Hip
Trauma
- fracture, OCD
- ligamentous injury / ACL
- meniscal injury
- tendonitis / patella
- bursitis
- apophysitis / OSD
- PJF tilt / instability / chondromalacia
Infection
Tumour
Inflammatory
- rheumatoid
- seronegative
- CT disorder
Synovial
- PVNS, chondromatosis
Congenital
- discoid meniscus
- plica