Fig. 5

The picture demonstrates the anterior approach with partial slip reduction and the posterior approach with near complete slip reduction. A L5-S1 high-grade spondylolithesis (B) ALIF lordosis cage provides sufficient anterior lengthening and posterior shortening (black arrow), achieving partial reduction, increasing LSA, and reducing L5 nerve root traction injury. C The posterior approach can almost completely reduce slips, but insufficient LSA and lordosis may cause L5 nerve root traction injury. Posterior instrumentation has been omitted from the above pictures