Metal on Metal Hip Replacements
If you are considering having hip surgery, you should look into all of the various types of replacements that are available. It is best to have a discussion with your doctor about any issues you may have and any questions that may arise as you learn about the different ways to replace the hip with surgery. Each type of implant has its own benefits and risks. Overall, metal-on-metal hip implants have been shown to provide high implant success with little to no need to remove the implant and put another in its place. Hip resurfacing is intended to be a bone preserving procedure, though all artificial hip implants carry risks including wear of the material.
In Metal on Metal hip implants, the metal ball and the metal cup slide against each other during walking or running activities. Metal can also be released from other parts of the implant where two implant components connect. Metal release will cause some tiny metal particles to wear off of the device into the space around the implant. Wear and corrosion at the connection between the metal ball and taper of the stem may also occur. Because of metal’s durability, metal-on-metal devices are expected to last longer than other hip implants. In addition, the ball in a metal-on-metal device is larger, making the hip joint more stable and less likely to dislocate.
Orthopedic surgeons take several precautions before and during hip replacement surgery to try to optimize the way in which the ball and socket rub against each other so that fewer wear particles are produced. However, there is no way to fully avoid the production of some metal particles. Different people will react to these metal particles in different ways. At this time, it is not possible to predict who will experience a reaction, what type of reaction they might have, when the reaction will occur, or how severe the reaction will be. This is why each patient must provide a full medical history and consult frequently with their doctor regarding the hip surgery as this will ensure a customized surgical plan and a more accurate, individualized course of recovery to ensure better, more successful results.
Metal-on-Metal hip implants were designed to offer the following benefits:
- Less device material wear is generated when the ball and socket rub against each other in comparison to other hip implants
- Decreased chance of dislocation when the ball of the thighbone (femur) slips out of its socket in the hip bone (pelvis)
- Decreased chance of device fracture
Your orthopedic surgeon should assess your individual needs and will avoid using Metal-on-Metal hip implants for your replacement if the risks prove to outweigh the benefits.
Should I consider a different option than Metal-on-Metal?
Each type of hip implant has its own set of benefits and risks. Metal-on-metal hip implants are not for everyone. You should discuss your situation with your surgeon to determine whether you are a candidate or not. In general, metal-on-metal hip systems are not meant to be implanted in
- Who have kidney problems
- Who have a known allergy or sensitivity to metals
- Who have a suppressed immune system
- Who are currently receiving high doses of corticosteroids such as prednisone
- Who are women of childbearing age
Again, every hip implant has a distinct set of benefits and risks and should be considered uniquely. The key design features of each implant including size, material, and dimensions make each system unique. In addition, the same hip system will have different outcomes in different patients, again making it essential that you stay in constant communication with your doctor to ensure the best results possible for you as a patient.