There are many problems with implants, of which the most obvious is reaction at the time of insertion. The majority of women who have silicone implants do not seem to react to the silicone - the immune system ignores it. However, for an unfortunate few the immune system is activated against the silicone. This can cause problems immediately after implantation when the body tries to get rid of the silicone. It does this by throwing up a fibrous capsule around the implant which then contracts, trying to squeeze the implant out. This is akin to the mechanism by which the body gets rid of any foreign body that gets into it, such as a thorn. In this event the implant goes hard and becomes painful. Surgeons often treat this by crushing the breast between their hands, either to rupture the implant or break the pseudo-capsule. However, this often creates just more problems. This technique is called external capsulotomy.
However, the long term effects are far more malign. This stems from the fact that silicone cannot be broken down by any enzyme system in the body, is engulfed by macrophages, carried to distant sites by embolisation and there it acts as an immune adjuvant, stimulating immune activity. This means that these patients may suffer from multisystem disease