Lateral access to the lumbar spine has a problem that is not bony: to reach the disc you go through the psoas, and around it sit the aorta, the inferior vena cava and the ureter. That is why the learning curve of this route is about the path, not about the fusion.
Lumbar Posterior-Lateral reproduces the whole path in layers: lateral skin, subcutaneous fat, external oblique, internal oblique, transversus abdominis, transversalis fascia, retroperitoneal fat, peritoneum, and only then the psoas and the L2 to L5 vertebrae.
It takes both routes under discussion today: transpsoas and ATP, anterior to the psoas. And it takes both positions: lateral alone, or lateral then prone, to do the interbody fusion and then the pedicle fixation on the same piece.
Each at-risk structure is a separate module. When the ureter is injured in training, you replace the ureter module.
