LimiFlex Clinical Trial for the Treatment of Degenerative Spondylolisthesis With Spinal Stenosis

A Concurrently Controlled Study of the LimiFlex™ Paraspinous Tension Band in the Treatment of Lumbar Degenerative Spondylolisthesis With Spinal Stenosis

The LimiFlex™ Clinical Trial is a prospective, concurrently controlled, multi-center study to evaluate the safety and effectiveness of decompression and stabilization with the Empirical Spine LimiFlex™ Paraspinous Tension Band compared to decompression and transforaminal lumbar interbody fusion (TLIF) with concomitant posterolateral fusion (PLF) for the treatment of lumbar degenerative spondylolisthesis (Grade I per Meyerding classification) with spinal stenosis. Clinical trial sites will enroll solely LimiFlex subjects or solely TLIF/PLF subjects.

Study Overview

• Status: Active, not recruiting
• Conditions: Lumbar Spinal Stenosis; Degenerative Spondylolisthesis
• Intervention / Treatment: Device: LimiFlex; Procedure: Decompression; Device: Fusion Instrumentation; Procedure: Fusion

Detailed Description

The LimiFlex™ Paraspinous Tension Band is a new stabilization option for patients being treated with surgical decompression for degenerative spondylolisthesis. The LimiFlex does not require pedicle screws to anchor to the spine; instead, two dynamic rods are attached to pedicle-sparing straps which encircle adjacent spinous processes.

• Study Type: Interventional
• Enrollment (Actual): 315
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Tempe, Arizona, United States, 85281
      • Sonoran Spine Research and Education Foundation
  • California
    • Oakland, California, United States, 94611
      • Kaiser Permanente Division of Research
    • Redwood City, California, United States, 94063
      • Stanford University Medical Center
    • Sacramento, California, United States, 95816
      • UC Davis Spine Center
    • Sacramento, California, United States, 95825
      • Kaiser Permanente Roseville Clinical Trials Program
    • San Francisco, California, United States, 94143
      • UCSF Dept of Orthopaedic Surgery
    • San Jose, California, United States, 95119
      • Kaiser Permanente (San Jose Medical Center)
    • Santa Monica, California, United States, 90403
      • The Spine Institute, Center for Spinal Restoration and Foundation for Spinal Restoration
  • Colorado
    • Boulder, Colorado, United States, 80303
      • Boulder Neurological & Spine Associates
  • Florida
    • Miami, Florida, United States, 33136
      • University of Miami, Dept of Neurological Surgery
    • Tampa, Florida, United States, 33607
      • BioSpine
  • Georgia
    • Atlanta, Georgia, United States, 30329
      • Emory University
  • Illinois
    • Chicago, Illinois, United States, 60612
      • Rush University
  • Indiana
    • Carmel, Indiana, United States, 46032
      • Indiana Spine Group
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • Norton Leatherman Spine Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Beth Israel Deaconess Medical Center
    • Worcester, Massachusetts, United States, 01605
      • University of Massachusetts, Dept of Orthopedics and Physical Rehabilitation
  • Michigan
    • Royal Oak, Michigan, United States, 48073
      • Beaumont Hospital
    • Royal Oak, Michigan, United States, 48073
      • Michigan Head and Spine Institute
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • New York
    • Binghamton, New York, United States, 13760
      • UHS Neurosurgery (Binghamton)
    • New York, New York, United States, 10022
      • Hospital For Special Surgery
    • Syracuse, New York, United States, 13057
      • SUNY Upstate Medical University
  • Ohio
    • Columbus, Ohio, United States, 43210
      • The Ohio State University
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19106
      • University of Pennsylvania Hospital
  • Texas
    • Plano, Texas, United States, 75093
      • Texas Back Institue, Clincal Research, LLC-Plano
  • Virginia
    • Charlottesville, Virginia, United States, 22908
      • University of Virginia Orthopaedic Surgery
  • Washington
    • Seattle, Washington, United States, 98122
      • Swedish Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria (patients must meet ALL of the following criteria to be eligible for participation in the study):

1. Lumbar degenerative spondylolisthesis (Grade I per Meyerding classification), at one level from L1 to S1, with radiographic confirmation using X-ray;

   a. Grade I spondylolisthesis per Meyerding classification includes up to 25% anterior translation of a vertebra relative to the superior endplate of the subjacent vertebra at the index level. A patient is considered to have spondylolisthesis with a minimum 10% anterolisthesis at the affected level in a lateral x-ray image.

2. Lumbar spinal stenosis requiring decompression at up to two contiguous levels from L1 to S1, inclusive of the level diagnosed with degenerative spondylolisthesis, and confirmed radiographically using CT or MRI;

   a. At the index level, lumbar spinal stenosis is at least moderate lumbar canal stenosis, defined as more than 25% reduction of the cross-sectional area compared with the next adjacent normal level, with nerve root crowding compared with the normal level, as determined by the investigator on CT Scan or MRI.

3. Neurogenic claudication or radiculopathy symptoms including leg pain, muscle weakness, and/or sensation abnormality, with or without back pain as evidenced by patient history;
4. Persistent symptoms despite at least 3 months of conservative treatment that may include but is not limited to physical therapy, medications, and/or epidural injections;

5. A pre-operative Visual Analog Scale (VAS) leg pain score of ≥50 on a 100 mm scale;

   * Leg pain includes hip and/or buttock pain on the same side

6. A pre-operative Oswestry Disability Index (ODI) score ≥35 points on a 100-point scale;
7. Candidate for surgical decompression at a single level or two contiguous levels, with stabilization at only one level between L1-S1;
8. Posterior element anatomy is appropriate for interspinous fixation including prediction of presence of spinous processes of segment to be instrumented following decompression (investigational AND control groups) and a prediction of >50% of facet joints present following decompression (investigational group only);
9. ≥25-80 years of age and skeletally mature;
10. Patient has the necessary mental capacity to participate and is willing and able to participate in the study for the duration of the study follow-up and is able to comply with study requirements; and
11. Patient is willing to provide Informed Consent for study participation.

Exclusion Criteria:

1. A primary and predominate diagnosis of discogenic back pain;
2. A primary and predominate diagnosis of facet-mediated back pain;
3. Back or non-radicular leg pain of unknown etiology;
4. Significant peripheral vascular disease causing vascular claudication;
5. Significant peripheral neuropathy caused by conditions other than spinal stenosis;
6. History of fixed or permanent neurological deficit related to spinal cord injury;
7. History of any previous surgery* at any level in the lumbosacral spine except for a discectomy or decompression;

8. History of any previous surgery* at the level planned for treatment;

   • previous surgery includes spinal stimulator placement but does NOT include epidural injections, rhizotomy or nerve ablation.
9. Isthmic spondylolisthesis or spondylolysis (pars fracture) at any level in the lumbar spine;
10. Clinically significant compromise of vertebrae at L1 to S1 levels due to osteoporotic vertebral compression fracture or any traumatic, neoplastic, metabolic or infectious pathology or congenital abnormality;
11. Spinous process fracture(s) or other posterior element fracture(s) of the segment to be instrumented that would preclude secure fixation of the LimiFlex Device to the spinous process;
12. Spinous process insufficiency or deformity that would preclude secure fixation of the LimiFlex Device to the spinous process including spinous process length <10 mm from lamina to dorsal tip or other significant deformity due to trauma, or congenital abnormality such as spina bifida occulta at the planned instrumented level that would preclude secure fixation of the LimiFlex Device to the spinous process;
13. The estimated distance between the LimiFlex Device strap attachment points (midpoint of the cranial edge of the cranial spinous process and the midpoint of the caudal edge of the caudal spinous process) is <30mm on pre-operative lateral standing radiographs at the segment to be instrumented;
14. Degenerative lumbar scoliosis with a Cobb angle >10° at the affected motion segment;
15. Symptomatic lumbar stenosis that is not amenable to a direct decompression
16. Anklyosed motion segment at the target operative level
17. Severe osteoporosis, defined as history of fragility fracture and DXA T-score <-2.5 or QCT T-score <80mg/cubic cm. History of a fragility fracture requires that a DXA scan or QCT scan is completed;
18. Planned hip or knee replacement surgery, severe osteoarthritis or other musculoskeletal pathology of the hip or leg that could preclude reliable patient self reporting assessment scales and/or that would likely progress to surgery during study period;
19. Documented allergy to titanium or polyethylene;
20. Active local or systemic infection;
21. Receiving immunosuppressive or long-term steroid therapy;
22. Known history of bone metabolic disorder, including Paget's disease, hyperparathyroidism, renal osteodystrophy, and osteomalacia;

23. Disease or condition that would preclude accurate clinical evaluation of the safety and effectiveness of the study treatment or any significant medical conditions which would place the patient at excessive risk for surgery, such as:

    1. severe rheumatoid arthritis or other severe autoimmune disease
    2. active hepatitis (viral or serum) or HIV positive
    3. unstable cardiac disease
    4. uncontrolled diabetes
    5. renal failure
    6. severe muscular, neural or vascular diseases that endanger the spinal column
    7. cauda equina syndrome
    8. severe neurologic disorders including paralysis
24. Morbid obesity defined as BMI >40;
25. Active malignancy or history of metastatic malignancy within the last five years;
26. Women who are pregnant or are interested in becoming pregnant within the study period;
27. Currently seeking or receiving worker's compensation for back pain or spinal condition;
28. Currently involved in spinal litigation that potentially is associated with secondary financial gain;
29. Current involvement in a study of another investigational product for similar purpose;
30. Demonstrates three or more Waddell's Signs of Inorganic Behavior;
31. Active treatment of a major psychiatric condition, such as major depression, anxiety disorder, bipolar disorder, schizophrenia, personality disorder, that could prevent accurate completion of self reporting assessment scales;
32. Current history (within 12 months) of substance abuse, including alcohol abuse; or
33. A prisoner.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LimiFlex; Posterior dynamic stabilization with the LimiFlex Paraspinous Tension Band	Device: LimiFlex; LimiFlex implantation at a single level after surgical decompression.; Other Names: LimiFlex Paraspinous Tension Band; Procedure: Decompression; Surgical decompression at one or two contiguous levels from L1 to S1.
Active Comparator: Fusion; Transforaminal lumbar interbody fusion with concomitant posterolateral fusion with pedicle screw instrumentation	Procedure: Decompression; Surgical decompression at one or two contiguous levels from L1 to S1.; Device: Fusion Instrumentation; Titanium alloy top-loading, polyaxial pedicle screws and cylindrical, titanium alloy rod instrumentation using autograft and/or allograft bone (i.e., cancellous and/or corticocancellous bone only), and/or a synthetic bone graft extender that is on-label for these indications (i.e., decorticated posterolateral gutter only). The TLIF requires a single PEEK or Titanium TLIF cage cleared by FDA for this indication filled with autograft and/or allograft bone (i.e., cancellous and/or corticocancellous bone only).; Procedure: Fusion; Transforaminal lumbar interbody fusion (TLIF) with concomitant posterolateral fusion (PLF) at a single level after surgical decompression.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite Clinical Success	Individual success for patients in the investigational LimiFlex or control fusion arm is assessed with Composite Clinical Success (CCS) criteria. To be considered a success, a subject must demonstrate all of the following: 15 point improvement in Oswestry Disability Index (100 point scale); Absence of a new or worsening, persistent neurological deficit; Absence of additional surgical intervention; Absence of device integrity failures	24 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oswestry Disability Index (ODI)	Oswestry Disability Index (ODI)	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Neurological Status	Neurological Status	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Additional surgical interventions	Additional surgical interventions	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Absence of device integrity failures defined as device breakage, device separation or disassembly, or device dislocation	Absence of device integrity failures defined as device breakage, device separation or disassembly, or device dislocation	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Estimated blood loss	estimated blood loss and units of blood transfused	Procedure
Length of procedure	Length of procedure (skin to skin)	Procedure
Hospital stay	Hospital stay	Immediately upon discharge
Return to normal activities of daily living	Length of time for subject to return to his/her normal activities of daily living.	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Work status	Work status and days to return to work (as appropriate)	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Pain medication including narcotics usage	Medication use for pain, including narcotic, usage	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Visual analog scale (VAS) leg pain	Leg pain as measured on a Visual Analog Scale (VAS)	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Visual analog scale (VAS) back pain	Back pain as measured on a Visual Analog Scale (VAS)	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Zurich claudication questionnaire (ZCQ)	Zurich claudication questionnaire	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
SF-12 Quality of Life survey	SF-12 Health Survey	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Patient satisfaction	Patient satisfaction questionnaire	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo
Radiographic fusion status	Radiographic fusion status	Both groups: 6 wks, 3 mo, 6 mo, 12 mo, 24 mo, 36 mo, 48 mo, 60 mo

Collaborators and Investigators

• Sponsor: Empirical Spine, Inc.
• Collaborators: MCRA; Medical Metrics Diagnostics, Inc; Biomedical Statistical Consulting
• Investigators: Principal Investigator: Rick Sasso, MD, Indiana Spine Group; Principal Investigator: William C Welch, MD, Pennsylvania Hospital Neurosurgery

Study record dates

Study Major Dates

• Study Start (Actual): July 17, 2017
• Primary Completion (Actual): June 9, 2022
• Study Completion (Estimated): July 1, 2025

Study Registration Dates

• First Submitted: March 31, 2017
• First Submitted That Met QC Criteria: April 11, 2017
• First Posted (Actual): April 14, 2017

Study Record Updates

• Last Update Posted (Actual): February 20, 2024
• Last Update Submitted That Met QC Criteria: February 15, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Pathological Conditions, Anatomical; Spinal Diseases; Bone Diseases; Spondylolysis; Spondylosis; Constriction, Pathologic; Spinal Stenosis; Spondylolisthesis
• Other Study ID Numbers: LSS17001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes