Hip replacement surgery is a procedure wherein the damaged or diseased part of the hip joint is operated on by the surgeon. To understand better, let us understand the structure of a hip. The Hip joint is much like a ball and a socket joint. The top of thigh bone contains the ball part of the hip joint. Our leg is able to move in all possible directions because of the ball in the socket. The socket is situated as a part of the pelvis. For smooth movement, as in the case of a normal hip, there has to be smooth cartilage covering the end of the thighbone (ball) and pelvis (socket).

However,  in the case of a dysfunctional hip, smooth movement is restricted by the worn cartilages.  The Bone gets damaged, uneven and rough as it gets rubbed against each other whenever there is hip movement. This eventually leads to pain. When the situation goes beyond the scope of oral medication, Hip replacement surgery is suggested. It is performed either as a Hemi replacement or as a total replacement (arthroplasty).  In total hip replacement surgery, the worn-out socket as well as the ball (femur head) is completely changed and replaced with polythene  (plastic) or ceramic one (for the socket), and metal/ceramic for the ball (femur head).

There are multiple ways of attaching the implant to the bone. The implant can be attached to the bone using cement during a cemented hip replacement, whereas in the case of a non-cemented replacement procedure, the bone grows on and into the surface of the implant. Types of Bearing surfaces could include

1. Ceramic on ceramic 
2. Metal on polythene (plastic)
3. Ceramic on poly

Out of these the most commonly used bearing surface is metal with highly cross-linked polyethene and ceramic on highly cross-linked polyethene.