Purpose:
To determine whether patients undergoing Anterior Lumbar Interbody Fusion (ALIF), Lateral Lumbar Interbody Fusion (LLIF), or Anterior to Psoas (ATP) procedures with minimally invasive percutaneous techniques experience muscle degeneration across the entire paraspinal muscle column or just individual muscles like the multifidus and erector spinae.
Methods:
This will be a retrospective single cohort study which compares pre- and post-operative paraspinal muscle degeneration for minimally invasive surgery (MIS). The cohort will contain 50-100 patients undergoing minimally invasive ALIF, LLIF, or ATP fusions with percutaneous techniques. Patients excluded are those who have had previous spine surgery or trauma, infection, ankylosing spondylitis, and other congenital spinal deformities.
Cross-Sectional-Area (CSA) and Muscle-Fat-Infiltration (MFI) will be taken as measurements at the surgical, inferior, and superior disc levels using the ImageJ software on T2 weighted MRI. Regions of interest include the entire paraspinal region, as well as the multifidus and erector spinae muscles individually. Images will be converted to 8-bit grayscale and threshold for fat will be set to 70px. CSA will be measured using the ImageJ polygon area function and fatty infiltration will be measured using the %area function. Pre-operative pain scores, CSA, and MFI will be compared to the same post-operative scores and measurements.
Key words: Lumbar Fusion, Percutaneous, Open, Paraspinal Muscle Degeneration, MRI