The axillary view provides the best image to look for joint-space narrowing and helps rule out dislocations.
[aafp.org]
A true anteroposterior (AP) view is necessary to gauge the degree of joint space narrowing.
[reference.medscape.com]
Early in the disease process, radiographic evidence of degenerative joint disease may include joint-space narrowing (mild), osteophytes (small), subchondral sclerosis, cysts
[aafp.org]