This invention relates to a surgery control tool: being no patient implant, comprising: an elongated body (7, 37) having the shape and the size of a spinal correction rod, end contact parts (9, 39) being able to contact a patient implanted spinal correction rod implant (12, 13), spacers (8, 38) extending from said elongated body (7, 37) towards said end contact parts (9, 39).