesia is observed only at the affected site. However, when the pain becomes refractory, peripheral and central sensitization mechanisms contribute towards maintaining and amplifying the painful conditions, regardless of the peripheral process that originated the pain. At this stage, even removal of the etiological agent may no longer be enough to relieve the painful symptoms. It then becomes necessary to envisage that other factors, distant from the affected joint, may be responsible for the disabling painful condition in such patients. At present, osteoarthrosis does not have any known cure, and the aim of treatment is to lessen the pain while improving function and health-related quality of life, and whenever possible, to minimize the toxicity of the therapy. In the light of emerging evidence suggesting that the central nervous system has a role in the physiopathology of pain in patients with knee arthrosis, the central nervous system should be taken into consideration as a therapeutic target, instead of only administering local treatment using ordinary analgesics, anti-inflammatory drugs and non-pharmacological measures. Thus, methods that modulate the spinal cord and cerebral cortex, including the use of antidepressants, may have a role in managing these patients.
authors.affiliation: Titular Professor of the Department of Orthopedics and Traumatology, School of Medicine, University of São Paulo.
authors.forename: Gilberto Luis
authors.initials: GL
authors.lastname: Camanho
authors.affiliation: Collaborating Professor in the School of Medicine, University of São Paulo.
authors.forename: Marta
authors.initials: M
authors.lastname: Imamura
authors.affiliation: Head of the Sensory-Motor Interaction Center, Department of Health Sciences and Technology, University of Aalborg, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
keywords: Arthrosis; Knee/physiopathology; Pain/therapy