Decompression alone versusdecompression with instrumental fusionthe NORDSTEN degenerativespondylolisthesis trial (NORDSTEN-DS);study protocol for a randomized controlledtrial Austevoll, Ivar Magne, Hermansen, Erland, Fagerland, Morten, Rekeland, Frode, Solberg, Tore, Storheim, Kjersti, Brox, Jens Ivar, Lønne, Greger, Indrekvam, Kari, Aaen, Jørn, Grundnes, Oliver, Hellum, Christian (2018-12-18)