Trial Outcomes & Findings for Clinical Trial Comparing Decompression With and Without Coflex™ Interlaminar Technology Treating Lumbar Spinal Stenosis (NCT NCT01316211)

Last Updated: 2020-06-09

Results Overview

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).

Recruitment status

COMPLETED

Study phase

Target enrollment

246 participants

Primary outcome timeframe

Baseline, 3, 12, and 24 months

Results posted on

2020-06-09

Participant Flow

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.

Participant milestones

Participant milestones
Measure	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.	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
Overall Study STARTED	116	123
Overall Study COMPLETED	105	111
Overall Study NOT COMPLETED	11	12

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Coflex™ n=116 Participants 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.	Surgical Decompression n=123 Participants 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	Total n=239 Participants Total of all reporting groups
Age, Continuous	68 years STANDARD_DEVIATION 9 • n=116 Participants	68 years STANDARD_DEVIATION 8 • n=123 Participants	68 years STANDARD_DEVIATION 8.8 • n=239 Participants
Sex: Female, Male Female	65 Participants n=116 Participants	61 Participants n=123 Participants	126 Participants n=239 Participants
Sex: Female, Male Male	51 Participants n=116 Participants	62 Participants n=123 Participants	113 Participants n=239 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment Germany	116 participants n=116 Participants	123 participants n=123 Participants	239 participants n=239 Participants
Weight	84 kg STANDARD_DEVIATION 15 • n=116 Participants	84 kg STANDARD_DEVIATION 17 • n=123 Participants	84 kg STANDARD_DEVIATION 16.1 • n=239 Participants
Height	170 cm STANDARD_DEVIATION 9 • n=116 Participants	170 cm STANDARD_DEVIATION 9 • n=123 Participants	170 cm STANDARD_DEVIATION 9.4 • n=239 Participants
BMI	29.0 kg/m^2 STANDARD_DEVIATION 4.3 • n=116 Participants	29.1 kg/m^2 STANDARD_DEVIATION 4.7 • n=123 Participants	29 kg/m^2 STANDARD_DEVIATION 4.6 • n=239 Participants

PRIMARY outcome

Timeframe: Baseline, 3, 12, and 24 months

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Change in ODI From Baseline to 24 Months	-19.0 percentage points Standard Deviation 2.1	-22.5 percentage points Standard Deviation 2.2

SECONDARY outcome

Timeframe: 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).

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	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
Number of Participants With Significant Migration or Expulsion of the Implant	2 Participants	—

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Change in Visual Analog Scale (VAS) Back Pain From Baseline to 24 Months	-23.5 mm Standard Deviation 2.8	-23.1 mm Standard Deviation 2.7

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Change in Visual Analog Scale (VAS) Leg Pain From Baseline to 24 Months	-24.3 mm Standard Deviation 2.5	-20.6 mm Standard Deviation 2.3

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Neurological Status - Mean Change in Sensory Deficit From Baseline to 24 Months	0.03 score on a scale Standard Deviation 0.01	0.04 score on a scale Standard Deviation 0.01

SECONDARY outcome

Timeframe: 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

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Assessment of Time to Symptoms Utilizing Walking Distance Test	6.01 minutes Standard Deviation 0.65	4.36 minutes Standard Deviation 0.64

SECONDARY outcome

Timeframe: 2 years

Number of Participants that experience adverse events related to the operative site from each group.

Outcome measures

Outcome measures
Measure	Coflex™ n=116 Participants 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.	Surgical Decompression n=123 Participants 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
Number of Participants With Adverse Events - Operative Site	45 Participants	54 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=116 Participants 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.	Surgical Decompression n=123 Participants 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
The Percentage of Patients With Survival Probability as Assessed by Evaluating Treatment Failure in Both Groups..	0.79 percentage of participants Interval 0.7 to 0.85	0.76 percentage of participants Interval 0.68 to 0.83

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Change of Symptoms- Zurich Claudication Questionnaire (ZCQ) After 24 Months Compared to Baseline.	-15.0 percentage points Standard Deviation 1.83	-15.10 percentage points Standard Deviation 1.75

SECONDARY outcome

Timeframe: Baseline, 3, 12, and 24 months

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Change in Functionality- Zurich Claudication Questionnaire (ZCQ) From Baseline to 24 Months	-3.98 percentage points Standard Deviation 0.38	-3.52 percentage points Standard Deviation 0.37

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Neurological Status - Mean Change in Muscle Strength From Baseline to 24 Months	0.002 score on a scale Standard Deviation 0.035	-0.030 score on a scale Standard Deviation 0.034

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
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	9.6 Degrees Standard Deviation 1.6

SECONDARY outcome

Timeframe: 2 years

Epidural injections at up to 24 months

Outcome measures

Outcome measures
Measure	Coflex™ n=116 Participants 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.	Surgical Decompression n=123 Participants 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
Number of Participants Receiving Epidural Injections	0 Participants	2 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Neurological Status- Mean Change in Trendelenburg Sign Test From Baseline to 24 Months.	-0.08 score on a scale Standard Deviation 0.36	-0.05 score on a scale Standard Deviation 0.29

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure	Coflex™ n=105 Participants 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.	Surgical Decompression n=111 Participants 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
Neurological Status- Mean Change in Ilio Sacral Joint Affection Test From Baseline to 24 Months.	-0.10 score on a scale Standard Deviation .43	-0.07 score on a scale Standard Deviation .45

Adverse Events

Coflex™

Serious events: 89 serious events

Other events: 89 other events

Deaths: 1 deaths

Surgical Decompression

Serious events: 96 serious events

Other events: 96 other events

Deaths: 1 deaths

Serious adverse events

Other adverse events

Additional Information

Fran Magee, DVM

Paradigm Spine

Phone: 212-367-7274

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Serious adverse events
Measure	Coflex™ n=116 participants at risk 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.	Surgical Decompression n=123 participants at risk 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
Gastrointestinal disorders Gastritis	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders Coxarthrosis	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures Coronary Stent	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	3.3% 4/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Nervous system disorders APOPLECTIC STROKE ARTERIA CEREBRI MEDIA RIGHT	1.7% 2/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders ARRYTHMIA ABSOLUTA	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) BREAST CANCER	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders CARDIAC ARRHYTHMIA	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders CARDIAC STENT	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Eye disorders CATARACT LEFT EYE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders CERVICAL DISC HERNIATION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Gastrointestinal disorders COLITIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.81% 1/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Gastrointestinal disorders STOMACH POLYP	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders FACET PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications FALL	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures FRACTURE PROXIMAL HUMERUS SURGERY (PLATE)	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures FUSION C5/C6	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
General disorders GENERAL WEAKNESS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders HEART ATTACK	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders HIP ARTHROSIS LEFT	1.7% 2/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures HIP SURGERY, KNOWN COXARTHROSIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures IMPLANTATION CORONARY STENT	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures IMPLANTATION OF TEP LEFT HIP	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures KNEE PAIN AND SURGERY LEFT 08 JUN 2011	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders LEG PAIN RIGHT (GLUTEAL PAIN RIGHT SIDE)	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures LENS EXCHANGE RIGHT EYE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders LUMBAR BACK PAIN L5/S1 AND L3/L4	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications MILD HEAD INJURY	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Nervous system disorders MYASTHENIA GRAVIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) MYELODYSPLASIA	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders MYELOPATHY CERVICULAR WITH SPONDYLODESIS C3/4	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders MYOCARDIAL INFARCTION	1.7% 2/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications NASAL SEPTUM DEVIATION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Renal and urinary disorders NEPHROLITHIASIS LEFT	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Surgical and medical procedures PACE-MAKER-IMPLANTATION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications PATIENT FELL DOWN, CONTUSION OF RIGHT FEMUR AND HIP	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Vascular disorders PERIPHERAL ARTERIAL DISEASE BOTH LEGS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PNEUMONIA	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PNEUMONIA WITH RENAL FAILURE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Psychiatric disorders PSYCHOTIC SYNDROME	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Eye disorders PUPIL INFARCTION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.

Other adverse events
Measure	Coflex™ n=116 participants at risk 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.	Surgical Decompression n=123 participants at risk 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
Injury, poisoning and procedural complications TRAUMA FALL	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PAIN; NEW, AND FREQUENCY, WORSENING - BOTH LEG AND BACK BACK PAIN, POSSIBLE BECAUSE OF KNEE PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders CEREBROSPINAL FLUID LEAKAGE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders LOCAL OSTEOPOROSIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PAIN; NEW, AND FREQUENCY, WORSENING - BACK INCREASING BACK PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders DISC HERNIATION DISC PROLAPS L4/5	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications TRAUMA BACK PAIN AFTER FALL	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders SACROILIAC JOINT PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Infections and infestations WOUND PROBLEMS	5.2% 6/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	4.1% 5/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications DURAL VIOLATION	2.6% 3/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	15.4% 19/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PAIN; NEW, AND FREQUENCY, WORSENING - BACK INCREASING LUMBAGO	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PAIN; NEW, AND FREQUENCY, WORSENING - BOTH LEG AND BACK LUMBOISCHIALGIA LEFT	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications COMPONENT MIGRATION DORSAL MIGRATION OF COFLEX	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders FRACTURE, SPECIFY: TIIP OF SPINOUS PROCESS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Respiratory, thoracic and mediastinal disorders PROGRESSIVE OSTEOCHONDROSIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications FRACTURE, SPECIFY: FISSURE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications DURAL VIOLATION L5/S1	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders COXALGIA LEFT	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Nervous system disorders VERTIGO	0.00% 0/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	1.6% 2/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications FALL WITH FOLLOWING BACK PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders TROCHANTER PAIN BOTH SIDES RESP. PELVIC + HIP PAIN BOTH SIDES	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders HIP PAIN	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.81% 1/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders KNEE PAIN BOTH SIDES	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders PAIN KNEE	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Renal and urinary disorders RENAL INSUFFICIENCY	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Gastrointestinal disorders INFECTION INTESTINAL WITH CLOSTRIDIA	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders GONARTHROSIS BOTH	1.7% 2/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Nervous system disorders DISORIENTATION CEREBRAL	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders PAIN RIGHT HIP	2.6% 3/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.81% 1/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders SHOULDER PAIN	1.7% 2/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.81% 1/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Renal and urinary disorders BLADDER DYSFUNCTION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Blood and lymphatic system disorders EDEMA LOWER LEGS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Cardiac disorders ANGINA PECTORIS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders GONARTHROSIS ACTIVATED	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders CORPUS VITREUM RETRACTION	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Musculoskeletal and connective tissue disorders CRAMPS IN THIGHS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Psychiatric disorders SYMPTOMATIC TRANSITORY PSYCHOTIC SYNDROME	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
General disorders DIZZINESS	0.00% 0/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.81% 1/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Endocrine disorders DIABETES MELLITUS	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.
Injury, poisoning and procedural complications MUSCLE INJURY LEFT GLUTEAL	0.86% 1/116 • 24 months Adverse events were captured at either the operative site or non-operative site.	0.00% 0/123 • 24 months Adverse events were captured at either the operative site or non-operative site.