Table 1. Surgical techniques and instrumentation definitions for posterior lumbar surgery and instrumentation according to the study protocol.

Term	Description
Open lumbar procedure	Surgical technique using a midline approach and requiring a partial or complete detachment of the lumbar fascia and paraspinal muscles to address the spinal pathology and placement of instrumentation
Minimally invasive procedure	Muscle-sparing surgical technique using an intermuscle- or transmuscle-splitting approach, minimizing detachment of the lumbar fascia and paraspinal muscles to address the spinal pathology and placement of instrumentation
Mini-open technique	Instrumentation placement using direct vision of target structures via an intermuscle-splitting approach
Percutaneous technique	Instrumentation placement using radiographic or navigation guidance via stab incisions without direct vision of target structures