A mono-arthritis of the knee due to synovial metaplasia similar to synovial osteochondromatosis.
20-40 age group
Same sex distribution
Theories include repeated trauma, a viral aetiology, a lipid disturbance or a histolytic response to an unknown stimulus.
The plain film may suggest synovial disease although these can be subtle
Bone changes are present in 90% of patients with PVNS.
Preservation of bone density until relatively late.
Cartilage loss is also late
Traction spurs and osteophytes are uncommon.
MRI is the main stay for diagnosis of PVNS.
Haemosiderin deposition shows as low signal material on T2
Prominent blooming on T2* also helpful
