screwdriver for head of band hook

English to German Medical Medical: Instruments Surgery on spine

This is a list with instruments and ancillaries, so no context which I could provide or would have to myself - not even pictures. Thanks for any idea whether this refers to head of "band hook" or hook for "head of band" (makes less sense to me). I know there are many different kinds of hooks for spine surgery. So, perhaps someone of you read about this one before. Google ha not enlightened me. Thanks for your response. Br, Eveline