Findings from a pilot randomized trial of spinal decompression alone or spinal decompression plus instrumented fusion

Nicolas J A Beresford-Cleary; Alan Silman; Chrishan Thakar; Adrian Gardner; Ian Harding; Cushla Cooper; Jonathan Cook; Dominique A Rothenfluh

doi:10.1302/2633-1462.48.BJO-2023-0049

Findings from a pilot randomized trial of spinal decompression alone or spinal decompression plus instrumented fusion

Bone Jt Open. 2023 Aug 8;4(8):573-579. doi: 10.1302/2633-1462.48.BJO-2023-0049.

Authors

Nicolas J A Beresford-Cleary¹, Alan Silman², Chrishan Thakar¹, Adrian Gardner³, Ian Harding⁴, Cushla Cooper², Jonathan Cook^{2

5}, Dominique A Rothenfluh^{2

6}

Affiliations

¹ Oxford University Hospitals, Oxford, UK.
² Nuffield Department of Orthopaedic, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.
³ Royal Orthopaedic Hospital, Birmingham, UK.
⁴ North Bristol NHS Trust, Bristol, UK.
⁵ Oxford Clinical Trials Research Unit, Centre for Statistics in Medicine, University of Oxford, Oxford, UK.
⁶ CHUV University Hospital Lausanne and the University of Lausanne (UNIL), Lausanne, Switzerland.

Abstract

Aims: Symptomatic spinal stenosis is a very common problem, and decompression surgery has been shown to be superior to nonoperative treatment in selected patient groups. However, performing an instrumented fusion in addition to decompression may avoid revision and improve outcomes. The aim of the SpInOuT feasibility study was to establish whether a definitive randomized controlled trial (RCT) that accounted for the spectrum of pathology contributing to spinal stenosis, including pelvic incidence-lumbar lordosis (PI-LL) mismatch and mobile spondylolisthesis, could be conducted.

Methods: As part of the SpInOuT-F study, a pilot randomized trial was carried out across five NHS hospitals. Patients were randomized to either spinal decompression alone or spinal decompression plus instrumented fusion. Patient-reported outcome measures were collected at baseline and three months. The intended sample size was 60 patients.

Results: Of the 90 patients screened, 77 passed the initial screening criteria. A total of 27 patients had a PI-LL mismatch and 23 had a dynamic spondylolisthesis. Following secondary inclusion and exclusion criteria, 31 patients were eligible for the study. Six patients were randomized and one underwent surgery during the study period. Given the low number of patients recruited and randomized, it was not possible to assess completion rates, quality of life, imaging, or health economic outcomes as intended.

Conclusion: This study provides a unique insight into the prevalence of dynamic spondylolisthesis and PI-LL mismatch in patients with symptomatic spinal stenosis, and demonstrates that there is a need for a definitive RCT which stratifies for these groups in order to inform surgical decision-making. Nonetheless a definitive study would need further refinement in design and implementation in order to be feasible.