So these surgeons have not really been planning an ALIF but really planning a “360” or a variant of a front and back fusion. I have seen this pattern before. The simple “roll you over to put in screws is really a posterior approach and not “simple”.
This begs the question as to why they would plan an ALIF which is a stand alone procedure when they really plan a 360 but without any of the benefit of the posterior approach. If you are going to have a posterior incision and screw placement, why not avoid any of the anterior risks and do the entire surgery from one small incision in the back?
This idea of placing screws in the back without the benefits of a decompression or a fusion of the facets and transverse processes bewilders me. The surgeon is already there, can place screws and still do a fusion as well as a decompression and does nothing but place screws. It makes no sense.
A disc herniation cannot be decompressed from the front without some risk to the nerves and dural sac. It is much better to directly look at the nerves being decompressed and decompress then under direct visualization (see microdisc video to understand this concept) than to attempt to decompress indirectly.
Remember that a solid fusion of the disc space and posterior elements will be strong regardless of the approach. The argument that the anterior fusion is stronger is simply not true. The size of the cage is really not relevant as long as a cage of 6mm or larger is placed.
The pars fractures that caused the isthmic spondylolisthesis separates the facets from the entire vertebra. Preserving the facets will not make a difference in stability, but there are detriments to not removing them.
These facets are great bone graft sources and should be used for graft. Not using them again makes absolutely no sense. This graft can make the difference between a solid fusion and no fusion at all. In addition, there is typically a large spur that grows off the bottom of the pedicle of L5 where the fracture originates. This spur compresses the L5 root and can cause compression if the disc is distracted by a intradiscal cage.