Components of Hip Replacement
The modern (modular) Total Hip Replacement has 3 components: the Femoral Stem which is anchored in the Femur shaft (thigh bone), Femoral Head which is fixed on to the top of the Femoral Stem and the Cup which is fixed into the Acetabular socket.
The Femoral Stem is made of metal (Alloy of steel), the Femoral Head is made of metal or ceramic and the Cup made of either plastic (Ultra High Density Polyethylene), metal or ceramic. Thus there are various options: the conventional metal-on-plastic (metallic head on plastic cup), metal-on-metal (metallic head on metallic cup), ceramic-on-metal (ceramic head on metallic cup) and ceramic-on-ceramic (ceramic head on ceramic cup).
What are the different types of Hip Replacement?
Hip Replacements can be classified as Total Hip Replacement when both the Ball (Head of Femur) and the Socket (Acetabulum) are replaced. When only the Ball (Femur Head) is replaced it is called Partial Hip Replacement (Hemiarthroplasty). Hip Resurfacing refers to a procedure wherein the Femur Head is preserved and only the surface of the head is shaved of and replaced. Bipolar Hip replacement is a prosthesis wherein the metallic Cup is fixed on to the Femoral component and is free to move in the acetabular socket. This type of implant is best suited for patients with fractured hips.
Hip Replacements are also classified as Cemented when bone cement (Polymethyl methacrylate) is used to anchor the implants to bone or Uncemented when the implants are directly impacted onto raw bone. When one component is cemented and the other fixed without cement it is called Hybrid Hip.
