Indications to do a Total Hip replacement:
Arthritis-may be osteoarthritis, rheumatoid arthritis, other inflammatory arthritis associated with Cohns disease, ulcerative colitis, psoriasis etc
Avascular necrosis of head of femur
Developmental disorders- DDH
Perthes disease with secondary osteoarthritis
Slipped upper femoral epiphysis with secondary osteoarthritis
Hip fractures