The clinical and cost-effectiveness of lumbar fusion surgery for patients with persistent, severe low back pain: FusiOn veRsus bEst coNServatIve Care (the FORENSIC-UK trial)

Research Question For people with persistent severe low back pain (LBP) and lumbar degenerative disease, is lumbar fusion surgery more clinically, and cost effective than continued best conservative care, as measured by the Oswestry Disability Index at 24 months FU. Background Lumbar fusion is an operation in which vertebrae are fixed together to reduce or alleviate LBP. Uncertainty exists over its effectiveness, especially compared to conservative care (1-4) leading to NICE (5) stating that it should only be used in a randomised trial (RCT). As a result, the frequency of surgery has reduced substantially. However, there is a concern that spinal fusion may still be useful and provide a beneficial last option in patients who have failed all non-surgical treatments. Aims and Objectives To test for superiority of lumbar fusion versus continued best conservative (non-surgical) care on disability (physical function) and cost effectiveness in patients with persistent LBP. Methods Design: A multicentre, 2 arm superiority RCT with internal pilot, integrated QRI & health economic analysis. Patients will be randomised (1:1) to either Lumbar Fusion Surgery (LFS) or continued Best Conservative Care (BCC). Patients: 270 patients (135 per arm) from 20 NHS musculoskeletal/spinal clinics. Adults aged <60 with persistent severe LBP (duration=6 months) with MRI evidence of lumbar degeneration who have already undergone previous conservative treatment. A Quintet Recruitment Intervention (QRI) is included. Interventions: For Lumbar Fusion Surgery, all standard fusion methods are allowed. The content of Best Conservative Care includes non-surgical intervention elements identified from NICE (5) the National Low Back and Radicular Pain Pathway (NLBPP), and an expert Clinical Advice Group. Outcomes: The primary outcome is the validated Oswestry Disability Index for back pain at 24 months follow-up. Secondary measures include LBP intensity, global rating of change (NRS), quality of life (EQ-5D-5L), depression (PHQ9), anxiety (GAD7), fear avoidance beliefs (TSK), self-efficacy beliefs (PSEQ), work outcomes (days-off-work), treatment and outcome satisfaction, adverse events, revision/further surgery, and concurrent treatments. Analysis: The sample size is based on a target difference of 8 points on the ODI (effect size 0.44), 5% significance level, 90% power and allowing for up to 20% loss to follow-up. An Intention-to-treat (ITT) is planned for the primary outcome (ODI) with differences between groups estimated using a mixed effects regression model. The health economic evaluation will estimate the cost per additional quality-adjusted life year (QALY) and incremental net benefit of fusion surgery over 24 months. Public Patient Involvement: PPI input has been extensive and will shape every aspect of the trial including conduct, recruitment, and qualitative data interpretation. Timelines Total 62 months: 8 mths set up, 10 mth internal pilot,14 mths main recruitment, 24 mths FU up from last recruitment; 4 mths analysis; 2 mths writing. Impact & dissemination The results will have high impact and substantially change or confirm practice. Should spinal surgery show little benefit over conservative care then it should remain a non-commissioned treatment option. Should spinal fusion surgery be beneficial then it should be offered under NICE guidelines for appropriate patients. Dissemination will be through journals, news media and conference.