Possible Clues:

• Cut skin cell evenly with this?
• Start operating with this set of notes covering page 50
• Various places left for one useful in the theatre
• It's used for opening act in theatre
• It may cut the top of head — well, not the sides
• Surgeon's principal vocation will involve exercises – with this?
• Make a quick profit with the Spanish knife
• Medical knife
• Small knife
• Surgeon's need