Osteoarthritis is associated with all of the following except -
Decreased joint space
Subchondral sclerosis
Osteophyte formation
Ca++deposition in joint space
Radiological features of osteoarthritis 

The diagnosis of OA can be made on x-ray which shows:-

i) Narrowing of joint space → Earliest manifestation                                    
ii) Spurring' or 'lipping' of the joint from the formation of osteophytes  
iii) Loose bodies
iv) Subchondral sclerosis
v) Subchondral cyst
vi) Deformity of the joint