Spinal Stenosis
Conditions
Keywords
Back Pains, Pain, Back, Pains, Back, Backache, Backaches, Back Ache, Ache, Back, Aches, Back, Back Aches, Back Pain without Radiation, Vertebrogenic Pain Syndrome, Pain Syndrome, Vertebrogenic, Pain Syndromes, Vertebrogenic, Syndrome, Vertebrogenic Pain, Syndromes, Vertebrogenic Pain, Vertebrogenic Pain Syndromes, Back Pain with Radiation, Stenosis, spinal, Caudal stenosis, Spondylopathy, Spondylopathies, Low back pain, Lower back pain
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.
Interventions
DEVICEImplantation of coflex™ after surgical decompression
The device will be implanted after surgical decompression in patients with spinal stenosis.
PROCEDURESurgical decompression
Surgical decompression in patients with spinal stenosis without stabilization by an additional implant
Sponsors
MDT Medical Device Testing GmbH
MCRA
Paradigm Spine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. 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. 2. Radiographic confirmation of no translatory instability in the main segment as well as in adjacent segments (dynamic translatory instability ≤ 3 mm). 3. 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). 4. Minimum of 3 months conservative therapy without improvement of symptoms. 5. Age \>40 years. 6. 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). 7. Suitability of the patient for a posterior surgery procedure. 8. 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. 9. 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: 1. Preceding fusion or decompression surgery of the lumbar spine or preceding nucleotomy of the segments of concern (also if nucleotomy becomes necessary during surgery). 2. 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) 3. Isthmic and degenerative spondylolisthesis (anterolisthesis; retrolisthesis \> grade I) or spondylolysis (Pars fracture). 4. Degenerative lumbar scoliosis (\> 25°). 5. Adipositas (obesity). Defined as a body mass index \>40. 6. Pregnancy, or wish to get pregnant during the course of the study. 7. Known allergy for titanium and titanium alloys. 8. Fluoride infections - both systemic and local. 9. History of severe peripheral neuropathy. 10. Significant peripheral vascular disease (claudication intermittens ≥ stage 2b). 11. M. Paget or osteomalacia or other metabolic bone disorders. 12. Cauda equina syndrome. 13. Communicating diseases, including HIV, active hepatitis 14. Patients who are lawfully kept in an institution. 15. 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. 16. Subjects who participated in a clinical observation or therapy with X-ray during the last 10 years. 17. Subjects who participate(d) in another clinical trial (within the last 4 weeks) that might influence the safety and effectiveness assessment of this trial.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
| 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 |
| 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. |
| 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. |
| 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 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. |
| 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. |
| 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. |
| 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. |
| 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 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. |
Countries
Germany
Participant flow
Pre-assignment details
120 patients in the Coflex group and 126 in the control group underwent surgery. 4 Coflex patients and 3 Control patients had to be excluded from full-analysis population, since no follow-up values were recorded and the reason of drop-out did not indicate treatment failure.
Participants by arm
| Arm | Count |
|---|---|
| Coflex™ Implantation of coflex™ device in assigned patients
Implantation of coflex™ after surgical decompression: The device will be implanted after surgical decompression in patients with spinal stenosis. | 116 |
| Surgical Decompression Surgical decompression in patients with spinal stenosis without stabilization by an additional implant.
Surgical decompression: Surgical decompression in patients with spinal stenosis without stabilization by an additional implant | 123 |
| Total | 239 |
Baseline characteristics
| Characteristic | Coflex™ | Surgical Decompression | Total |
|---|---|---|---|
| Age, Continuous | 68 years STANDARD_DEVIATION 9 | 68 years STANDARD_DEVIATION 8 | 68 years STANDARD_DEVIATION 8.8 |
| BMI | 29.0 kg/m^2 STANDARD_DEVIATION 4.3 | 29.1 kg/m^2 STANDARD_DEVIATION 4.7 | 29 kg/m^2 STANDARD_DEVIATION 4.6 |
| Height | 170 cm STANDARD_DEVIATION 9 | 170 cm STANDARD_DEVIATION 9 | 170 cm STANDARD_DEVIATION 9.4 |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Region of Enrollment Germany | 116 participants | 123 participants | 239 participants |
| Sex: Female, Male Female | 65 Participants | 61 Participants | 126 Participants |
| Sex: Female, Male Male | 51 Participants | 62 Participants | 113 Participants |
| Weight | 84 kg STANDARD_DEVIATION 15 | 84 kg STANDARD_DEVIATION 17 | 84 kg STANDARD_DEVIATION 16.1 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 1 / 116 | 1 / 123 |
| other Total, other adverse events | 89 / 116 | 96 / 123 |
| serious Total, serious adverse events | 89 / 116 | 96 / 123 |
Outcome results
Primary
Change in ODI From Baseline to 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).
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Change in ODI From Baseline to 24 Months | -19.0 percentage points | Standard Deviation 2.1 |
| Surgical Decompression | Change in ODI From Baseline to 24 Months | -22.5 percentage points | Standard Deviation 2.2 |
Secondary
Assessment of Neurological Status Using the Laségue Test or Straight Leg Raise Test- Change From Baseline to 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.
Time frame: Baseline, Day 0 (Surgery), 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Assessment of Neurological Status Using the Laségue Test or Straight Leg Raise Test- Change From Baseline to 24 Months | 10.8 Degrees | Standard Deviation 1.6 |
| Surgical Decompression | Assessment of Neurological Status Using the Laségue Test or Straight Leg Raise Test- Change From Baseline to 24 Months | 9.6 Degrees | Standard Deviation 1.6 |
Secondary
Assessment of Time to Symptoms Utilizing Walking Distance Test
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
Time frame: 2 years
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Assessment of Time to Symptoms Utilizing Walking Distance Test | 6.01 minutes | Standard Deviation 0.65 |
| Surgical Decompression | Assessment of Time to Symptoms Utilizing Walking Distance Test | 4.36 minutes | Standard Deviation 0.64 |
Secondary
Change in Functionality- Zurich Claudication Questionnaire (ZCQ) From Baseline to 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.
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Change in Functionality- Zurich Claudication Questionnaire (ZCQ) From Baseline to 24 Months | -3.98 percentage points | Standard Deviation 0.38 |
| Surgical Decompression | Change in Functionality- Zurich Claudication Questionnaire (ZCQ) From Baseline to 24 Months | -3.52 percentage points | Standard Deviation 0.37 |
Secondary
Change in Visual Analog Scale (VAS) Back Pain From Baseline to 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.
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Change in Visual Analog Scale (VAS) Back Pain From Baseline to 24 Months | -23.5 mm | Standard Deviation 2.8 |
| Surgical Decompression | Change in Visual Analog Scale (VAS) Back Pain From Baseline to 24 Months | -23.1 mm | Standard Deviation 2.7 |
Secondary
Change in Visual Analog Scale (VAS) Leg Pain From Baseline to 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.
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Change in Visual Analog Scale (VAS) Leg Pain From Baseline to 24 Months | -24.3 mm | Standard Deviation 2.5 |
| Surgical Decompression | Change in Visual Analog Scale (VAS) Leg Pain From Baseline to 24 Months | -20.6 mm | Standard Deviation 2.3 |
Secondary
Change of Symptoms- Zurich Claudication Questionnaire (ZCQ) After 24 Months Compared to Baseline.
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.
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Change of Symptoms- Zurich Claudication Questionnaire (ZCQ) After 24 Months Compared to Baseline. | -15.0 percentage points | Standard Deviation 1.83 |
| Surgical Decompression | Change of Symptoms- Zurich Claudication Questionnaire (ZCQ) After 24 Months Compared to Baseline. | -15.10 percentage points | Standard Deviation 1.75 |
Secondary
Neurological Status- Mean Change in Ilio Sacral Joint Affection Test From Baseline to 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.
Time frame: Baseline, Day 0 (Surgery), 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Neurological Status- Mean Change in Ilio Sacral Joint Affection Test From Baseline to 24 Months. | -0.10 score on a scale | Standard Deviation 0.43 |
| Surgical Decompression | Neurological Status- Mean Change in Ilio Sacral Joint Affection Test From Baseline to 24 Months. | -0.07 score on a scale | Standard Deviation 0.45 |
Secondary
Neurological Status - Mean Change in Muscle Strength From Baseline to 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.
Time frame: Baseline, Day 0 (Surgery), 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Neurological Status - Mean Change in Muscle Strength From Baseline to 24 Months | 0.002 score on a scale | Standard Deviation 0.035 |
| Surgical Decompression | Neurological Status - Mean Change in Muscle Strength From Baseline to 24 Months | -0.030 score on a scale | Standard Deviation 0.034 |
Secondary
Neurological Status - Mean Change in Sensory Deficit From Baseline to 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.
Time frame: Baseline, 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Neurological Status - Mean Change in Sensory Deficit From Baseline to 24 Months | 0.03 score on a scale | Standard Deviation 0.01 |
| Surgical Decompression | Neurological Status - Mean Change in Sensory Deficit From Baseline to 24 Months | 0.04 score on a scale | Standard Deviation 0.01 |
Secondary
Neurological Status- Mean Change in Trendelenburg Sign Test From Baseline to 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.
Time frame: Baseline, Day 0 (Surgery), 3, 12, and 24 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Coflex™ | Neurological Status- Mean Change in Trendelenburg Sign Test From Baseline to 24 Months. | -0.08 score on a scale | Standard Deviation 0.36 |
| Surgical Decompression | Neurological Status- Mean Change in Trendelenburg Sign Test From Baseline to 24 Months. | -0.05 score on a scale | Standard Deviation 0.29 |
Secondary
Number of Participants Receiving Epidural Injections
Epidural injections at up to 24 months
Time frame: 2 years
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Coflex™ | Number of Participants Receiving Epidural Injections | 0 Participants |
| Surgical Decompression | Number of Participants Receiving Epidural Injections | 2 Participants |
Secondary
Number of Participants With Adverse Events - Operative Site
Number of Participants that experience adverse events related to the operative site from each group.
Time frame: 2 years
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Coflex™ | Number of Participants With Adverse Events - Operative Site | 45 Participants |
| Surgical Decompression | Number of Participants With Adverse Events - Operative Site | 54 Participants |
Secondary
Number of Participants With Significant Migration or Expulsion of the Implant
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).
Time frame: 2 years
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Coflex™ | Number of Participants With Significant Migration or Expulsion of the Implant | 2 Participants |
Secondary
The Percentage of Patients With Survival Probability as Assessed by Evaluating Treatment Failure in Both Groups..
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.
Time frame: 2 years
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Coflex™ | The Percentage of Patients With Survival Probability as Assessed by Evaluating Treatment Failure in Both Groups.. | 0.79 percentage of participants |
| Surgical Decompression | The Percentage of Patients With Survival Probability as Assessed by Evaluating Treatment Failure in Both Groups.. | 0.76 percentage of participants |