Cervical Degenerative Disc Disease
Conditions
Keywords
Cervical, Disc, Arthroplasty, Spinal
Brief summary
The purpose of the study is to evaluate the performance of the Discover cervical Artificial disc in the treatment of degenerative disc disease in one level of the cervical spine.
Detailed description
The protocol underwent 3 amendments, the last of which (02APR2009) changed the study design from a randomized to a non-randomized and non-comparative clinical trial. All of the subjects were enrolled under the randomized design with the exception of the last subject. This study is not applicable per FDAA Title VIII, Section 801 due to the final trial design. However, results are submitted to clinicaltrials.gov due to the majority of study data being collected under a randomized (FDAA Title VIII, Section 801 applicable) trial design
Interventions
DEVICEDISCOVER™ Artificial Cervical Disc
DISCOVER™ Artificial Cervical Disc
DEVICEACDF
Cervical CFRP I/F CAGE® and SLIM LOC(R) Anterior Cervical Plate System with allograft
Sponsors
DePuy International
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Male or female subjects, aged between 18 and 65 years inclusive. * Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained. * Subjects who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, co-operate with the investigational procedures and are willing to return to the hospital for all the required post-operative follow-ups. * Objective evidence of cervical disc disease in one vertebral level between C3-C7 defined as one or more of the following: * Shoulder and/or arm pain in a radicular distribution resulting from herniated disc or bony osteophytes (Consistent w diagnostic imaging including Axial CT, CT Myelogram, MRI and/or plain films) * Subjects with myeloradiculopathy resulting from mild spinal cord compression and nerve root impingement * Unresponsive to documented non-surgical management for ≥ 6 weeks and/or presents with progressive symptoms of nerve root or spinal cord compression in the face of continued non-surgical management (e.g., physical therapy, medication therapy, corticosteroid injections, etc.) * Minimum Neck Disability Index score of ≥30 % (15/50 points)
Exclusion criteria
* Subjects who, in the opinion of the Clinical Investigator, have an existing condition that would compromise their participation and follow-up in this clinical investigation. * Subjects who are pregnant, lactating or wishes to become pregnant within the duration of the study. * Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes. * Subjects who have participated in a clinical investigation with an investigational product in the last 30 days. * Subjects who are currently involved in any injury litigation claims. * Subjects with significant degeneration at more than one cervical level (e.g. DISH, ankylosing spondylitis, congenital abnormality, rheumatoid arthritis) * Subjects who have had any prior surgery at the level to be treated (subjects with a prior Laminotomy at the level to be treated may be included in the study) * Subjects who have marked cervical instability on lateral or flexion/extension x-rays defined as translation ≥3mm and/or ≥11 degrees of rotational difference to either adjacent level * Subjects who have presence of systemic infection or infection at the site of surgery * Subjects who have been diagnosed with malignancy * Subjects who have been diagnosed with a condition or require postoperative medication(s) that may interfere with bony/soft tissue healing * Subjects who have been diagnosed with Osteoporosis, Osteopenia, other metabolic bone disease or endocrine disorder known to affect osteogenesis. * Subjects with pre-existing neurological abnormalities other than deficits produced from the spinal lesion (e.g., MS, Parkinson's, CVA, diabetic neuropathy, peripheral neuropathy). * Subjects with morbid obesity defined as a BMI of ≥40, or more than 100 lbs (45.4kg) over ideal weight. * Subjects with any known allergy to titanium metal, polyethylene, metal alloy or carbon fibre reinforced polymer * Subjects who have had prior fusion surgery at any level(s) (C1-T1) * Subjects with kyphosis \>-15 degrees evaluated using the Cobb angle measurement * Subjects with Significant cervical degenerative disease characterized by bridging anterior osteophytes, significant loss of disc space height (3mm or less), sclerotic facets, large posterior osteophytes, autofusion of other cervical levels, and degenerative retrolisthesis. Spinal diseases such as DISH, ankylosing spondylitis, congenital abnormality, and rheumatoid arthritis, should also be excluded * Subjects undergoing treatment with a bone growth stimulator, which cannot be discontinued prior to enrollment in the study. * Significant kyphotic deformity or significant reversal of lordosis.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Overall Patient Success | 12 months | Overall success was a composite endpoint determined by the following clinical outcome measures: 1. Neck Disability Index ≥ 15-point improvement from baseline to 12 months post-operative, 2. No new clinically significant permanent abnormalities in neurological function (i.e. motor strength, nerve root tension signs, sensory and reflex signs) from baseline to 12 months post-operative, 3. No subsequent secondary surgical interventions (SSI) at the index level, and 4. No device-related serious events (dSAE) from intra-operative through 12-months post-operative. Please note that these time periods were intended to be from baseline to 24 months post-operative, but since the study was terminated early the 12 month time periods were utilized. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Visual Analogue Scale (VAS) Left Arm Pain From Pre-treatment to 12 Months. | 12 Months | The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their left arm. |
| Change in Visual Analogue Scale (VAS) Right Arm Pain From Pre-treatment to 12 Months. | 12 Months | The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0= 0 cm) listed on the left and 'Very severe pain' (score of 100= 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their right arm. |
| Change in Visual Analogue Scale (VAS) Right Shoulder Pain From Pre-treatment to 12 Months. | 12 Months | The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their right shoulder. |
| Change in Visual Analogue Scale (VAS) Left Shoulder Pain From Pre-treatment to 12 Months. | 12 Months | The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 10 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their left shoulder. |
| Change in Mental Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 12 months | The 36-item Short Form Health Survey (SF-36) is a patient reported outcome survey that evaluates functional health and well-being. The survey is converted into 2 summary measures that are scored from 0 to 100 (where 100 indicates the highest level of health) - the Physical Component Score (PCS-36) and Mental Component Score (MCS-36) |
| Change in Function Assessed by Neck Disability Index Improvement From Pre-treatment to 12 Months | 12 months | The neck disability index (NDI) is a validated, disease specific, self-administrated questionnaire for assessing pain intensity and function in patients with neck pain on a scale from 0 to 100. A lower score is a better result (i.e. less severe pain and/or better function). The proportion of patients with an improved score (lower) of 15 points or more was the analysis variable. |
| Change in Physical Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 12 months | The 36-item Short Form Health Survey (SF-36) is a patient reported outcome survey that evaluates functional health and well-being. The survey is converted into 2 summary measures that are scored from 0 to 100 (where 100 indicates the highest level of health) - the Physical Component Score (PCS-36) and Mental Component Score (MCS-36) |
| Change in Visual Analogue Scale (VAS) Neck Pain From Pre-treatment to 12 Months | 12 months | The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their neck. |
| Sagittal Angulation, Also Known as Global Lordosis, Measured Radiographically at 6 Months | 6 months | Sagittal Angulation is a measure of the angle formed between the inferior endplate of the C2 vertebrae and the corresponding inferior endplate of vertebrae C7 of the spine, measured in degrees, from a side (sagittal) view. |
| Adjacent Level Degeneration Measured Radiographically at 24 Months | 24 months | Adjacent Level Degeneration is evaluated using a point system that assigns numerical scores to severity of Height Loss, Anterior Osteophytes, and Endplate Sclerosis; and then grades into one of the following five categories: None, Mild, Moderate, Severe, or NA. |
| Maintenance of Disc Height Measured Radiographically at 6 Months | 6 months | Maintenance of disc height is measured at the index and adjacent levels to determine the effect of the treatment on restoration or maintenance of the disc height. Initial post-operative disc height is compared with subsequent post-operative visits (i.e. 6 months) to evaluate the maintenance of disc height. The height is measured in millimeters (mm). |
| Foraminal Height Measured Radiographically at 24 Months | 24 months | Foraminal height is the maximum vertical distance, measured in millimeters (mm), between the inferior surface of the superior pedicle and superior surface of the inferior pedicle. These measurements are obtained via magnetic resonance imaging (MRI). |
| Cervical Range of Motion Measured Radiographically at 6 Months | 6 months | Cervical range of motion measures the angle, in degrees, between the inferior endplate of C2 to the inferior endplate of C7 on flexion-extension radiographs. |
| Device Related Adverse Events | Intra-operatively to 24 months post-operative | The proportion of subjects with device related adverse events as reported throughout the duration of the study. |
| Work Status Assessed at 12 Months | 12 months | The proportion of subjects with unrestricted work status (compared to subjects not working or with restricted work status) is reported at the 12 month follow-up interval. |
Countries
Australia, Germany, Italy, Malaysia, Netherlands, Spain, United Kingdom
Participant flow
Recruitment details
5 sites enrolled 60 subjects who were randomized into two treatment groups. Site 12 (17 subjects total) transferred into the Discover IDE study. Site 04 (5 subjects total) did not submit data, which was limited, due to EDC technical difficulties at the site. Therefore 38 subjects are reported in this study.
Participants by arm
| Arm | Count |
|---|---|
| Cervical Total Disc Replacement DISCOVER™ Artificial Cervical Disc | 22 |
| ACDF Anterior Cervical Discectomy and Fusion (ACDF) | 16 |
| Total | 38 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 4 | 4 |
Baseline characteristics
| Characteristic | Cervical Total Disc Replacement | ACDF | Total |
|---|---|---|---|
| Age, Continuous | 45.3 years STANDARD_DEVIATION 8.87 | 47.5 years STANDARD_DEVIATION 8.17 | 46.2 years STANDARD_DEVIATION 8.65 |
| Region of Enrollment Germany | 0 participants | 1 participants | 1 participants |
| Region of Enrollment Spain | 2 participants | 1 participants | 3 participants |
| Region of Enrollment United Kingdom | 20 participants | 14 participants | 34 participants |
| Sex: Female, Male Female | 11 Participants | 11 Participants | 22 Participants |
| Sex: Female, Male Male | 11 Participants | 5 Participants | 16 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 9 / 22 | 6 / 16 |
| serious Total, serious adverse events | 3 / 22 | 1 / 16 |
Outcome results
Primary
Overall Patient Success
Overall success was a composite endpoint determined by the following clinical outcome measures: 1. Neck Disability Index ≥ 15-point improvement from baseline to 12 months post-operative, 2. No new clinically significant permanent abnormalities in neurological function (i.e. motor strength, nerve root tension signs, sensory and reflex signs) from baseline to 12 months post-operative, 3. No subsequent secondary surgical interventions (SSI) at the index level, and 4. No device-related serious events (dSAE) from intra-operative through 12-months post-operative. Please note that these time periods were intended to be from baseline to 24 months post-operative, but since the study was terminated early the 12 month time periods were utilized.
Time frame: 12 months
Population: Overall Patient Success is composed of several outcome measures, some of which require a valid pre-operative and 12-month post-operative score. Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for the Overall Patient Success calculation.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Cervical Total Disc Replacement | Overall Patient Success | 33.33 Percentage of subjects |
| ACDF | Overall Patient Success | 90.91 Percentage of subjects |
Secondary
Adjacent Level Degeneration Measured Radiographically at 24 Months
Adjacent Level Degeneration is evaluated using a point system that assigns numerical scores to severity of Height Loss, Anterior Osteophytes, and Endplate Sclerosis; and then grades into one of the following five categories: None, Mild, Moderate, Severe, or NA.
Time frame: 24 months
Population: Study was terminated prior to 24 months therefore there are no results for this endpoint.
Secondary
Cervical Range of Motion Measured Radiographically at 6 Months
Cervical range of motion measures the angle, in degrees, between the inferior endplate of C2 to the inferior endplate of C7 on flexion-extension radiographs.
Time frame: 6 months
Population: Only 2 subjects in the cTDR and 2 subjects in the ACDF treatment groups were available for this outcome measure.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Cervical Range of Motion Measured Radiographically at 6 Months | 53.9 degrees | Standard Deviation 16.4 |
| ACDF | Cervical Range of Motion Measured Radiographically at 6 Months | 55.2 degrees | Standard Deviation 25.5 |
Secondary
Change in Function Assessed by Neck Disability Index Improvement From Pre-treatment to 12 Months
The neck disability index (NDI) is a validated, disease specific, self-administrated questionnaire for assessing pain intensity and function in patients with neck pain on a scale from 0 to 100. A lower score is a better result (i.e. less severe pain and/or better function). The proportion of patients with an improved score (lower) of 15 points or more was the analysis variable.
Time frame: 12 months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Cervical Total Disc Replacement | Change in Function Assessed by Neck Disability Index Improvement From Pre-treatment to 12 Months | 33.33 Percentage of Subjects |
| ACDF | Change in Function Assessed by Neck Disability Index Improvement From Pre-treatment to 12 Months | 90.91 Percentage of Subjects |
Secondary
Change in Mental Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months
The 36-item Short Form Health Survey (SF-36) is a patient reported outcome survey that evaluates functional health and well-being. The survey is converted into 2 summary measures that are scored from 0 to 100 (where 100 indicates the highest level of health) - the Physical Component Score (PCS-36) and Mental Component Score (MCS-36)
Time frame: 12 months
Population: Due to withdrawals and incomplete or unavailable assessments, 16 subjects in the CTDR and 10 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Mental Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 4.1 units on a scale | Standard Deviation 13.2 |
| ACDF | Change in Mental Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 15.1 units on a scale | Standard Deviation 14 |
Secondary
Change in Physical Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months
The 36-item Short Form Health Survey (SF-36) is a patient reported outcome survey that evaluates functional health and well-being. The survey is converted into 2 summary measures that are scored from 0 to 100 (where 100 indicates the highest level of health) - the Physical Component Score (PCS-36) and Mental Component Score (MCS-36)
Time frame: 12 months
Population: Due to withdrawals and incomplete or unavailable assessments, 16 subjects in the CTDR and 10 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Physical Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 8.1 units on a scale | Standard Deviation 11.7 |
| ACDF | Change in Physical Component Summary Quality of Life Measure Assessed by Short Form SF-36 From Pre-treatment to 12 Months | 17.7 units on a scale | Standard Deviation 9.2 |
Secondary
Change in Visual Analogue Scale (VAS) Left Arm Pain From Pre-treatment to 12 Months.
The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their left arm.
Time frame: 12 Months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Visual Analogue Scale (VAS) Left Arm Pain From Pre-treatment to 12 Months. | -15.9 units on a scale | Standard Deviation 25.7 |
| ACDF | Change in Visual Analogue Scale (VAS) Left Arm Pain From Pre-treatment to 12 Months. | -46.6 units on a scale | Standard Deviation 43.5 |
Secondary
Change in Visual Analogue Scale (VAS) Left Shoulder Pain From Pre-treatment to 12 Months.
The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 10 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their left shoulder.
Time frame: 12 Months
Population: Due to withdrawals and incomplete or unavailable assessments, 17 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Visual Analogue Scale (VAS) Left Shoulder Pain From Pre-treatment to 12 Months. | -17.1 units on a scale | Standard Deviation 28.9 |
| ACDF | Change in Visual Analogue Scale (VAS) Left Shoulder Pain From Pre-treatment to 12 Months. | -49.8 units on a scale | Standard Deviation 36.5 |
Secondary
Change in Visual Analogue Scale (VAS) Neck Pain From Pre-treatment to 12 Months
The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their neck.
Time frame: 12 months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Visual Analogue Scale (VAS) Neck Pain From Pre-treatment to 12 Months | -16.6 units on a scale | Standard Deviation 34.2 |
| ACDF | Change in Visual Analogue Scale (VAS) Neck Pain From Pre-treatment to 12 Months | -52.1 units on a scale | Standard Deviation 22.86 |
Secondary
Change in Visual Analogue Scale (VAS) Right Arm Pain From Pre-treatment to 12 Months.
The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0= 0 cm) listed on the left and 'Very severe pain' (score of 100= 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their right arm.
Time frame: 12 Months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Visual Analogue Scale (VAS) Right Arm Pain From Pre-treatment to 12 Months. | -18.4 units on a scale | Standard Deviation 32.8 |
| ACDF | Change in Visual Analogue Scale (VAS) Right Arm Pain From Pre-treatment to 12 Months. | -20.5 units on a scale | Standard Deviation 25.8 |
Secondary
Change in Visual Analogue Scale (VAS) Right Shoulder Pain From Pre-treatment to 12 Months.
The visual analogue scale (VAS) pain score asks the subject to place a vertical mark on a horizontal line (that is approximately 10 cm long) with 'No Pain' (score of 0 = 0 cm) listed on the left and 'Very severe pain' (score of 100 = 10 cm) labeled on the right. The subject is instructed to indicate the amount of pain they feel in their right shoulder.
Time frame: 12 Months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 11 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Change in Visual Analogue Scale (VAS) Right Shoulder Pain From Pre-treatment to 12 Months. | -15.7 units on a scale | Standard Deviation 35.4 |
| ACDF | Change in Visual Analogue Scale (VAS) Right Shoulder Pain From Pre-treatment to 12 Months. | -22.4 units on a scale | Standard Deviation 32.7 |
Secondary
Device Related Adverse Events
The proportion of subjects with device related adverse events as reported throughout the duration of the study.
Time frame: Intra-operatively to 24 months post-operative
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Cervical Total Disc Replacement | Device Related Adverse Events | 13.64 Percentage of subjects |
| ACDF | Device Related Adverse Events | 0.00 Percentage of subjects |
Secondary
Foraminal Height Measured Radiographically at 24 Months
Foraminal height is the maximum vertical distance, measured in millimeters (mm), between the inferior surface of the superior pedicle and superior surface of the inferior pedicle. These measurements are obtained via magnetic resonance imaging (MRI).
Time frame: 24 months
Population: The study was terminated prior to 24 months therefore there are no results for this endpoint.
Secondary
Maintenance of Disc Height Measured Radiographically at 6 Months
Maintenance of disc height is measured at the index and adjacent levels to determine the effect of the treatment on restoration or maintenance of the disc height. Initial post-operative disc height is compared with subsequent post-operative visits (i.e. 6 months) to evaluate the maintenance of disc height. The height is measured in millimeters (mm).
Time frame: 6 months
Population: Only 2 subjects in the cTDR and 1 subject in the ACDF treatment groups were available for this outcome measure. There were 2 ACDF subjects at this endpoint, however one subject was missing the flexion extension rotation radiographic view therefore could not be included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Maintenance of Disc Height Measured Radiographically at 6 Months | 4.7 mm | Standard Deviation 0.57 |
| ACDF | Maintenance of Disc Height Measured Radiographically at 6 Months | 5.1 mm | — |
Secondary
Sagittal Angulation, Also Known as Global Lordosis, Measured Radiographically at 6 Months
Sagittal Angulation is a measure of the angle formed between the inferior endplate of the C2 vertebrae and the corresponding inferior endplate of vertebrae C7 of the spine, measured in degrees, from a side (sagittal) view.
Time frame: 6 months
Population: Only 2 subjects in the Cervical Total Disc Replacement (cTDR) and 1 subject in the ACDF treatment groups were available for this outcome measure. There were 2 ACDF subjects at this endpoint, however one subject was missing the flexion extension rotation radiographic view therefore could not be included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cervical Total Disc Replacement | Sagittal Angulation, Also Known as Global Lordosis, Measured Radiographically at 6 Months | 9.6 degrees | Standard Deviation 10 |
| ACDF | Sagittal Angulation, Also Known as Global Lordosis, Measured Radiographically at 6 Months | -1.5 degrees | — |
Secondary
Work Status Assessed at 12 Months
The proportion of subjects with unrestricted work status (compared to subjects not working or with restricted work status) is reported at the 12 month follow-up interval.
Time frame: 12 months
Population: Due to withdrawals and incomplete or unavailable assessments, 18 subjects in the CTDR and 12 subjects in the ACDF treatment groups were available for this outcome.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Cervical Total Disc Replacement | Work Status Assessed at 12 Months | 38.89 Percentage of Subjects |
| ACDF | Work Status Assessed at 12 Months | 50.00 Percentage of Subjects |