Types/makes
The image below shows the list that I made over the types and makes hip resurfacing prostheses found in the world. We patients should be aware of what the surgeon intends to give us exactly, so that we can have a say in the matter and make sure that this is really what is wished and needed. A second or third opinion from independent (specialized resurfacing) surgeons should be considered if in doubt.
Apart from the fact that prostheses from some makes may be surrounded by problems, we patients should also be aware of the so-called hemi-arthroplasty method. With hemi-arthroplasty the joint only receives a prosthesis of some kind on the limb but a mating articulation cup is NOT placed in the body. Hemi-arthroplasty can be applied in different joints of the body, but just as with resurfacing it is not limited to the hip only.
With hemi-arthroplasty the orthopaedic surgeon has the choice between shafted prostheses and resurfacing prostheses of differing types.
Surgeons use hemi-arthroplasty often in cases with avascular necrosis and if there is still enough cartilage left in the joint. At first sight this can appear an attractive and less intrusive method, since it does only modify the part of the joint that is affected by disease. But today nearly every orthopaedic surgeon agrees that hemi-arthroplasty does not live up to the expectancies. The artificial head on the limb is not compatible with the joint’s cartilage, wearing the remaining cartilage down at high speed.
Hemi-arthroplasty is mainly used on younger patients, but it is just those patients that have active lifestyles and will wear out their remaining cartilage the quickest. A new operation to give the patient a matching cup in the joint will many times come quicker than anticipated, one year or a couple of years after the first operation is no exception. Patients should also know that some prostheses that only exist as hemi device never can receive a matching cup, forcing the complete revision of the joint to traditional total arthroplasty, for which the femoral neck is removed.
Even with hemi-arthroplasty, let’s say of the hip joint, the patient should stay awake and not get lured into accepting a traditional type of prosthesis for which the femoral neck has to be sawn off and tossed away. At least this should never be considered if there is not a very serious reason why the natural femoral neck can’t be retained. With even the slightest doubt this should first be confirmed by a number of other specialized hip resurfacing surgeons, only they value the femoral neck for what it is really worth!
Even if hemi-arthroplasty itself can be a questionable method, when it is still going to be used then preferably only with the femoral cap from a well known hip resurfacing device. That way the procedure is more bone-sparing and given a higher guarantee that it can be revised to a complete hip resurfacing if required at a later point in time. For that reason a hemi should not be placed by a surgeon who normally doesn’t place resurfacings but only by one with high resurfacing experience. Fitting it under the correct angles ensures its future usefulness when coupled with a cup.
If a surgeon says that a hemi-resurfacing is not possible then in that case a hemi-BMHR should be seriously considered as the next best option before taking the drastic step to a hemi that uses a long shafted prosthesis (for which the femoral neck needs sawing off).
Last but not least, instead of using hemi-arthroplasty in any of the above forms, it is generally regarded much wiser to limit the amount of operations by directly placing a complete resurfacing prosthesis, including the cup. This lowers the amount of tissue damage, minimizes the total rehabilitation time and chance on infections and also presses the overall costs.
Please review the list above, you are welcome with any questions or additions.
2010-11-27