Lumbar posterolateral fusion alone or with transpedicular instrumentation in L4-L5 degenerative spondylolisthesis

We retrospectively reviewed 57 patients with L4-L5 degenerative spondylolis thesis (L4-L5 DS) who underwent posterior decompression and posterolateral fusion of L4-L5 without (Group A) or with (Group B) transpedicular screw in strumentation at least 2 years earlier. The clinical results and fusion rat e were similar between Groups A and B, that is. a 72.4% satisfactory outcom e with a fusion rate of 82.8% in Group A versus 82.1% satisfactory outcome with a 92.8% fusion rate in Group B. Screw instrumentation reduced postoper ative low back pain and resulted in a lordotic slip angle of L4-L5. However , in patients with radiologically excessive segmental motion showing a tran slational motion of 3 mm or more, flexion angulation of -5 degrees or less, and a slip angle of -5 degrees or less at the site of spondylolisthesis (L 4-L5), the kyphotic slip angle (L4-L5) tended to increase after surgery. In the future, in patients with radiologically excessive segmental motion, th is point should be considered, and surgical techniques should be evaluated. Our results suggest that the validity of the general addition of screw ins trumentation to L4-L5 fusion for L4-L5 degenerative spondylolisthesis is lo w.