Decompression vs Physical Training for the Treatment of Lumbar Spinal Stenosis
Condition: Spinal Stenosis; Spinal Stenosis Lumbar; Degeneration Lumbar Spine; Degeneration Spine; Neurogenic Claudication Co-Occurrent and Due to Spinal Stenosis of Lumbar Region; Pseudoclaudication Syndrome
MeSH terms: Spinal Stenosis; Intermittent Claudication; Constriction, Pathologic
Study type: Interventional

Summary: 
      Lumbar spinal stenosis (LSS) is characterized by low back and leg pain, walking disturbances
      and sometimes instability, impaired balance and numbness of the lower limbs. This condition
      is caused by degenerative changes in the lumbar spine including bulging discs, osteophytes
      from the arthritic facet joints and thickened ligamentum flavum which together cause
      narrowing of the spinal canal and thus affect the lumbar nerve roots. This diagnosis is
      attracting more and more interest due to the aging population with increasing demands for
      physical activity. LSS is the most common indication for spinal surgery. The surgical
      treatment involves relieving the pressure from the nerve structures in the stenotic segments
      through a posterior approach. In several studies, surgery has been shown to have better
      results than the conservative treatment. However, methodological difficulties and a large
      proportion of cross-over in these studies indicate that there is still uncertainty about
      whether surgery is generally a better option.

      It has been speculated whether the compression of the nerve roots causes in some patients
      permanent nerve damage with muscle denervation, while in other cases a reinnervation and
      recovery of the function may occur. Results from neurography and EMG studies have been shown
      these modalities to have a possible predictive value for the natural process of LSS. If a
      neurophysiological examination could be able to predict which patients are able to benefit
      from surgery, many patients could avoid surgery and the risks involved in it.

      The aim of this study is primarily to evaluate whether surgery with decompression leads to
      superior results than the non-surgical treatment with structured physical therapy.

      The main secondary aim is to investigate by means of Neurography and EMG, whether the degree
      of neurological affection caused by nerve compression affects the outcome of surgery for LSS.
    

Detailed description: 
      Background

      Lumbar spinal stenosis (LSS) is characterized by low back and leg pain, walking disturbances
      and sometimes instability, impaired balance and numbness of the lower limbs. This condition
      is caused by degenerative changes in the lumbar spine including bulging discs, osteophytes
      from the arthritic facet joints and thickened ligamentum flavum which together cause
      narrowing of the spinal canal and thus affect the lumbar nerve roots. LSS affects mainly
      older populations and is unusual under 50 years old. This diagnosis is attracting more and
      more interest due to the aging population with increasing demands for physical activity. LSS
      is the most common indication for spinal surgery. The surgical treatment involves relieving
      the pressure from the nerve structures in the stenotic segments through a posterior approach.
      The hypertrophic ligaments and parts of the facet joints are removed (i.e., decompression).
      Adding fusion to the decompression for stabilization of the decompressed segment has not been
      shown to provide superior results than decompression alone. In several studies, surgery has
      been shown to have better results than the conservative treatment. However, methodological
      difficulties and a large proportion of cross-over in these studies indicate that there is
      still uncertainty about whether surgery is generally a better option.

      After decompression, only 60-70% of patients reported to be satisfied with the result and a
      minor proportion of them experienced even no improvement at all [Strömqvist]. Conservative
      treatment has shown in some studies to have good results for some patient groups and other
      studies have shown that the benefit of the surgical treatment decreases over time and that
      physical exercise may reduce the need for surgery. Moreover, surgery itself has a positive
      placebo effect that can improve symptoms in some diseases.

      It has been speculated whether the compression of the nerve roots causes in some patients
      permanent nerve damage with muscle denervation, while in other cases a reinnervation and
      recovery of the function may occur. Results from neurography and EMG studies have been shown
      these modalities to have a possible predictive value for the natural process of LSS. If a
      neurophysiological examination could be able to predict which patients are able to benefit
      from surgery, many patients could avoid surgery and the risks involved in it.

      The degeneration of the lumbar spine is progressively impairing the spinal sagittal balance.
      The need to make extensive correction and fusion in addition to the decompression in order to
      restore the sagittal balance is debated among spinal surgeons. The experience gained from
      previous RCTs is that the patients' back pain is reduced by decompression only. Many patients
      also report that their posture improved after decompression alone.

      Previous trials in the connective tissue and blood samples have shown that proinflammatory
      factors and nociceptors (molecules that induce pain) are upregulated in patients with
      patellar tendinosis which is an inflammatory condition. Changes in the connective tissue that
      cause LSS are mainly inflammatory (arthritic facet joints and ligamentum flavum) and a
      possible theory around LSS pathophysiology may be that the nerves are biologically affected
      by proinflammatory factors and nociceptors. Identification of some of these factors could
      lead to better explanation of the pathomechanism behind the nerve compression in LSS and to
      the development of future pharmacological treatments to be used in conjunction with surgery.

      Aims

      The aim of this study is primarily to evaluate whether surgery with decompression leads to
      superior results than the non-surgical treatment with structured physical therapy. For this
      evaluation, the Oswestry Disability Index (ODI) will be used.

      The main secondary aim is to investigate by means of Neurography and EMG, whether the degree
      of neurological affection caused by nerve compression affects the outcome of surgery for LSS.

      Aims The aim of this study is primarily to evaluate whether surgery with decompression leads
      to superior results than the non-surgical treatment with structured physical therapy. For his
      evaluation, the Oswestry Disability Index (ODI) will be used.

      The main secondary aim is to investigate by means of Neurography and EMG, whether the degree
      of neurological affection caused by nerve compression affects the outcome of surgery for LSS.

      The questions at issue are:

        1. Does decompression provide a better clinical outcome than the non-surgical treatment?

        2. Is there any correlation between the clinical grade of symptoms and the degree of
           neurological affection measured by ENG/EMG?

        3. Is there any connection between the neurological affection and the proinflammatory
           markers/nociceptors in the blood as well as in histological findings from ligamentum
           flavum? Are these correlated with the clinical grade of symptoms?

        4. Does decompression provide superior neurological recovery, measured by ENG/EMG, in
           comparison to the non-surgical treatment ?

        5. Can decompression improve the spinal sagittal balance?

      Follow-up 6 months, 1, 2 and 5 years

      The results at 2 years will be the most important goal of the study, on which the main
      clinical results will be built. The neurophysiological results can be analyzed and presented
      after the 6-month follow up.

      Flow-chart

      Recruitment The patient is recruited during an outpatient visit to a surgeon. Oral and
      written information about the study is given.

      ICF The patient gives oral and written consent. The consent is documented in the patient
      journal and the written consent is filed in the study document binder.

      Baseline data - PROMs via Swespine Study

        -  6MWT

        -  Scoliosis standing digital X-rays (AP and lateral views)

        -  ENG/EMG

        -  Blood samples for analysis of inflammatory markers (OLINK)

      Randomizing Simple block randomization to the two treatment arms.

      Treatment arms A. Decompression. Central decompression of the stenotic segments with
      undercutting of the lateral recesses, free mobilization, and routine follow-up
      postoperatively by physiotherapist.

      B. Non-surgical treatment. Exercise on exercise bike according to the "Östersund model"
      [Nord] 30 min, 3 times/week for 4 months.

      Follow-up 6 months - PROMs via Swespine Study

        -  6MWT

        -  Scoliosis standing digital X-rays (AP and lateral views)

        -  ENG/EMG

        -  Blood samples for analysis of inflammatory markers (OLINK)

      Cross-over Feasibility for cross-over from group B till A after 6-month follow-up.

      Follow-up 1,2 years - PROMs via Swespine Study

      - 6MWT

      Follow -up 5 years - PROMs via Swespine Study

      In the treatment group A, in conjunction with the surgical procedure, ligamentum flavum will
      be collected (which is usually removed during the decompression surgery) and will be examined
      with histological methods regarding proinflammatory markers and nociceptors . An 1x1 cm
      tissue piece will be dissected and saved. The ligament samples will be examined by
      immunohistochemistry and with proteomics analysis. Proteomics analysis will be performed in
      collaboration with Olink Uppsala (www.olink.com) where 92 inflammation-related factors will
      be investigated. Sample management will be in accordance with the Ethics Examination Act of
      Human Research (2003: 460) and according to the rules of Uppsala Biobank.
    

Intervention name(s): Decompression
Intervention type(s): Procedure
Intervention description(s): Central decompression of the stenotic segment(s) with undercutting of the lateral recesses.
Other intervention name(s): Laminectomy
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: prospective clinical randomised clinical trial
Masking: Double (Participant, Care Provider)
Primary purpose: Treatment
Keywords: lumbar spine stenosis; decompression; laminectomy; physiotherapy; physical therapy; electroneurography; ENG; electromyography; EMG; Neurogenic Claudication; Pseudoclaudication