Hip joint is a ball & socket joint.It is one of the most important joints as regards to weight bearing. Arthritis of the hip can lead to pain,difficulty in walking,sitting cross legged and sitting down in the floor. The most common causes of hip arthritis are #Avascular Necrosis #Osteoarthritis #Rheumatoid arthritis #Post traumatic arthritis #Infective arthritis The treatment of Hip Arthritis is Total Hip Replacement in which both the femoral head and Acetabular cup are replaced. Historically Hip Replacement was done with the help of 'cement' to fix the implants to the bone.Presently cementless,large diameter ceramic bearings are available which have a life span of more than 35 years. Considering the dramatic relief of pain and increase in mobility after Hip Replacement,it has been termed as 'THE SURGERY' of the 21st century.