Impact of Chronic Preoperative Gabapentinoid Exposure on Surgical and Patient Reported Outcome Measures following Lumbar Fusion.

Study design: Retrospective cohort.

Objective: To assess the relationship between long-term gabapentinoid use and outcomes after lumbar fusion.

Summary of background data: Gabapentinoids, which include gabapentin and pregabalin, are commonly prescribed for radiculopathic pain. Basic science research has indicated that gabapentinoids may be detrimental to bone health/healing and clinical works has shown that initiating gabapentinoids at the time of spine surgery may decrease postoperative opioid requirements and increase risks of adverse outcomes. Despite these findings, no literature exists examining the impact of chronic gabapentinoid prescriptions on outcomes after lumbar fusion.

Methods: Adult patients who underwent elective one/two-level lumbar fusion (2017-2022) were identified via Structured Query Language search. Patient demographic/surgical characteristics, surgical outcomes, patient-reported outcome measures (PROMs), and preoperative gabapentinoid use were collected. Perioperative opioid data were collected utilizing the Pennsylvania Prescription Drug Monitoring Program. Appropriate statistical analyses were conducted with alpha set at 0.05.

Results: Amongst 461 included patients, 47 (10.2%) and 61 (13.2%) were chronically prescribed pregabalin and gabapentin, respectively. All groups were similar in terms of demographics, and surgical type/complexity. There were no differences in surgical outcomes, including two-year revision rate. Patients taking pregabalin consumed more total MMEs compared to gabapentin (132±344 vs. 104±351, P=0.022) and non-gabapentinoid patients (132±344 vs. 90.3±267, P=0.007). However, preoperative total MMEs were similar 60 days prior to surgery. Bivariate analysis demonstrated postoperative differences in back pain improvement at six-months (P=0.025) between groups, however pairwise comparison did not show significance. Similarly, multivariate analysis did not show gabapentinoid usage as independently predictive of back pain scores. All other PROM comparisons were similar between groups.

Conclusion: Despite compelling basic science literature suggesting gabapentinoid exposure hindering bone health and healing capacity, the current investigation did not find an increase in surgical revision or other adverse outcomes, including opioid use and PROMs, associated with chronic preoperative gabapentinoid use.