An instrument of an instrument set is used to insert an implant into a disc space. The implant comprises a first cage and a second cage and the instrument comprises a distal end configured to push the cage first inserted into the disc space laterally in its proper anatomical location. Said distal end of the instrument has a tip, which is curved and has a curved inner side configured to contact an outer curved side of the first cage. The instrument set allows the insertion of two cages through a relatively small incision in the interdisc space in a simple jet safe procedure.