[Arthritis from a clinical viewpoint]

Arthrosis is a collective term the elucidation of which is of decisive importance for the clinical practitioner. The main definition (pathologic/anatomic, radiologic and clinical arthrosis) as well as the pertaining sub-definitions are presented and explained. Both condition definitions latent (dormant) and manifest (active and/or decompensated arthrosis) are clinically relevant. While the cause of primary arthrosis is--presently--still mostly unknown, causes of secondary arthrosis can be defined. Secondary arthrosis is the consequence of a pre-arthrosis. This definition nowadays comprises all kinds of joint lesions (not only of mechanical or traumatic kind) causing an irreversible lesion of the joint organs. Pains of manifest arthrosis are either due to activation (reactive secondary synovitis) or to decompensation (periarthropathy and painful muscular irritations as well as consecutive functional disorders). The distinction is decisive for applying therapeutic means. The clinically subjective and objective symptoms of arthrosis and considerations regarding differential diagnosis are described in detail.