Clinical Trial Comparing Decompression With and Without Coflex™ Interlaminar Technology Treating Lumbar Spinal Stenosis

Not Applicable

Completed

Conditions: Spinal Stenosis

Interventions: Device: Implantation of coflex™ after surgical decompression
Procedure: Surgical decompression

Registration Number: NCT01316211

Lead Sponsor: Paradigm Spine

Brief Summary: A 2 year comparative evaluation of clinical outcome in the treatment of degenerative spinal stenosis with concomitant low back pain by decompression with and without additional stabilization using the coflex® Interlaminar Technology

Detailed Description: The coflex® implant for interlaminar stabilization has been in clinical use for more than 10 years and is CE-certified according to the standards and approved in the United States.

This was a randomized multicenter study to collect prospective data for potential improvement in the therapy of low back pain during the treatment of spinal stenosis. The study was conducted in Germany.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 246

Inclusion Criteria

Radiographic confirmation of clinical symptoms of at least moderate degenerative spinal stenosis, with constriction of the central spinal canal of one or two adjacent segments in the region L3 to L5 with the need for decompression.

If necessary additional decompression in the adjacent segment(s) may be performed avoiding any instability in the affected segment.

In addition the following may exist (but is not obligatory):
- hypertrophy of the facet joints and subarticular recessus stenosis in the relevant segment or
- stenosis of the foramen in the relevant segment
- and/or stable retrolisthesis up to grade I verified by flexion-/extension X-ray films.
Radiographic confirmation of no translatory instability in the main segment as well as in adjacent segments (dynamic translatory instability ≤ 3 mm).
VAS back pain score of at least 50 mm on a 100 mm scale (for acute back pain or a period of at least 3 month of back pain before the onset of leg pain).
Minimum of 3 months conservative therapy without improvement of symptoms.
Age >40 years.
Oswestry Low Back Pain Disability Questionnaire score of at least 18/45 (40%) for German sites or 20/50 (40%) for the US sites (The question about sexual life will be excluded).
Suitability of the patient for a posterior surgery procedure.
Mental and physical ability of patient to follow the protocol according to compliance to time schedule, treatment plan, fill in of CRF pages and further study procedures.
Personally signed informed consent form before the start of any study related procedures.

Exclusion Criteria

Any of the following will exclude a subject from the study:

Preceding fusion or decompression surgery of the lumbar spine or preceding nucleotomy of the segments of concern (also if nucleotomy becomes necessary during surgery).
Radiographically confirmed damage of the vertebral body in the segment of concern in the lumbar spine (e.g. osteoporotic compression fracture or because of tumors)
Isthmic and degenerative spondylolisthesis (anterolisthesis; retrolisthesis > grade I) or spondylolysis (Pars fracture).
Degenerative lumbar scoliosis (> 25°).
Adipositas (obesity). Defined as a body mass index >40.
Pregnancy, or wish to get pregnant during the course of the study.
Known allergy for titanium and titanium alloys.
Fluoride infections - both systemic and local.
History of severe peripheral neuropathy.
Significant peripheral vascular disease (claudication intermittens ≥ stage 2b).
M. Paget or osteomalacia or other metabolic bone disorders.
Cauda equina syndrome.
Communicating diseases, including HIV, active hepatitis
Patients who are lawfully kept in an institution.
Subjects who, in the opinion of the investigator, will be inappropriate for inclusion into this clinical trial or will not comply with requirements of the study.
Subjects who participated in a clinical observation or therapy with X-ray during the last 10 years.
Subjects who participate(d) in another clinical trial (within the last 4 weeks) that might influence the safety and effectiveness assessment of this trial.

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
coflex™	Implantation of coflex™ after surgical decompression	Implantation of coflex™ device in assigned patients
Surgical decompression	Surgical decompression	Surgical decompression in patients with spinal stenosis without stabilization by an additional implant.

Primary Outcome Measures

Name	Time	Method
Change in ODI From Baseline to 24 Months	Baseline, 3, 12, and 24 months	The ODI, also known as the Oswestry Low Back Pain Disability Questionnaire is a questionnaire providing information on back and leg pain and the affects on managing everyday life by dividing questions into 10 sections. For this study, the questions on sexual activity will not be asked. The total possible score for each section is 0-5. The scores are then converted percentages ranging from 0% (minimal disability) to 100% (maximum possible disability).

Secondary Outcome Measures

Name	Time	Method
Neurological Status - Mean Change in Muscle Strength From Baseline to 24 Months	Baseline, Day 0 (Surgery), 3, 12, and 24 months	Muscle strength will be assessed on right/left muscle strength at 6 groups of leg muscles. Score ranges from 0=contraction to 5=normal.
Number of Participants With Adverse Events - Operative Site	2 years	Number of Participants that experience adverse events related to the operative site from each group.
Neurological Status- Mean Change in Ilio Sacral Joint Affection Test From Baseline to 24 Months.	Baseline, Day 0 (Surgery), 3, 12, and 24 months	Ilio sacral join affection test was used to assess the neurological status of a subject. The test was taken for both the left and right sides and assessed as not present/absent (no= corresponding with a value of 1) or present (yes= corresponding to a value of 2). The average of each patient's worst side was calculated. Mean values closer to 1 indicate more patients with an absent llio sacral joint affection and a decrease in the mean change indicates more patients improving from a present to absent sacral join affection.
Change in Visual Analog Scale (VAS) Leg Pain From Baseline to 24 Months	Baseline, 3, 12, and 24 months	Improvement of the Visual Analog Scale (VAS) for leg pain (on the 100mm scale) compared to control group. 0 = no pain and 100 = worst pain imaginable.
Neurological Status - Mean Change in Sensory Deficit From Baseline to 24 Months	Baseline, 3, 12, and 24 months	Sensory deficits will be assessed at nerves roots from L3, L4, L5, and S1. Grading score ranges from 1=absent to 3=normal.
Number of Participants With Significant Migration or Expulsion of the Implant	2 years	Assess significant migration, defined as \> 5mm by x-ray images (point of reference is the tip of the U-portion implant identified on the corresponding x-ray image).
Change in Visual Analog Scale (VAS) Back Pain From Baseline to 24 Months	Baseline, 3, 12, and 24 months	Improvement of the Visual Analog Scale (VAS) for low back pain (on the 100mm scale) compared to control group. 0 = no pain and 100 = worst pain imaginable.
The Percentage of Patients With Survival Probability as Assessed by Evaluating Treatment Failure in Both Groups..	2 years	Treatment failure is defined as any secondary intervention, severe adverse event or other parameters that define the device as ineffective or not safe. The following events/outcomes were defined as treatment failures: wound revisions, patients with trauma requiring surgical intervention, disc hernia or dura repair, and/or pain management.
Change of Symptoms- Zurich Claudication Questionnaire (ZCQ) After 24 Months Compared to Baseline.	Baseline, 3, 12, and 24 months	The symptom severity scale ranges from 0 to 5 where a higher score indicates a worse outcome. Percentage of the maximum reported score for the symptom severity scale was calculated at baseline and 24 months and change in percentage score is reported in the Outcome Measure data table.
Number of Participants Receiving Epidural Injections	2 years	Epidural injections at up to 24 months
Neurological Status- Mean Change in Trendelenburg Sign Test From Baseline to 24 Months.	Baseline, Day 0 (Surgery), 3, 12, and 24 months	Trendelenburg's sign was used to assess the neurological status of a subject. The test was taken for both the left and right sides and assessed as not present/absent (no= corresponding with a value of 1) or present (yes= corresponding to a value of 2). The average of each patient's worst side was calculated. Mean values closer to 1 indicate more patients with an absent Trendelenburg's sign, and a decrease in the mean change indicates more patients improving from a present to absent Trendelenburg's sign.
Change in Functionality- Zurich Claudication Questionnaire (ZCQ) From Baseline to 24 Months	Baseline, 3, 12, and 24 months	The symptom severity scale ranges from 0 to 5 where a higher score indicates a worse outcome. Percentage of the maximum reported score for the symptom severity scale was calculated at baseline and 24 months and change in percentage score is reported in the Outcome Measure data table.
Assessment of Time to Symptoms Utilizing Walking Distance Test	2 years	During this test, a patient has to walk on a treadmill (speed 1.8 km/h \[12\]) for 15 minutes (450 m) on a 0 degree ramp incline. It will be assessed time to first symptoms, time to severe symptoms and nature of symptoms (leg weakness, leg pain, back pain, or generalized fatigue, other). A time of zero will be recorded when symptoms were present at onset. The examination will be stopped after 15 minutes or at the onset of severe symptoms. Definition of severe symptoms is: The level of discomfort that would make patients stop their activities in usual life situations. It is assumed that patients with additional back pain will have more problems in managing the complete walking distance and therefore may stop the walking distance test before the endpoint at 15 minutes
Assessment of Neurological Status Using the Laségue Test or Straight Leg Raise Test- Change From Baseline to 24 Months	Baseline, Day 0 (Surgery), 3, 12, and 24 months	The straight leg raise or a Laségue Test is used to assess a participant's low back pain. A positive outcome is identified if a participant experiences low back pain when the straight leg is at a certain angle (0-90 degrees). A negative test suggests a likely different cause for back pain. The test is performed on both right and left legs.

Trial Locations

Locations (8): Oberlinklinik Potsdam Orthopädische Fachklinik
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Potsdam, Brandenburg, Germany
Orthopädische Universitätsklinik Frankfurt a.M.
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Frankfurt a.M., Hesse, Germany
Klinikum Ingolstadt Neurochirurgie
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Ingolstadt, Germany
Chirurgische Universitätsklinik Rostock Neurochirurgie
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Rostock, Mecklenburg-Western Pomerania, Germany
Otto-von-Guericke-Universität Magdeburg Klinik für Orthopädie
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Magdeburg, Saxony-Anhalt, Germany
Ostseeklinik Damp Neurochirurgie
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Damp, Schleswig-Holstein, Germany
Klinik für Wirbelsäulenchirurgie mit Skoliosezentrum Klinikum Neustadt
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Neustadt, Schleswig-Holstein, Germany
Klinik für Neurochirurgie Lübeck
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Lübeck, Schleswig-Holstein, Germany