Instability in the Lumbar Spine of Patients With Age Related Changes and Narrowing of the Spinal Canal (Spinal Stenosis)

Study Overview
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Brief Summary
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Age related changes in the lumbar spine can lead to narrowing of the spinal canal (spinal stenosis) causing leg and back pain. Spinal stenosis can be associated with a misalignment of the spine caused by forward slippage of a vertebrae over another. This instability is diagnosed using diagnostic imaging. With signs of instability the spine surgeon might choose a fusion of the vertebrae. This is a more complex procedure in relation to the simple decompression preformed without instability for spinal stenosis. The purpose of this study is to identify characteristics of instability of the lumbar spine on diagnostic imaging, and investigate associations with surgical data and patient reported outcomes from the National Spine databases from Denmark and Sweden. This will support spine surgeons in providing evidence-based surgical treatment for spinal stenosis with or without signs of instability

Detailed Description
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A multicenter retrospective cohort study of prospectively collected data from national spine surgery databases in Denmark and Sweden. This project is a collaboration between sector for spine surgery and research Middelfart Hospital and spine surgeons at Orebro Hospital and Lund Hospital in Sweden. Data subtracted from Danish national spine surgery database, DaneSpine, from Middelfart Hospital, and Swedish Spinal Register, SweSpine, from hospitals in Malmö, Lund, Trelleborg and Karlskroga. Both databases are clinical quality databases with a high response-rate. DaneSpine is administered by Danish Society of Spine Surgeons and is managed by secretary of DaneSpine. SweSpine is administered by Swedish Society of Spinal Surgeons and managed Patients are invited to register when scheduled for surgery. Patients signs informed consent and receives follow-up questionaires 3 and 6 months, one, two, 5 and 10 years post-surgery. Questionaires are validated PROM (patient reported outcome measures) and PREM (patient reported experience measures). The surgeon is responsible for registering surgical data, including complications and reoperations. Data relevant for present study will be applied for at the respective societies and managed and stored in compliance with General Data Protection Regulation. The EasyWiz software (Medical Insight, Chicago, IL, USA) is used for analysis of all MRIs and radiographs. All imaging will be analyzed by 2 independent examiners. The interobserver reliability will be calculated. Missing data such as variables reported as missing or non-reported will not be included in statistical analysis. Statistics: significance of difference in mean values between groups for continuous normally distributed data unpaired t-test. Categorical variables normally distributed: Chi-squared/Fishers exact test. Multivariable regression analysis. Kappa statistics for interobserver reliability presented in the article.

Official Title
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Degenerative Segmental Instability in Lumbar Spinal Stenosis Patients - Study on Instability, Clinical Outcomes, Reoperation Rate With a 2 Year Follow up

Conditions
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Degenerative Lumbar Spinal Stenosis, Degenerative Spondylolisthesis

Intervention / Treatment
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* Procedure: decompression
* Procedure: fusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - MRI verified spinal stenosis patients with or with out degenerative spondylolisthesis (> 3mm anterior translation in lumbar MRI), who underwent surgery at L4/L5 level with either decompression alone or decompression with fusion between 2010 and 2017. Included ICD-10 diagnostic groups DM480 and DM431. Must have standing lateral radiographs preoperatively. Completed 2 year follow up. Exclusion Criteria: previous surgery at the same level, malignancy or undergoing treatment for malignancy scoliosis Cobb angel >20 degrees

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 110 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| decompression<br>patients treated with decompression for lumbar spinal stenosis | Procedure: decompression<br>* surgical technique for neural decompression varied based on surgeon's preference, but always with preservation for spinous processes. Either open with or without microscope or using tubular retractors.<br>|
| fusion<br>patients treated with decompression with fusion for lumbar spinal stenosis | Procedure: fusion<br>* fusion techniques consisted besides decompression of additional implantation of pedicle screws with rods, with or without intervertebral fusion and cage(s). Non-instrumented technique with allograft bone. Fusion technique on surgeon's discretion.<br>* Other names: arthrodese;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| facet joint gap | MRI proxies 1 | pre-surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| facet angel | MRI proxies 2 | pre-surgery | 
| disc height | MRI proxies 3 | pre-surgery | 
| anterior translation | MRI proxies 4 | pre-surgery | 
| intradiscal vacuum | MRI proxies 5 | pre-surgery | 
| radiographic slip | anterior translation on lateral radiograph | pre-surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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instability, anterior translation, slip, segmental motion, radiologic assesment, lumbar MRI, MRI characteristics