Cervical Degenerative Disc Disease
Conditions
Keywords
cervical, spinal, arthroplasty, disc, surgical, ACDF, DDD
Brief summary
This study is intended to treat patients with symptomatic degenerative disc disease at one level of the cervical spine. The patients will be randomized to the DISCOVER Artificial Cervical Disc (total disc replacement) or SLIM-LOC™ (cervical fusion) to determine the safety and efficacy at 2 years post operative. Follow-up on patients treated with total disc replacement will be continued to 5 years post operative.
Detailed description
This study is designed as a multicenter, prospective, randomized, controlled trial. Subjects will be stratified by the number of levels to be treated then assigned treatment in a randomized 1:1 ratio. Participants in the treatment group will undergo cervical total disc replacement with the DISCOVER Artificial Cervical Disc. Participants in the control group will undergo anterior cervical discectomy and fusion with the SLIM-LOC™ Anterior Cervical Plate System with a cortical or cortico-cancellous allograft spacer. Follow-up visits will occur at 2 weeks, 3 and 6 months and 1, and 2 years for all randomized subjects. Subjects that received the control treatment will complete their required study participation at 2 years post operative and subjects assigned the Discover treatment will complete their participation at 5 years post operative. Follow-up for the Discover treatment group will be via a telephone administered questionnaire at 3, 4 and 5 years post operative.
Interventions
DEVICECervical TDR
Cervical total disc replacement using a DISCOVER Artificial Cervical Disc.
DEVICEACDF with plate
Anterior cervical discectomy followed by insertion of allograft spacer and placement of an anterior plate.
Sponsors
DePuy Spine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Participant was masked to which treatment they would receive until AFTER the surgery/treatment procedure. At that point, they were unmasked.
Eligibility
Sex/Gender
ALL
Age
21 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
Key Inclusion Criteria: * Objective evidence of cervical disc disease in 1 vertebral level between C3-C7 defined as (a) shoulder and/or arm pain in a documented radicular distribution resulting from herniated disc or bony osteophytes or (b)myeloradiculopathy resulting from mild spinal cord compression and nerve root impingement * Unresponsiveness to documented non-surgical management for greater than or equal to 6 weeks and/or presentation with progressive symptoms of nerve root or spinal cord compression in the face of continued non-surgical management * Moderate Neck Disability Index (NDI) score * Able to give informed consent for study participation * Able and willing to return for all follow-up visits Key
Exclusion criteria
* Significant cervical degenerative disc disease * Prior fusion procedure at any level(s) (C1-T1) * Marked cervical instability on lateral or flexion/extension radiographs * Presence of systemic infection or infection at the surgical site * Diagnosis of a condition, or requires postoperative medication(s), which may interfere with bony/soft tissue healing * History of alcohol and/or drug abuse * Any known allergy to a metal alloy or polyethylene * Morbid obesity * Any significant general illness (e.g., metastatic cancer, HIV)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Overall Success | 24 months | Subject must show 15 point improvement in the Neck Disability Index from baseline to 24 months post operative as well as have no device related SAE, Secondary Surgical Interventions at the index level or any new permanent neurological deterioration. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Neurological Component of Success | 24 months | no new clinically significant permanent abnormalities in neurological function |
| Subsequent Secondary Surgery Component of Success | 24 months | no subsequent secondary surgical intervention at the index level |
| Device-Related SAE Component of Success | 24 months | no device related serious adverse events |
| NDI - Change From Baseline | 24 months | Change from baseline of the Neck Disability Index. NDI has a minimum score of 0 (no disability) and a maximum score of 50 (complete disability) , which is calculated based on the 6 answers to each of the 10 questions. Each answer within a question is given a numerical value 0 to 5. |
| Neck Pain VAS Scores - Change From Baseline | 24 months | Change from baseline of the Neck Pain VAS Scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their neck. |
| Maximum Arm Pain VAS - Change From Baseline | 24 months | Change from baseline in maximum value of the left and right arm VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their arm. |
| Average Arm Pain VAS - Change From Baseline | 24 months | Change from baseline in average of the left and right arm VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their arm. |
| Maximum Shoulder Pain VAS - Change From Baseline | 24 months | Change from baseline in Maximum value of the left and right shoulder VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their shoulder. |
| Average Shoulder Pain VAS - Change From Baseline | 24 months | Change from baseline in Average of the left and right shoulder VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their shoulder. |
| NDI Success | 24 months | 15 point improvement in NDI. NDI has a max score of 50, which is calculated based on the 6 answers to each of the 10 questions. Each answer within a question is given a numerical value 0 to 5. |
| SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 24 months | Change from baseline in Quality of Life - Physical Composite Scores. SF-36 is based on units on a scale; where 0 is severe disability and 100 is no disability. The scores are scaled (based on weighted sum of the questions) |
| Return to Work | 24 months | Estimated Proportion of Subjects Returning to Work |
| SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 24 months | Change from baseline in Quality of Life - Mental Composite Scores. SF-36 is based on units on a scale; where 0 is severe disability and 100 is no disability. The scores are scaled (based on weighted sum of the questions) |
| Work Status Assessment | 24 months | — |
| Activity | 24 months | Clinical Assessment of Activity |
| Subject Satisfaction | 24 months | Subject Satisfaction (Would you have this procedure again?) |
| Global Cervical Range of Motion - Change From Baseline | 24 months | — |
| Average Radiographic Disc Height (mm) - Change From Post-op | 24 months | — |
| Dysphagia Disability Index - Change From Baseline | 24 months | Change from baseline in Dysphagia Disability Index (DDI). The DDI is designed to evaluate dysphagia, difficulty in swallowing, using a 25-item questionnaire. Responses from the questionnaire were scored as always 4, sometimes 2, or never 0, and summed to provide a total score (range 0-100). Higher DDI scores suggest greater subjective signs of dysphagia. |
Countries
Australia, Netherlands, United States
Participant flow
Recruitment details
First subject was enrolled on July 10, 2006. The final study subjects were enrolled on March 22, 2011 and all study sites were informed that enrollment was closed effective March 31, 2011.
Participants by arm
| Arm | Count |
|---|---|
| 1-level Cervical TDR Cervical Total Disc Replacement (Cervical TDR) arthroplasty with the DISCOVER™ Artificial Cervical Disc at a single level of the cervical spine, C3 to C7 inclusive. Cervical TDR: Cervical total disc replacement using a DISCOVER Artificial Cervical Disc. | 185 |
| 1-level ACDF With Plate Anterior Cervical Discectomy and Fusion with plate (ACDF with plate) using allograft spacer and the SLIM-LOC™ Anterior Cervical Plate System at a single level of the cervical spine, C3 to C7 inclusive. ACDF with plate: Anterior cervical discectomy followed by insertion of allograft spacer and placement of an anterior plate. | 167 |
| 2-level Cervical TDR Cervical Total Disc Replacement (Cervical TDR) arthroplasty with the DISCOVER™ Artificial Cervical Disc at two adjacent levels of the cervical spine, C3 to C7 inclusive. Cervical TDR: Cervical total disc replacement using a DISCOVER Artificial Cervical Disc. | 39 |
| 2-level ACDF Anterior Cervical Discectomy and Fusion with plate (ACDF with plate) using allograft spacer and the SLIM-LOC™ Anterior Cervical Plate System at two adjacent levels of the cervical spine, C3 to C7 inclusive. ACDF with plate: Anterior cervical discectomy followed by insertion of allograft spacer and placement of an anterior plate. | 20 |
| Training: 1 & 2-level Cervical TDR Cervical Total Disc Replacement (Cervical TDR) arthroplasty with the DISCOVER™ Artificial Cervical Disc at a single or multiple levels of the cervical spine, C3 to C7 inclusive. Training cohort. Cervical TDR: Cervical total disc replacement using a DISCOVER Artificial Cervical Disc. | 89 |
| Total | 500 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 |
|---|---|---|---|---|---|---|
| Overall Study | Death | 0 | 1 | 0 | 0 | 0 |
| Overall Study | Failure | 9 | 5 | 3 | 2 | 3 |
| Overall Study | Missing NDI and/or neuro. assessment | 13 | 24 | 1 | 3 | 7 |
Baseline characteristics
| Characteristic | 1-level Cervical TDR | 1-level ACDF With Plate | 2-level Cervical TDR | 2-level ACDF | Training: 1 & 2-level Cervical TDR | Total |
|---|---|---|---|---|---|---|
| Age, Continuous | 44.2 years STANDARD_DEVIATION 8.63 | 42.8 years STANDARD_DEVIATION 7.63 | 44.1 years STANDARD_DEVIATION 7.94 | 44.4 years STANDARD_DEVIATION 7.74 | 42.3 years STANDARD_DEVIATION 7.49 | 43.4 years STANDARD_DEVIATION 8 |
| BMI | 28.3 kg/m^2 STANDARD_DEVIATION 4.97 | 27.6 kg/m^2 STANDARD_DEVIATION 4.83 | 28.3 kg/m^2 STANDARD_DEVIATION 4.97 | 30.0 kg/m^2 STANDARD_DEVIATION 3.61 | 28.9 kg/m^2 STANDARD_DEVIATION 5.12 | 28.3 kg/m^2 STANDARD_DEVIATION 4.9 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 7 Participants | 4 Participants | 1 Participants | 1 Participants | 1 Participants | 14 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 172 Participants | 153 Participants | 38 Participants | 19 Participants | 88 Participants | 470 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 6 Participants | 10 Participants | 0 Participants | 0 Participants | 0 Participants | 16 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 2 Participants | 1 Participants | 0 Participants | 1 Participants | 5 Participants |
| Race (NIH/OMB) Black or African American | 8 Participants | 6 Participants | 1 Participants | 2 Participants | 4 Participants | 21 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 6 Participants | 11 Participants | 1 Participants | 0 Participants | 0 Participants | 18 Participants |
| Race (NIH/OMB) White | 170 Participants | 147 Participants | 36 Participants | 18 Participants | 82 Participants | 453 Participants |
| Sex: Female, Male Female | 93 Participants | 89 Participants | 26 Participants | 10 Participants | 42 Participants | 260 Participants |
| Sex: Female, Male Male | 92 Participants | 78 Participants | 13 Participants | 10 Participants | 47 Participants | 240 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk |
|---|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 158 / 186 | 135 / 166 | 38 / 39 | 20 / 20 | 83 / 89 |
| serious Total, serious adverse events | 59 / 186 | 44 / 166 | 14 / 39 | 5 / 20 | 24 / 89 |
Outcome results
Primary
Overall Success
Subject must show 15 point improvement in the Neck Disability Index from baseline to 24 months post operative as well as have no device related SAE, Secondary Surgical Interventions at the index level or any new permanent neurological deterioration.
Time frame: 24 months
Population: The primary outcome was analyzed with an Intent to Treat (As Randomized) analysis. The difference between the number of treated patients and the number of participants analyzed for each group at the 24 month visit is due to: death of one randomized ACDF patient and patients with no data for NDI and Neurological function (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | Overall Success | 137 participants who are successes |
| 1-level ACDF With Plate | Overall Success | 110 participants who are successes |
| 2-level Cervical TDR | Overall Success | 28 participants who are successes |
| 2-level ACDF | Overall Success | 13 participants who are successes |
| Training: 1 & 2-level Cervical TDR | Overall Success | 65 participants who are successes |
Secondary
Activity
Clinical Assessment of Activity
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1-level Cervical TDR | Activity | Moderate | 79 participants |
| 1-level Cervical TDR | Activity | Light | 39 participants |
| 1-level Cervical TDR | Activity | Vigorous | 44 participants |
| 1-level ACDF With Plate | Activity | Light | 30 participants |
| 1-level ACDF With Plate | Activity | Vigorous | 41 participants |
| 1-level ACDF With Plate | Activity | Moderate | 58 participants |
| 2-level Cervical TDR | Activity | Light | 11 participants |
| 2-level Cervical TDR | Activity | Moderate | 17 participants |
| 2-level Cervical TDR | Activity | Vigorous | 7 participants |
| 2-level ACDF | Activity | Vigorous | 2 participants |
| 2-level ACDF | Activity | Light | 5 participants |
| 2-level ACDF | Activity | Moderate | 8 participants |
| Training: 1 & 2-level Cervical TDR | Activity | Moderate | 37 participants |
| Training: 1 & 2-level Cervical TDR | Activity | Light | 21 participants |
| Training: 1 & 2-level Cervical TDR | Activity | Vigorous | 22 participants |
Secondary
Average Arm Pain VAS - Change From Baseline
Change from baseline in average of the left and right arm VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their arm.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Average Arm Pain VAS - Change From Baseline | -32.1 Units on a scale | Standard Deviation 25.62 |
| 1-level ACDF With Plate | Average Arm Pain VAS - Change From Baseline | -28.8 Units on a scale | Standard Deviation 20.88 |
| 2-level Cervical TDR | Average Arm Pain VAS - Change From Baseline | -30.5 Units on a scale | Standard Deviation 25.9 |
| 2-level ACDF | Average Arm Pain VAS - Change From Baseline | -20.6 Units on a scale | Standard Deviation 26.33 |
| Training: 1 & 2-level Cervical TDR | Average Arm Pain VAS - Change From Baseline | -26.6 Units on a scale | Standard Deviation 24.7 |
Secondary
Average Radiographic Disc Height (mm) - Change From Post-op
Time frame: 24 months
Population: As Treated. The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Average Radiographic Disc Height (mm) - Change From Post-op | -1.0 mm | Standard Deviation 0.76 |
| 1-level ACDF With Plate | Average Radiographic Disc Height (mm) - Change From Post-op | -1.0 mm | Standard Deviation 0.83 |
Secondary
Average Shoulder Pain VAS - Change From Baseline
Change from baseline in Average of the left and right shoulder VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their shoulder.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Average Shoulder Pain VAS - Change From Baseline | -34.1 Units on a scale | Standard Deviation 26.45 |
| 1-level ACDF With Plate | Average Shoulder Pain VAS - Change From Baseline | -31.6 Units on a scale | Standard Deviation 22.69 |
| 2-level Cervical TDR | Average Shoulder Pain VAS - Change From Baseline | -31.7 Units on a scale | Standard Deviation 30.36 |
| 2-level ACDF | Average Shoulder Pain VAS - Change From Baseline | -15.6 Units on a scale | Standard Deviation 24.85 |
| Training: 1 & 2-level Cervical TDR | Average Shoulder Pain VAS - Change From Baseline | -31.0 Units on a scale | Standard Deviation 29.12 |
Secondary
Device-Related SAE Component of Success
no device related serious adverse events
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | Device-Related SAE Component of Success | 184 participants who are successes |
| 1-level ACDF With Plate | Device-Related SAE Component of Success | 167 participants who are successes |
| 2-level Cervical TDR | Device-Related SAE Component of Success | 39 participants who are successes |
| 2-level ACDF | Device-Related SAE Component of Success | 20 participants who are successes |
| Training: 1 & 2-level Cervical TDR | Device-Related SAE Component of Success | 89 participants who are successes |
Secondary
Dysphagia Disability Index - Change From Baseline
Change from baseline in Dysphagia Disability Index (DDI). The DDI is designed to evaluate dysphagia, difficulty in swallowing, using a 25-item questionnaire. Responses from the questionnaire were scored as always 4, sometimes 2, or never 0, and summed to provide a total score (range 0-100). Higher DDI scores suggest greater subjective signs of dysphagia.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Dysphagia Disability Index - Change From Baseline | -1.3 Units on a scale | Standard Deviation 7.91 |
| 1-level ACDF With Plate | Dysphagia Disability Index - Change From Baseline | 0.7 Units on a scale | Standard Deviation 7.22 |
| 2-level Cervical TDR | Dysphagia Disability Index - Change From Baseline | 0.3 Units on a scale | Standard Deviation 10.19 |
| 2-level ACDF | Dysphagia Disability Index - Change From Baseline | 1.2 Units on a scale | Standard Deviation 5.89 |
| Training: 1 & 2-level Cervical TDR | Dysphagia Disability Index - Change From Baseline | -0.8 Units on a scale | Standard Deviation 9.56 |
Secondary
Global Cervical Range of Motion - Change From Baseline
Time frame: 24 months
Population: As Treated. The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Global Cervical Range of Motion - Change From Baseline | 5.4 degrees | Standard Deviation 16.14 |
| 1-level ACDF With Plate | Global Cervical Range of Motion - Change From Baseline | -2.8 degrees | Standard Deviation 14.67 |
| 2-level Cervical TDR | Global Cervical Range of Motion - Change From Baseline | 3.0 degrees | Standard Deviation 14.88 |
| 2-level ACDF | Global Cervical Range of Motion - Change From Baseline | -14.4 degrees | Standard Deviation 13.21 |
| Training: 1 & 2-level Cervical TDR | Global Cervical Range of Motion - Change From Baseline | 2.1 degrees | Standard Deviation 15.36 |
Secondary
Maximum Arm Pain VAS - Change From Baseline
Change from baseline in maximum value of the left and right arm VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their arm.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Maximum Arm Pain VAS - Change From Baseline | -52.0 Units on a scale | Standard Deviation 32.69 |
| 1-level ACDF With Plate | Maximum Arm Pain VAS - Change From Baseline | -49.5 Units on a scale | Standard Deviation 33.45 |
| 2-level Cervical TDR | Maximum Arm Pain VAS - Change From Baseline | -42.4 Units on a scale | Standard Deviation 37.54 |
| 2-level ACDF | Maximum Arm Pain VAS - Change From Baseline | -30.9 Units on a scale | Standard Deviation 44.62 |
| Training: 1 & 2-level Cervical TDR | Maximum Arm Pain VAS - Change From Baseline | -44.3 Units on a scale | Standard Deviation 35.61 |
Secondary
Maximum Shoulder Pain VAS - Change From Baseline
Change from baseline in Maximum value of the left and right shoulder VAS scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their shoulder.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Maximum Shoulder Pain VAS - Change From Baseline | -52.1 Units on a scale | Standard Deviation 31.96 |
| 1-level ACDF With Plate | Maximum Shoulder Pain VAS - Change From Baseline | -47.9 Units on a scale | Standard Deviation 30.18 |
| 2-level Cervical TDR | Maximum Shoulder Pain VAS - Change From Baseline | -43.0 Units on a scale | Standard Deviation 34.74 |
| 2-level ACDF | Maximum Shoulder Pain VAS - Change From Baseline | -21.4 Units on a scale | Standard Deviation 43.84 |
| Training: 1 & 2-level Cervical TDR | Maximum Shoulder Pain VAS - Change From Baseline | -45.9 Units on a scale | Standard Deviation 38.13 |
Secondary
NDI - Change From Baseline
Change from baseline of the Neck Disability Index. NDI has a minimum score of 0 (no disability) and a maximum score of 50 (complete disability) , which is calculated based on the 6 answers to each of the 10 questions. Each answer within a question is given a numerical value 0 to 5.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | NDI - Change From Baseline | -33.4 NDI Score | Standard Deviation 17.97 |
| 1-level ACDF With Plate | NDI - Change From Baseline | -33.2 NDI Score | Standard Deviation 18.04 |
| 2-level Cervical TDR | NDI - Change From Baseline | -32.8 NDI Score | Standard Deviation 20.62 |
| 2-level ACDF | NDI - Change From Baseline | -32.9 NDI Score | Standard Deviation 22.1 |
| Training: 1 & 2-level Cervical TDR | NDI - Change From Baseline | -34.3 NDI Score | Standard Deviation 21 |
Secondary
NDI Success
15 point improvement in NDI. NDI has a max score of 50, which is calculated based on the 6 answers to each of the 10 questions. Each answer within a question is given a numerical value 0 to 5.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | NDI Success | 139 participants who are successes |
| 1-level ACDF With Plate | NDI Success | 111 participants who are successes |
| 2-level Cervical TDR | NDI Success | 29 participants who are successes |
| 2-level ACDF | NDI Success | 13 participants who are successes |
| Training: 1 & 2-level Cervical TDR | NDI Success | 67 participants who are successes |
Secondary
Neck Pain VAS Scores - Change From Baseline
Change from baseline of the Neck Pain VAS Scores. VAS is a 100-mm visual analog scale used to assess pain. It asks the subject to place a vertical mark on a 100-mm horizontal line, with 'No pain' listed on the left (at 0 mm) and 'Very severe pain' labeled on the right (at 100 mm). The subject is instructed to indicate the amount of pain they feel in their neck.
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | Neck Pain VAS Scores - Change From Baseline | -47.0 Units on a scale | Standard Error 30.43 |
| 1-level ACDF With Plate | Neck Pain VAS Scores - Change From Baseline | -41.5 Units on a scale | Standard Error 30.57 |
| 2-level Cervical TDR | Neck Pain VAS Scores - Change From Baseline | -36.1 Units on a scale | Standard Error 33.15 |
| 2-level ACDF | Neck Pain VAS Scores - Change From Baseline | -27.2 Units on a scale | Standard Error 26.14 |
| Training: 1 & 2-level Cervical TDR | Neck Pain VAS Scores - Change From Baseline | -46.3 Units on a scale | Standard Error 33.6 |
Secondary
Neurological Component of Success
no new clinically significant permanent abnormalities in neurological function
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | Neurological Component of Success | 161 participants who are successes |
| 1-level ACDF With Plate | Neurological Component of Success | 127 participants who are successes |
| 2-level Cervical TDR | Neurological Component of Success | 35 participants who are successes |
| 2-level ACDF | Neurological Component of Success | 15 participants who are successes |
| Training: 1 & 2-level Cervical TDR | Neurological Component of Success | 77 participants who are successes |
Secondary
Return to Work
Estimated Proportion of Subjects Returning to Work
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | Return to Work | 87 % of subjects who returned to work |
| 1-level ACDF With Plate | Return to Work | 86 % of subjects who returned to work |
| 2-level Cervical TDR | Return to Work | 84 % of subjects who returned to work |
| 2-level ACDF | Return to Work | 90 % of subjects who returned to work |
| Training: 1 & 2-level Cervical TDR | Return to Work | 92 % of subjects who returned to work |
Secondary
SF-36 - Mental Composite Scores (MCS) - Change From Baseline
Change from baseline in Quality of Life - Mental Composite Scores. SF-36 is based on units on a scale; where 0 is severe disability and 100 is no disability. The scores are scaled (based on weighted sum of the questions)
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 9.2 Units on a scale | Standard Deviation 11.66 |
| 1-level ACDF With Plate | SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 8.8 Units on a scale | Standard Deviation 12.01 |
| 2-level Cervical TDR | SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 6.3 Units on a scale | Standard Deviation 12.89 |
| 2-level ACDF | SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 12.2 Units on a scale | Standard Deviation 13.65 |
| Training: 1 & 2-level Cervical TDR | SF-36 - Mental Composite Scores (MCS) - Change From Baseline | 6.3 Units on a scale | Standard Deviation 13.19 |
Secondary
SF-36 - Physical Composite Scores (PCS) - Change From Baseline
Change from baseline in Quality of Life - Physical Composite Scores. SF-36 is based on units on a scale; where 0 is severe disability and 100 is no disability. The scores are scaled (based on weighted sum of the questions)
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-level Cervical TDR | SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 14.2 Units on a scale | Standard Deviation 10.66 |
| 1-level ACDF With Plate | SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 13.3 Units on a scale | Standard Deviation 10.5 |
| 2-level Cervical TDR | SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 15.2 Units on a scale | Standard Deviation 9.23 |
| 2-level ACDF | SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 6.6 Units on a scale | Standard Deviation 10.18 |
| Training: 1 & 2-level Cervical TDR | SF-36 - Physical Composite Scores (PCS) - Change From Baseline | 15.2 Units on a scale | Standard Deviation 10.73 |
Secondary
Subject Satisfaction
Subject Satisfaction (Would you have this procedure again?)
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1-level Cervical TDR | Subject Satisfaction | Definitely Yes | 121 participants |
| 1-level Cervical TDR | Subject Satisfaction | Unsure or Too Early to Tell | 10 participants |
| 1-level Cervical TDR | Subject Satisfaction | Probably Yes | 25 participants |
| 1-level Cervical TDR | Subject Satisfaction | Probably Not | 4 participants |
| 1-level Cervical TDR | Subject Satisfaction | Definitely Not | 1 participants |
| 1-level ACDF With Plate | Subject Satisfaction | Definitely Yes | 86 participants |
| 1-level ACDF With Plate | Subject Satisfaction | Definitely Not | 2 participants |
| 1-level ACDF With Plate | Subject Satisfaction | Unsure or Too Early to Tell | 6 participants |
| 1-level ACDF With Plate | Subject Satisfaction | Probably Yes | 32 participants |
| 1-level ACDF With Plate | Subject Satisfaction | Probably Not | 3 participants |
| 2-level Cervical TDR | Subject Satisfaction | Definitely Yes | 24 participants |
| 2-level Cervical TDR | Subject Satisfaction | Definitely Not | 2 participants |
| 2-level Cervical TDR | Subject Satisfaction | Probably Not | 3 participants |
| 2-level Cervical TDR | Subject Satisfaction | Unsure or Too Early to Tell | 3 participants |
| 2-level Cervical TDR | Subject Satisfaction | Probably Yes | 5 participants |
| 2-level ACDF | Subject Satisfaction | Probably Not | 2 participants |
| 2-level ACDF | Subject Satisfaction | Probably Yes | 4 participants |
| 2-level ACDF | Subject Satisfaction | Unsure or Too Early to Tell | 2 participants |
| 2-level ACDF | Subject Satisfaction | Definitely Yes | 8 participants |
| 2-level ACDF | Subject Satisfaction | Definitely Not | 0 participants |
| Training: 1 & 2-level Cervical TDR | Subject Satisfaction | Definitely Not | 0 participants |
| Training: 1 & 2-level Cervical TDR | Subject Satisfaction | Definitely Yes | 62 participants |
| Training: 1 & 2-level Cervical TDR | Subject Satisfaction | Probably Yes | 9 participants |
| Training: 1 & 2-level Cervical TDR | Subject Satisfaction | Unsure or Too Early to Tell | 4 participants |
| Training: 1 & 2-level Cervical TDR | Subject Satisfaction | Probably Not | 3 participants |
Secondary
Subsequent Secondary Surgery Component of Success
no subsequent secondary surgical intervention at the index level
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| 1-level Cervical TDR | Subsequent Secondary Surgery Component of Success | 176 participants who are successes |
| 1-level ACDF With Plate | Subsequent Secondary Surgery Component of Success | 160 participants who are successes |
| 2-level Cervical TDR | Subsequent Secondary Surgery Component of Success | 35 participants who are successes |
| 2-level ACDF | Subsequent Secondary Surgery Component of Success | 18 participants who are successes |
| Training: 1 & 2-level Cervical TDR | Subsequent Secondary Surgery Component of Success | 84 participants who are successes |
Secondary
Work Status Assessment
Time frame: 24 months
Population: Intent to Treat (As Randomized). The difference between the number of treated patients and the number of participants analyzed is due to: death of one randomized ACDF patient, patients who experienced a Device Failure before the 24 month visit, and patients with no data collected for this secondary outcome (missing data).
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1-level Cervical TDR | Work Status Assessment | Not Working | 28 participants |
| 1-level Cervical TDR | Work Status Assessment | Full Time | 111 participants |
| 1-level Cervical TDR | Work Status Assessment | Part Time | 12 participants |
| 1-level Cervical TDR | Work Status Assessment | Full or Part Time | 123 participants |
| 1-level Cervical TDR | Work Status Assessment | Total | 151 participants |
| 1-level Cervical TDR | Work Status Assessment | Not Applicable | 16 participants |
| 1-level ACDF With Plate | Work Status Assessment | Total | 119 participants |
| 1-level ACDF With Plate | Work Status Assessment | Not Applicable | 12 participants |
| 1-level ACDF With Plate | Work Status Assessment | Not Working | 18 participants |
| 1-level ACDF With Plate | Work Status Assessment | Part Time | 10 participants |
| 1-level ACDF With Plate | Work Status Assessment | Full or Part Time | 101 participants |
| 1-level ACDF With Plate | Work Status Assessment | Full Time | 91 participants |
| 2-level Cervical TDR | Work Status Assessment | Full or Part Time | 23 participants |
| 2-level Cervical TDR | Work Status Assessment | Total | 29 participants |
| 2-level Cervical TDR | Work Status Assessment | Not Working | 6 participants |
| 2-level Cervical TDR | Work Status Assessment | Part Time | 2 participants |
| 2-level Cervical TDR | Work Status Assessment | Full Time | 21 participants |
| 2-level Cervical TDR | Work Status Assessment | Not Applicable | 9 participants |
| 2-level ACDF | Work Status Assessment | Full or Part Time | 14 participants |
| 2-level ACDF | Work Status Assessment | Full Time | 12 participants |
| 2-level ACDF | Work Status Assessment | Part Time | 2 participants |
| 2-level ACDF | Work Status Assessment | Not Applicable | 0 participants |
| 2-level ACDF | Work Status Assessment | Total | 16 participants |
| 2-level ACDF | Work Status Assessment | Not Working | 2 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Total | 79 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Part Time | 7 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Full Time | 61 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Not Applicable | 4 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Full or Part Time | 68 participants |
| Training: 1 & 2-level Cervical TDR | Work Status Assessment | Not Working | 11 participants |