Fig. 3

A 59-year-old gentleman underwent L4/5 TLIF with cage subsidence. Disc height was 6.2 mm preoperatively (A), 10.8 mm immediately after surgery (B), and 7.5 mm at 16 months’ follow-up (C). Pre-operative HU were 112 for HU1, 104 for HU2, 94 for HU3 and 104 for HU4. Solid fusion was not defined with invisible bridging bone connecting the adjacent vertebral bodies. ODI was 44.4% preoperatively, 8.9% at 3 months’ follow-up and 35.6% at 16-months-follow-up