An instrument for measuring a depth of a hole in bone can comprise an instrument body having a cannulated sleeve that extends between a first end and a second end. A first reference portion can be disposed at the first end and a second reference portion can be disposed at the second end. A probe can selectively and alternatively translate in first and second opposite directions through the cannulated sleeve between a first measuring position and a second measuring position. The probe extends outwardly a distance spaced from the first reference portion in the first measuring position and extends outwardly a distance spaced from the second reference portion in the second measuring position.