Does Rheumatoid Arthritis affect larger joints?
RA is not uncommon in the knee and hip joints. When present, typical findings include relatively symmetric joint space narrowing with a disproportionate lack of productive bony changes. Protrusio acetabuli is a finding in the hip joint that can be seen in RA (among other etiologies) where there is intrapelvic displacement of the medial wall of the acetabulum. The shoulder joint may be affected by erosive changes at the glenohumeral joint, distal clavicular osteolysis, and a “high-riding” humeral head with a decreased acromiohumeral interval.