Q: How effective are surface implants in treating avascular necrosis? I underwent a renal transplant some time back.

A:Earlier surface replacement was not recommended in cases of avascular necrosis. However, now there are reports on surface replacement in avascular necrosis as well. In any case of avascular necrosis, there is always a risk that the AVN may progress after surface replacement has been done. This will cause early failure of the implant. Therefore, it is wiser to do surface replacement only after it is clear that there is no further progression of avascular necrosis. However, I notice from your case details that your avascular necrosis is after renal transplantation. Surface replacements are metal on metal prosthesis and these lead to high concentration of metal ions in the serum. This can be harmful for kidneys. Therefore, in kidney disease there is a tendency to avoid such prosthesis. I would not recommend this for you.