Fig. 2

Confirmation of an uncertain indication for surgery. 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 and sciatic pain on the right side. Moderate intervertebral disc degeneration was observed between L5 and S1 (Pfirrmann grade 3-4 [13]) and a secondary neuroforaminal stenosis on the right side. Moderate facet joint degeneration was seen at L4/5 (Weishaupt [14, 15] grade 1 right and grade 2 left facet) and L5/S1 (Weishaupt grade 1 right, grade 2 left facet). Recommendation before inpatient gradual diagnostics (IGD): lumbar fusion of L5/S1 with transforaminal lumbar interbody fusion (TLIF). Results obtained during IGD: • epidural injection of L5/S1: 20 % sciatic pain relief. • bilateral facet joint infiltration of L5/S1: 80 % back pain relief. • bilateral sacroiliac joint infiltration: 10 % back pain relief. • iliac crest infiltration at muscular insertion of erector spinae: 80 % pain relief. Recommendation after IGD: lumbar fusion of L5/S1 with TLIF. At 1 year follow-up, the patient reported no pain