Review Question - QID 214126

A 60-year-old female patient that is a 1 pack-per-day smoker with well-controlled diabetes presents for follow-up of lower back, buttock, L5 radicular pain, and decreased walking tolerance due to neurogenic claudication. Her current radiographs are in figure A. She has undergone 8 months of physical therapy, three lumbar epidural steroid injections, and scheduled dosing of acetaminophen and ibuprofen. Despite these efforts, she reports significant impairment in her daily function and 8/10 axial back pain at rest. The physical exam is unremarkable for neurologic deficits. She denies any bowel or bladder symptoms or saddle numbness. What is the next best step in management?