There are three basic decisions to be made regarding spinal fusions. The first is the surgical approach. Will it be from the front of the body (anterior), back of the body (posterior), side (lateral), on a diagonal angle (foraminal), or a combination?
The second is whether the fusion will be in a straight plane or unidirectional (e.g., just anterior or just posterior). Or if the fusion will be an interbody fusion — multiple directions (circumferential) around the spinal segment.
The third is how the procedure will be done. Will it be with an open incision, mini-open, laparoscopic, or minimally invasive? Each of these decisions will influence the others, so it is up to the surgeon to decide and plan what works best for you while operating to his or her strengths (what he or she has experience with and expertise in).
The posterior lumbar interbody fusion you are going to have can be done as an open procedure or as a minimally invasive procedure. Going in from the back eliminates the risk to the abdominal organs and major blood vessels (e.g., aorta or iliac vessels). At the same time, it allows for a circumferential fusion with just the one incision. The downside of this approach is that it requires retraction (pulling away) of the dura and nerve roots. Any pulling or tugging on the nerve tissue can result in nerve damage.
The anterior lumbar interbody fusion (ALIF) avoids damage to the dura and exiting nerve roots but puts the abdominal organs, blood vessels, and nerve plexus at increased risk of injury. An ALIF will require a second approach in order to provide a circumferential fusion or when posterior stabilization is needed.
A transforaminal lumbar interbody fusion (TLIF) is minimally invasive and spares risk to the posterior structures (muscles, spinal column). But the surgeon must remove the spinal (facet) joint and that could leave the spinal segment unstable. The nerve roots have to be retracted (pulled out of the way) so there is a risk of nerve injury.
Some of the newer techniques such as XLIF and AxiaLIF are less well understood. XLIF is actually a trade name that refers to a direct lateral lumbar interbody fusion. The axial lumbar interbody fusion (AxiaLIF) is used to fuse the last lumbar vertebra (L5) to the sacrum (S1). Both of these surgical methods of spinal fusion have a short operative time and are minimally invasive.
There are many factors and variables to consider when choosing the best surgical option for each individual patient. Even weighing all the pros and cons, there may be reasons why one method would not be as good as another for you. Other things to consider include operative time, minimizing blood loss, number of spinal segments being fused, reason for the surgery, and so on.