Advice to patients concerning the ASR
I suggest a few points that, I think, everyone can agree to (for any hip, including an ASR):
1. If you have pain or are in any way concerned – go see your surgeon.
2. There are some screening tests. Based on current experience, if blood (or serum) ion levels of Cr and Co are <5ppb, the likelihood a problem with the implant is low. If the level of either is >10ppb, the likelihood of a problem with the implant is increased. In either event, the next step would be an imaging study (ultrasound or MRI) to look for a fluid collection, or a cystic or solid mass – as evidence of an adverse local tissue response.
3. An aspiration of the joint may be appropriate a) to exclude infection as a cause of the joint dysfunction and b) the characteristics of the fluid may help in the differential diagnosis of a problem related to the metal-metal bearing.
I think that the first point is the most important. If you are concerned, go see your surgeon.
Thomas P. Schmalzried, M.D.