It most commonly affects older adults (> 70 years), with most patients female.
Changes to the joint include:
(1) complete tear of the rotator cuff
(2) degenerative osteoarthritis
(3) noninflammatory joint effusion with calcium hydroxyapatite and calcium pyrophosphate dihydrate (CPPD) crystals
(4) synovial lining cell hyperplasia
(5) destruction of cartilage and subchondral bone
(6) multiple osteochondral loose bodies
Over time the patient develops progressive functional impairment.
The full extent of joint damage can best assessed using MRI.
Laboratory findings:
(1) elevated CRP and ESR
(2) negative rheumatoid factor
(3) negative anti-citrullinated peptide antibody
(4) negative cultures
(5) clumps calcium hydroxyapatite crystals seen on an alizarin red S stain and/or CPPD crystals
A similar process may affect other joints such as the elbow or knee.
