SLIP II Registry: Spinal Laminectomy Versus Instrumented Pedicle Screw Fusion (SLIP II)
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ClinicalTrials.gov Identifier: NCT03570801 |
Recruitment Status :
Terminated
(We performed unplanned interim conditional power (CP) analyses for the primary endpoint. We pre-specified futility as CP<20%. Based on 301 patients (38% of target), CP was <20% and the independent steering committee recommended termination.)
First Posted : June 27, 2018
Last Update Posted : August 2, 2022
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The purpose of the project is to perform an RCT comparing patient satisfaction and outcome with or without the use of an expert panel. The purpose is also to create a registry to compare the effectiveness of decompression alone versus decompression with fusion for patients with degenerative grade I spondylolisthesis and symptomatic lumbar spinal stenosis. Primary analysis will focus on the patients' improvement from baseline patient-reported outcome questionnaires.
In addition, the SLIP II registry aims to (i) develop an algorithm which could identify cases in which surgical experts are likely to recommend one treatment (i.e. >80% of experts recommend one form of treatment) and (ii) develop a radiology-based machine learning algorithm that would prospectively classify patients as either 'stable' or 'unstable.'
In addition to patient reported outcomes, step counts will be collected in order to determine the correlation of step count with patient-reported outcomes (ODI and EQ-5D) and the need for re-operation.
This registry portion of the study aims to prospectively collect comparative data for these patients treated with either decompression alone or decompression with fusion.
Condition or disease | Intervention/treatment | Phase |
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Lumbar Spondylolisthesis Grade 1 Spondylolisthesis Lumbar Spinal Stenosis Degenerative Spondylolisthesis | Other: Expert Panel Review | Not Applicable |

Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 662 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Randomized Control Trial with randomization ratio 1:1 |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | SLIP II Registry: Spinal Laminectomy to Laminectomy With Instrumented Pedicle Screw Fusion for Lumbar Stenosis With Grade I Spondylolisthesis |
Actual Study Start Date : | October 17, 2017 |
Actual Primary Completion Date : | July 1, 2022 |
Actual Study Completion Date : | July 1, 2022 |
Arm | Intervention/treatment |
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Experimental: Expert Panel Review
For patients who are randomized to receive an expert panel review, de-identified lumbar MRI (sagittal and key axial images), 36-inch standing plain radiographs (if available), and flexion and extension radiographs will be uploaded into a web-based platform and reviewed. These will be submitted for an Expert Panel Review. Images will be reviewed through a Spine Expert's Network, consisting of physicians involved in this study who will each offer their opinion as to which of two surgical treatment groups (decompression alone or decompression with fusion) they would choose for the patient. The results of this review will be discussed between the patient and the patient's physician. Together, they will determine the best surgical approach. |
Other: Expert Panel Review
There is some preliminary evidence suggesting that having a group of spinal experts review x-rays prior to treatment might provide useful information to the patient and the patients' treating physician when trying to make a decision about what type of surgery to perform. |
No Intervention: No Expert Panel Review
For patients not receiving the expert panel review, they will discuss with their surgeon the best surgical option and proceed as they would in standard of care.
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- NASS Patient Satisfaction [ Time Frame: 1 year, 2 years, 3 years, 4 years, 5 years ]To determine at 1 and 2 years if an expert panel review of individual cases is associated with an 8% difference in the percentage of patients who achieve at least 1) the treatment met expectations or 2) did not improve as much as hoped but would undergo the same treatment for the same outcome.
- Oswestry Disability Index (ODI) [ Time Frame: Baseline, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]To determine at 1 and 2 years if an expert panel review of individual cases is associated with a greater percentage of patients who improve by more than 10 points. In addition, we will compare mean change in ODI score among patients randomized to expert panel review to those randomized to receive no review.
- Oswestry Disability Index (ODI) [ Time Frame: Baseline, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]To compare mean change in ODI score between patients treated with laminectomy alone versus laminectomy with instrumented lumbar fusion
- EuroQol-5 Dimensions (EQ-5D) [ Time Frame: Baseline, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]Quality of life will be assessed through EuroQol 5 Dimensions (EQ-5D) at all time points. The three-level scale denotes no problems, some problems, or extreme problems, across the five domains of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. A visual analog scale is also used to evaluate overall health state. Comparisons among groups will compare difference in the change scores.
- Cost Data -- Hospital Claims & Health Resource Utilization [ Time Frame: 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]Costs will also be compared between groups during the duration of the study.
- Complications [ Time Frame: 1 month ]Complications at time of surgery to 30 days post-operative will be collected.
- Return to Work [ Time Frame: Baseline, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]Working status will be asked at all time points to capture productivity.
- Flexion-Extension Radiographs [ Time Frame: Baseline, 1 year, 2 years ]To determine stability after surgery as well as fusion.
- 36-inch Standing Plain Radiographs [ Time Frame: Baseline, 1 year ]To assess spine alignment.
- Step Count [ Time Frame: Baseline, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, 5 years ]Step count will also be evaluated against outcomes (ODI and EQ-5D) and re-operations.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Symptomatic lumbar spinal stenosis: defined as radicular and/or back pain either induced or aggravated by activity and relieved by rest.
- Single-level grade I degenerative spondylolisthesis (3-14mm)
Exclusion Criteria:
- Serious medical illness (ASA Class IV or higher)
- Spondylolysis
- Multilevel spondylolisthesis or high grade spondylolisthesis (grade II or greater than 14mm)

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03570801

Principal Investigator: | Zoher Ghogawala, MD | Lahey Hospital & Medical Center |
Responsible Party: | Lahey Clinic |
ClinicalTrials.gov Identifier: | NCT03570801 |
Other Study ID Numbers: |
2017-047 |
First Posted: | June 27, 2018 Key Record Dates |
Last Update Posted: | August 2, 2022 |
Last Verified: | July 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | Deidentified data would be shared with other researchers after primary analysis has been published. |
Supporting Materials: |
Study Protocol Statistical Analysis Plan (SAP) |
Time Frame: | After primary analysis has been published for up to 5 years. |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Lumbar Spondylolisthesis Grade 1 Spondylolisthesis Lumbar Spinal Stenosis Degenerative Spondylolisthesis |
Spinal Stenosis Spondylolisthesis Constriction, Pathologic Pathological Conditions, Anatomical Spinal Diseases |
Bone Diseases Musculoskeletal Diseases Spondylolysis Spondylosis |