Information in this section pertains to all global PEN® partners except where country flags are
visible. Click on the flag(s) for country-specific information. If a country flag is not listed, there is
no information specific to that country.
Disease Etiology
Osteoarthritis (OA) affects all parts of the joint (1). Etiology is multifactorial, typically involving the remodelling of adjacent bone and the progressive loss of articular cartilage resulting from proteolytic enzymes (1). Subchondral bone marrow lesions hold a key role in OA and are associated with pain (2). OA is an inflammatory disorder with low grade synovial inflammation and cytokines contributing to cartilage damage (1). Although OA can affect any joint, knee OA