The purpose of the this study to evaluate the feasibility, safety, and efficacy of a fluoroscopically-guided dorsal ramus block placed by the operative neurosurgeon prior to lumbosacral surgery. The study will consist of a retrospective analysis of a cohort of patients who underwent lumbosacral surgery patients between June 2018 and March 2021 with or without a preoperative fluoroscopically-guided dorsal ramus (DR) block placed by the operative neurosurgeon.

Spine surgery poses unique challenges in postoperative pain management. Local anesthetic blocks, namely the erector spinae plane and thoracolumbar interfacial plane blocks, placed by anesthesia under ultrasound guidance have been shown to reduce postoperative pain after spinal surgery and decrease perioperative opioid requirements by as much as 50%. Nonetheless these procedures are not routinely performed, likely due to logistical hurdles and lack of widespread knowledge of the procedure by anesthesiologists. A preoperative dorsal ramus block performed by the operative neurosurgeon under fluoroscopy shows promise as an alternative approach to perioperative pain control. The objective of this retrospective observational study is to evaluate the feasibility, safety, and efficacy of a dorsal ramus block block performed by a neurosurgeon under x-ray guidance prior to lumbar surgery. The study will include a cohort of patients who have undergone lumbar spine surgery with or without the x-ray guided dorsal ramus block. A retrospective chart review of these patients will be performed to assess for postoperative pain control, postoperative opioid requirements, time to block completion, length of stay, and adverse events. Descriptive and comparative statistics will be performed. No new data will be gathered from the subjects beyond pre-existing data within the medical record, and no new procedures will be performed as part of the study. If the current study suggests that a dorsal ramus block performed by the operative neurosurgeon is feasible, safe, and effective, it will serve as a foundation for a randomized clinical trial of such a block among patients undergoing lumbar surgery.

Inclusion Criteria:

• Patients aged 18 years and older
• Patients undergoing lumbar spine surgery at any spinal level from L1 to sacrum (including decompression, discectomy, posterior fusion, interbody fusion, wound revision or washout, intradural tumor resection, treatment of vascular spinal lesion, tethered cord release, repair of cerebrospinal fluid (CSF) leak, hardware removal)

Exclusion Criteria:

• Patients undergoing surgery that includes thoracic levels
• Patients from whom pain scores could not be elicited in the immediate postoperative period due to mental status (e.g. prolonged intubation requirement, etc.)

The population consists of a convenience sample of patients undergoing lumbar spine surgery at a tertiary care academic medical center and an associated specialized spine hospital.