Laminectomy with Fusion for Spondylolisthesis with Foraminal Narrowing

Medical Necessity Assessment

• The patient has clear radiographic evidence of grade 2 anterolisthesis of L5 on S1, which meets criteria for fusion as this represents significant spondylolisthesis, according to the Journal of Neurosurgery guidelines 1
• MRI confirms bilateral pars defects, anterolisthesis of L5 on S1, mixed type 1 and 2 Modic endplate changes, facet arthropathy, and mild-to-moderate bilateral foraminal narrowing at L5-S1 2
• The patient has failed conservative management including physical therapy, injections, chiropractic care, and anti-inflammatory medications over an appropriate time period 2

Evidence Supporting Fusion with Laminectomy

• Guidelines strongly support fusion following decompression in patients with stenosis and spondylolisthesis, particularly in cases of grade II or higher spondylolisthesis, as recommended by the Journal of Neurosurgery 1
• The presence of pars defects in this patient further supports the need for fusion, as this represents a clear structural instability 1, 3

Instrumentation and Graft Considerations

• Pedicle screw fixation is medically necessary as an adjunct to fusion in this case, as it improves fusion success rates in patients with spondylolisthesis, according to the Journal of Neurosurgery guidelines 1
• Allograft bone is medically necessary as a bone void filler to promote fusion 3