Can you help me sort out all the different types of hip implants so I can decide which one is best for me?
Today's hip replacement patients are getting implants at an earlier age and wearing them out faster than ever before. Some of that wear and tear is because today's seniors are active Baby Boomers (born between 1946 and 1964).
Choosing the best implant for your activity, lifestyle, and physical size isn't as easy as it might seem. There are four basic implant designs. Let's start with the metal-on-polyethylene implant.
This is probably the most commonly used hip implant. The socket has a plastic liner. The round head of the femur that fits into the socket is metal with a metal stem that sets down inside the femoral shaft to hold it in place. It's the least costly of all the types available. It goes in easily and doesn't have to be set into the bone exactly-so to have a good result. But there are some problems. Most notably, it wears out faster than other types and isn't as stable. Older adults who are fairly inactive are the best candidates for the metal-on-polyethylene implant type.
Next comes the ceramic-on-polyethylene. The plastic liner is the same as the one used in the metal-on-polyethylene implant. The difference here is in the material used for the stem and femoral head: ceramic instead of metal. Ceramic is hard and scratch resistant. That's important in keeping wear debris out of the joint. There is a risk that the ceramic will crack or fracture and it doesn't hold up as good as the ceramic-on-ceramic implants.
Those ceramic-on-ceramic surfaces have the lowest friction, roughness, and biologic reactivity. The surface is resistant to wear and tear so this type is used most often for younger, more active patients. And, of course, it can be used with anyone who has metal sensitivities. With both surfaces made of ceramic, there's an even greater risk of implant fracture. Pieces of the ceramic can get imbedded in the joint capsule making it difficult to remove the broken implant. The two other disadvantages of ceramic-on-ceramic are the cost (most expensive) and the fact that these implants can squeak loudly enough to be heard.
The last choice with an equal number of pros and cons is the metal-on-metal implant. This type of implant does create tiny flecks of metal that enter the blood, urine, and organs and to which patients may react. This type of implant is not advised for women who can get pregnant or anyone with kidney disease. The implant is the most stable and gives more athletic adults greater freedom to run, jump, and participate in sports activities.
There isn't a perfect implant that can be used for everyone. Each type has its own advantages and disadvantages. The surgeon tries to make the best choice for each individual based on age, size, activity level, and sensitivity to materials (ceramic, plastic, metal).
Patients like you often want to participate in that selection process. Hopefully, this information will help you understand your surgeon's recommendations and come to a mutually agreeable selection.
Karim Elsharkawy, et al. Evolution of Bearing Surfaces in Total Hip Arthroplasty: A Review. In Current Orthopaedic Practice. March/April 2010. Vol. 21. No. 2. Pp. 198-208.
*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.