[Arthritis of the shoulder]

Diagnosis of shoulder arthritis should situate the precise location (glenohumeral, acromioclavicular, scapulothoracic) and rapidly determine the cause in order to eliminate the possibility of septic arthritis which requires urgent treatment. Good knowledge of shoulder symptomatology is essential. When there is joint effusion, the fluid should be sampled for rapid analysis (cells, crystals, germs), and the work-up for diagnosis must include clinical and laboratory analyses as well as imaging. Causes are especially microcrystallin arthritis (hydroxyapatite rheumatism, chondrocalcinosis, etc.) and inflammatory rheumatism (rheumatoid arthritis, ankylosis spondylitis, etc.). Septic arthritis is much less common but more rapidly destructive, which justifies their consideration whenever suspected. Treatment should be rapidly initiated in acute, particularly septic forms. In other forms, diagnosis guides treatment. Steps should be taken rapidly, both medically and sometimes surgically, to avoid destructive articular and periarticular lesions (rotator cuff).