A surgical instrument for perforating dense tissue of a human or animal body and for injecting a pharmaceutical product behind the tissue. The instrument includes a hand-piece with a housing for a pharmaceutical product container. The hand-piece has two opposite ends, one of which includes an axial throughway leading into the housing for passing a perforator injection needle inserted in the container. The other end is used to drive the container and needle in rotation. The surgical instrument further includes a member that, during perforation, can exert pressure on the pharmaceutical product in the container inserted in the housing to prevent perforation debris from entering into the needle.