A 40-year-old female presents with right leg pain localized to the buttock, posterior thigh, and lateral calf. In addition, she describes numbness and tingling on the dorsum of the right foot. Physical exam shows weakness to EHL. Three months of nonoperative treatment including anti-inflammatory medication, physical therapy, and selective nerve root corticosteroid injections failed to provide lasting relief and pain is still severe in nature. Her MRI is shown in Figures A and B. What would be the most appropriate management at this juncture?