Condition	Bone density	Erosions	Cysts	Joint space loss	Distribution	Bone production
Osteoarthritis	Normal overall	No, unless erosive osteoarthritis	Yes, subchondral	Nonuniform	Unilateral and/or bilateral; asymmetric	Yes; osteophytes; subchondral sclerosis
Rheumatoid arthritis	Decreased	Yes	Yes, synovial	Uniform	Bilateral; symmetric	No
Psoriatic arthritis	Normal	Yes	No	Yes	Bilateral; asymmetric	Yes
CPPD	Normal	No	Yes	Uniform	Bilateral	Yes; osteophytes; chondrocalcinosis; subchondral
Ankylosing spondylitis	Early—normal Late—decreased	Yes	No	Yes	Bilateral; symmetric	Yes
DISH	Normal	No	No	No	Sporadic	Flowing osteophytes; ossification of tendon, ligaments