According to Arthritis Research UK, the goal of hip replacement surgery is to replace damaged hip surfaces with prosthetic implants. This type of surgery may be carried out in people suffering from conditions such as osteoarthritis and rheumatoid arthritis. However, it may also be used in patients who have suffered a hip fracture. The hip joints need to be able to bear weight comfortably. As such, implants are made of hard-wearing materials such as metal, ceramic, or plastic.
Metal
Metal may be used for both the ball and socket components of the hip joint. An implant in which both the ball and socket are made of metal is known as metal-on-metal hip replacement. According to an article published in "The Journal of Arthoplasty," metal implants allow a good range of movement, and have low dislocation rates. However, there have been some concerns associated with the use of metal implants. A 2010 article published in the "Telegraph" newspaper reported that metal hip replacements could increase the risk of developing non-cancerous tumors and may also lead to tissue damage. Doctors believe the damage is being caused by debris produced by friction between the metal plates at the hip joint.
Ceramic
Ceramic has been in hip replacement for more than 30 years in Europe but has only been approved in the United States since 2003. Ceramic may be used for both the ball and socket components of the hip joint, or may be mixed with another material. For example, some hip implants consist of a ceramic ball and a polyethylene-lined socket. According to bonesmart.org, ceramic is the hardest implant material and has a low wear rate which makes it particularly suitable for young and active people.
Plastic
A type of plastic called polyethylene may be used for the socket component of hip replacement. This is usually combined with a metal ball. However, polyethylene is often associated with high rates of wear. As such, newer types of plastics are being developed for use in hip replacement surgery. A 2009 research paper published in "The Journal of Bone and Joint Surgery," reports on the use of a highly cross-linked polyethylene which has been shown to have a lower wear rate than conventional polyethylene.
References
- Arthritis Research UK: Hip surgery
- "The Journal of Arthoplasty": Metal-on-metal hip resurfacing: advantages and disadvantages
- Telegraph: Metal hip replacements could cause tumours, doctors warn
- Bonesmart.org: The Basics of Total Hip Replacement Surgery
- The Journal of Bone and Joint Surgery: Wear Rate of Highly Cross-Linked Polyethylene in Total Hip Arthroplasty
