A method and apparatus for a
computer assisted surgery (CAS)
system using
alternative energy tissue and bone alteration technology. The CAS
system utilizes
alternative energy technology which is a directed to a
surgical instrument including an alteration or
cutting tip. The tip may be in contact with the tissue or bone, or, alternatively, the tip may be distant from the tissue or bone and the energy is projected to the desired
cut or alteration site. The CAS
system recognizes the location of the tip relative to a desired alteration location or area and de-energizes or varies the
energy level when the tip moves away from or out of the predetermined alteration location or path. The CAS system provides a method for altering or resecting bone, for example, in preparation for a prosthetic
implant, or a method for altering tissue, for example, cauterizing blood vessels or bonding ligaments to bones.