Decompression vs. Fusion for Stable Degenerative Spondylolisthesis

Decompression Alone vs. Decompression and Instrumented Fusion for the Management of Lumbar Spinal Stenosis Associated With Stable Degenerative Spondylolisthesis: A Pragmatic Randomized Clinical Pilot Trial

The purpose of this study is to assess the feasibility of a full-scale multicenter randomized, controlled trial comparing the effectiveness of two surgical treatments for a condition associated with lumbar spinal stenosis called degenerative lumbar spondylolisthesis. Both treatments are currently used, but individual surgeons use different selection criteria for each treatment and use the procedures at different rates. The two procedures are decompression with fusion (the most common surgical procedure for spondylolisthesis) and midline-sparing decompression alone (which is also a standard treatment, but is not as widely used for treating spondylolisthesis). The investigators plan to collect the evidence on the following:

1. The feasibility of the trial protocol, and
2. Preliminary data on the effectiveness of each treatment.

Study Overview

• Status: Completed
• Conditions: Spinal Stenosis; Spondylolisthesis
• Intervention / Treatment: Procedure: Spinal fusion; Procedure: Spinal decompression

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2N 2N9
      • Foothills Medical Centre
    • Edmonton, Alberta, Canada, T6G 2B7
      • Mackenzie Health Sciences Centre
  • British Columbia
    • Vancouver, British Columbia, Canada, V5Z 1M9
      • Vancouver General Hospital
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3H 2Y9
      • Queen Elizabeth II Health Sciences Centre
  • Ontario
    • London, Ontario, Canada, N6A 5W9
      • London Health Sciences Centre - Victoria Hospital
    • Toronto, Ontario, Canada, M4N 3M5
      • Sunnybrook Health Sciences Centre
    • Toronto, Ontario, Canada, M5T 2S8
      • University Health Network
  • Quebec
    • Montreal, Quebec, Canada, H3G 1A4
      • Montreal General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 46 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients deemed to be surgical candidates with focal (1-2 level) lumbar spinal stenosis (LSS) and associated stable degenerative spondylolisthesis with the following characteristics:

  1. a clinical history of back, buttock and leg pain with walking or standing that is improved when lying, sitting or bending forward
  2. a clinical history of leg symptoms that are greater than or equal to back symptoms with walking or standing, and
  3. greater than 6 months of symptoms with failed conservative care
• aged 50 or over
• sufficient fluency in English or French to provide informed consent and complete questionnaires with or without the need of an interpreter

Exclusion Criteria:

• Greater than 25% listhesis or spinal instability as demonstrated by motion (>5mm of translation) on flexion extension radiographs or non-loaded (MRI/CT or supine x-rays) to loaded imaging (standing radiograph)
• Presence of kyphosis (>0 degrees at the affected level or globally), degenerative scoliosis (>10 degree using the Cobb method) with rotatory or lateral listhesis on preoperative x-rays
• Clinical history of osteoporotic fracture or chronic oral steroid use
• Previous posterior lumbar spinal surgery (excluding prior microdiscectomy)
• Patients who have evidence of neurological disorders that affect physical function (e.g. peripheral neuropathy), neuromuscular disorders (e.g. multiple sclerosis, Parkinson's etc.) or systemic illness (e.g. inflammatory arthritis) that affects physical function

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Decompression with fusion; Spinal decompression surgery with instrumented spinal fusion	Procedure: Spinal fusion; Procedure: Spinal decompression
Active Comparator: Decompression alone; Midline-sparing spinal decompression alone	Procedure: Spinal decompression

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients recruited		1 year
Number of eligible patients		1 year
Reasons for refusal to consent		1 year
Proportion of patients who adhere to randomized allocation		2 years
Number of patients refusing to consent due to blinding		1 year
Blinding status	Patient's assessment of which treatment they received	1.5 months post-surgery
Oswestry Disability Index (ODI)	10-item patient-reported questionnaire measuring disability related to low back pain. Each item has six response options ranging from 0 to 5; the responses are summed and rescaled so 0 indicates no disability and 100 indicates extreme disability.	6-18 weeks, 6 months (optional), 12 months, and 24 months post-surgery
Proportion of patients who receive randomized allocation		2 years
Number of patients refusing to consent due to randomization		1 year
Number, type and severity of adverse events		End of hospital stay (average 6.5 days post-surgery)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Short-Form 12 scores: Physical Function, Bodily Pain, Physical Component Summary	12-item patient-reported questionnaire for general health status based on the SF-36 Health Survey (version 2). Measures eight health domains, each scored so 0 is the worst and 100 is the best possible score: general health (GH), physical function (PF), bodily pain (BP), role limitations due to physical problems (RP), role limitations due to emotional problems (RE), mental health (MH), social functioning (SF), and energy/fatigue (VT). The domain scores can be aggregated into Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, also scaled so 0 is the worst and 100 is the best possible score. This study will focus primarily on the Physical Function domain, the Bodily Pain domain, and the Physical Component Summary score.	Baseline; 6-18 weeks, 6 months (optional), 12 months, and 24 months post-surgery
Euro-QoL health utility index	Patient-reported questionnaire for general health state which includes five items (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) and a visual analog scale for self-rated health state. Using an existing U.S. population-based value set, responses will be converted to the corresponding health utility index (1.0=perfect health and 0.0=death).	Baseline; 6-18 weeks, 6 months (optional), 12 months, and 24 months post-surgery
Patient Health Questionnaire-9 score	Patient-reported questionnaire that measures severity of depression symptoms. It is scored from 0 to 27, with the following interpretation: 0-4=no symptoms, 5-9=minimal symptoms; 10-14=mild/minor depression or dysthymia; 15-19=moderate major depression; 20-27=severe major depression.	Baseline
Costs incurred by patients		monthly from 1.5 to 12 months post-surgery; 24 months post-surgery
Hospital cost		End of hospital stay (average 6.5 days post-surgery)
Healthcare services used	Other Ontario Health Insurance Plan (OHIP)-billed services used	Referral to 1 year post-surgery

Collaborators and Investigators

• Sponsor: University Health Network, Toronto
• Investigators: Principal Investigator: Yoga Raja Rampersaud, MD FRCSC, University Health Network, Toronto; Principal Investigator: Anthony Perruccio, PhD, University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2015
• Primary Completion (Actual): August 1, 2023
• Study Completion (Actual): August 1, 2023

Study Registration Dates

• First Submitted: September 9, 2014
• First Submitted That Met QC Criteria: January 22, 2015
• First Posted (Estimated): January 28, 2015

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 1, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Quality of Life; Low Back Pain; Laminectomy; Neurosurgery; Orthopedics; Spine; Spinal Fusion; Intervention studies; Neurosurgical Procedures; Pilot projects; Feasibility studies; Orthopedic Procedures; Spondylodesis; Spondylosyndesis; Foraminotomy; Decompression, surgical
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Bone Diseases; Musculoskeletal Diseases; Spinal Diseases; Back Pain; Spondylolysis; Spondylosis; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Spinal Stenosis; Low Back Pain; Spondylolisthesis; Therapeutics; Surgical Procedures, Operative; Neurosurgical Procedures; Orthopedic Procedures; Decompression, Surgical; Arthrodesis; Laminectomy; Spinal Fusion
• Other Study ID Numbers: 13-6927