In the world of orthopaedics, hip replacement surgery is a common procedure that significantly improves the quality of life for those suffering from severe hip pain and mobility issues. As a specialist hip surgeon, I often face several questions:

“Which is better – a ceramic or metal hip replacement? Should it be cemented in or not ? I’ve heard about a robotic replacement .What is 3D planning and customised implants? ”

Here, I will guide you through the considerations and latest UK data relating to the above questions.

Understanding Hip Replacement Materials

Hip replacements typically involve an artificial joint (prosthesis) made up of a ball and socket, which replace your natural hip joint. The materials used for these prostheses are chosen for their strength, wear resistance, and biocompatibility and consist of between 3-4 parts. A Femoral stem and head ( bearing surface ) and an Acetabular cup and liner ( bearing surface ) . The Stem and the Cup are usually made of Titanium and are either cemented in or uncemented where there is a very tight fit and the implant has a coating on it which is like bone so will integrate with the body over time. Unfortunately cement will fail over a period of time so is less suitable for younger patients where we want the implant to last as long as possible.  Commonly used bearing surfaces include ceramic and metal for the heads, and ceramic, plastic ( and metal ) for the liners. So various combinations of bearing surfaces exist Ceramic on Ceramic (CoC), Ceramic on Plastic (CoP), Metal on Metal (MoM), Metal on Plastic (MoP)

Metal Hip Replacements

Metal-on-metal (MoM) hip replacements were popular in the UK during the late 1990s and early 2000s due to their durability and suitability for younger, more active patients. However, recent data suggest a higher failure rate in MoM implants compared to other materials, primarily due to concerns about metal ions released into the bloodstream from wear and tear and the bodies response creating pseudotumours which has resulted in this type of implant to fall out of favour and is very rarely used today. Metal on Plastic is still a very common option in the UK as it’s the cheapest option however this wears out the fastest and this will also cause the cement to fail too.

Ceramic Hip Replacements

Ceramic-on-Ceramic (CoC) and Ceramic on Plastic (CoP) hip replacements have been used since the 1970s and have evolved significantly over time. Current-generation ceramic bearings are incredibly hard and smooth, leading to very low wear rates. They do not release metal ions and are hence considered safer in that respect. The latest Ultra High molecular weight plastics have also shown to have great wear properties although not as good as ceramic but are cheaper to produce so have a role in limited healthcare economies.

Ceramic vs Metal: Which is Better?

Here are some key considerations:

  • Durability: Ceramic implants are less likely to wear down over time compared to metal, making them a good choice for younger, more active patients.
  • Noise: Some patients report a squeaking noise with ceramic implants. It can occur in extreme positions where there is a loss of fluid film lubrication. It is more likely if 3D planning is not undertaken
  • Fracture risk: Ceramic is more brittle than metal. Although the risk of fracture is very low with modern Delta ceramics.
  • Metal Ion Release: Metal bearings release metal ions into the bloodstream, and into the soft tissues potentially causing health problems. This is a concern with MoM implants.

Frequently Asked Questions

Q: How long do hip replacements last?

A: In the UK current statistics show about 85% of hip replacements last 20 years, and about 58% last 25 years. Please note the statistics are based on whether the implant has been replaced/revised so an elderly patient who cannot walk due to implant failure may not be fit enough for surgery and yet the implant is still classified as working!

Specific material longevity can vary, but ceramic implants often have less wear and can, therefore, potentially last longer.

The 3D customised implant system I use has a 98% 15 year survival and 95% 20 year survival in patients who had surgery before the age of 50 years who are classified as high demand (and fit enough for revision if not functioning). Again please note a high functioning patient could fall whilst doing their activity which means the implant has to be replaced now classifying the implant as a failure!

Q: Do all metal implants cause metal ion release?

A: No, this is primarily a concern with MoM implants. Metal-on-polyethene implants, where the socket is lined with a plastic (polyethene) insert, are currently the most commonly used type in the UK ( cost ) and have a lower risk of ion release but there is plastic degredation instead

Q: Can I choose the material for my hip replacement?

A: The choice of implant material depends on various factors, including your age, lifestyle, bone quality, and the surgeon’s experience. It’s important to discuss with your surgeon about the best choice for your circumstances.

In summary, hip replacements can significantly improve your quality of life if you have a hip joint affected by arthritis or injury. The decision between types is complex and should be made in consultation with your orthopaedic surgeon. As always, my goal is to provide you with the information you need to make the best decision for your health and lifestyle.