Clinical and radiologic 2-4-year results of transforaminal lumbar interbody fusion in degenerative and isthmic spondylolisthesis grades 1 and 2. - Lauber S; Schulte TL; Liljenqvist U; Halm H; Hackenberg L; Lauber, Sebastian; Schulte, Tobias Ludger; Liljenqvist, Ulf; Halm, Henry; Hackenberg, Lars (Spine (03622436), 2006)