Fig. 3

Extension of surgical scope by one motion segment cranially. a-c T2-weighted magnetic resonance images preoperatively: a lumbar sagittal image and b axial lumbar image of L4/5 and c L5/S1. d Lateral radiographic image preoperatively and e postoperatively. The patient presented with chronic lumbar back pain and sciatic pain on the left side and a sensorimotor deficit of 4/5 on the Medical Research Council scale for muscle power for ankle dorsiflexion, plantarflexion, and toe extension. Advanced intervertebral disc degeneration was observed between L5 and S1 (Pfirrmann grade 4) and a median intervertebral disc protrusion at L5/S1. Mild facet joint degeneration was seen at L4/5 (Weishaupt grade 0 right and grade 1 left facet) and almost no facet joint degeneration at L5/S1 (Weishaupt grade 0 bilaterally). Recommendation before inpatient gradual diagnostics (IGD): Lumbar fusion at L5/S1 with transforaminal lumbar interbody fusion (TLIF). Results obtained during IGD: • bilateral facet joint infiltration of L5/S1: 70 % reduction of back pain. • epidural injection of L5/S1: 40 % improvement of sciatic pain. • bilateral facet joint infiltration of L4/5: 60 % reduction of back pain. Recommendation after IGD: lumbar fusion of L4-S1 with TLIF. At 1 year follow-up, the patient reported no pain