Bone cysts containing silicone particles in bones adjacent to a carpal silastic implant.

Silastic implants for a wide variety of medical purposes are in current and frequent use worldwide. Only recently there have been reports of the migration of silicone to the surrounding tissues via lymphatics. In the present material of nine cases with carpal implants followed for more than two years, bone cysts developed in the surrounding bones on five occasions. The only cysts so far investigated thoroughly contained foreign body reaction, and silicone could be detected by electron probe microanalysis. A long-term follow-up is suggested whenever these implants are used.