Investigation of the Two Level Simplify® Cervical Artificial Disc

December 16, 2025 updated by: NuVasive

Clinical Study Protocol for the Investigation Of The Two Level Simplify® Cervical Artificial Disc

This study is intended to demonstrate that the Simplify® Cervical Artificial Disc (Simplify® Disc) is at least as safe and effective as conventional anterior cervical discectomy and fusion (ACDF) when used to treat two contiguous discs from C3 to C7 following discectomy at two contiguous levels for intractable radiculopathy (arm pain and/or a neurological deficit) with neck pain or myelopathy due to abnormalities localized to the levels of the two contiguous disc spaces in subjects who are unresponsive to conservative management.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The objective of this clinical study is to evaluate the safety and effectiveness of the two-level Simplify® Disc compared to conventional two-level ACDF in skeletally mature patients for reconstruction of two contiguous discs from C3 to C7 following discectomy at two contiguous levels for intractable radiculopathy (arm pain and/or a neurological deficit) with neck pain or myelopathy due to abnormalities localized to the levels of the two contiguous disc spaces that are unresponsive to conservative management.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
182

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Orange, California, United States, 92868
        • Orthopaedic Education and Research Institute of Southern California
      • Santa Monica, California, United States, 90403
        • The Spine Institute for Spine Restoration
    • Colorado
      • Thornton, Colorado, United States, 80229
        • Spine Education and Research Foundation
    • Connecticut
      • Hamden, Connecticut, United States, 06518
        • Connecticut Orthopaedic Specialists
    • Florida
      • Sarasota, Florida, United States, 34232
        • Kennedy-White orthopedic Center
    • Illinois
      • Evanston, Illinois, United States, 60201
        • Northshore University Health System
    • Indiana
      • Carmel, Indiana, United States, 46032
        • Indiana Spine Group
      • Fort Wayne, Indiana, United States, 46845
        • Parkview Research Center
    • Kentucky
      • Paducah, Kentucky, United States, 42003
        • Orthopaedic Institute of Western Kentucky
    • Louisiana
      • Shreveport, Louisiana, United States, 71101
        • Spine Institute of Louisiana
    • Michigan
      • Royal Oak, Michigan, United States, 48073
        • William Beaumont Hospital
    • New York
      • Lockport, New York, United States, 14094
        • Buffalo Spine Surgery
    • North Carolina
      • Charlotte, North Carolina, United States, 28204
        • Carolina Neurosurgery and Spine Associates
    • Oregon
      • Springfield, Oregon, United States, 97477
        • Oregon Neurosurgery
    • Texas
      • Addison, Texas, United States, 75001
        • Texas Spine Consultants
      • Plano, Texas, United States, 75093
        • Texas Back Institute
    • Utah
      • West Jordan, Utah, United States, 84088
        • The Disc Replacement Center
    • Virginia
      • Reston, Virginia, United States, 20191
        • Virginia Spine Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Has cervical degenerative disc disease at two (2) adjacent cervical levels (from C3 C7) requiring surgical treatment and involving intractable radiculopathy, myelopathy, or both;
  • Has a herniated disc and/or osteophyte formation at each level to be treated that is producing symptomatic nerve root and/or spinal cord compression. The condition is documented by patient history (e.g., neck pain with arm pain, functional deficit and/or neurological deficit), and the requirement for surgical treatment is evidenced by radiographic studies (e.g., CT, MRI, x-rays, etc.);
  • Has been unresponsive to non-operative treatment for at least six weeks or has the presence of progressive symptoms or signs of nerve root/spinal cord compression in the face of continued non-operative management;
  • Has no previous surgical intervention at the involved levels or any subsequent planned/staged surgical procedure at the involved or adjacent level(s);
  • Must be at least 18 years of age and be skeletally mature at the time of surgery;
  • Has a preoperative Neck Disability Index (NDI) ≥ 30;
  • Has a preoperative neck pain score > 8 based on the preoperative Neck and Arm Pain Questionnaire;
  • If a female of childbearing potential, patient is non-pregnant, non-nursing, and agrees not to become pregnant during the study period;
  • Is willing to comply with the study plan and sign the Patient Informed Consent Form.

Exclusion Criteria:

  • Has a cervical spinal condition other than symptomatic cervical DDD requiring surgical treatment at the involved levels;

  • Has documented or diagnosed cervical instability relative to adjacent segments at either level, defined by dynamic (flexion/extension) radiographs showing:

    • Sagittal plane translation > 3.5 mm, or
    • Sagittal plane angulation > 20°;
  • Has more than two cervical levels requiring surgical treatment;
  • Has a fused level (or artificial disc replacement) adjacent to the levels to be treated;
  • Has severe pathology of the facet joints of the involved vertebral bodies;
  • Has had previous surgical intervention at either one or both of the involved levels or at adjacent levels;
  • Axial neck pain only (no radicular or myelopathy symptoms);
  • Has been previously diagnosed with osteopenia or osteomalacia;

  • Has any of the following that may be associated with a diagnosis of osteoporosis (if "Yes" to any of the below risk factors, a DEXA Scan will be required to determine eligibility):

    • Postmenopausal non-black female over 60 years of age who weighs less than 140 pounds;
    • Postmenopausal female who has sustained a non-traumatic hip, spine, or wrist fracture;
    • Male over the age of 70;
    • Male over the age of 60 who has sustained a non-traumatic hip or spine fracture.
    • If the level of bone mineral density is a T score of -1.5 or lower (i.e., -1.6, 1.7, etc.), then the patient is excluded from the study
  • Has presence of spinal metastases;
  • Has overt or active bacterial infection, either local or systemic;
  • Has insulin-dependent diabetes;
  • Has chronic or acute renal failure or prior history of renal disease;
  • Known PEEK, ceramic, titanium allergy;
  • Is mentally incompetent (if questionable, obtain psychiatric consult);
  • Is a prisoner;
  • Is pregnant;
  • Is currently an alcohol and/or drug abuser or currently undergoing treatment for alcohol and/or drug abuse;
  • Is involved with current or pending litigation regarding a spinal condition;
  • Has received drugs that may interfere with bone metabolism within two weeks prior to the planned date of spinal surgery (e.g., steroids or methotrexate), excluding routine perioperative anti-inflammatory drugs;
  • Has a history of an endocrine or metabolic disorder known to affect osteogenesis (e.g., Paget's Disease, renal osteodystrophy, Ehlers-Danlos Syndrome, or osteogenesis imperfecta);
  • Has a condition that requires postoperative medications that interfere with the stability of the implant, such as steroids. (This does not include low-dose aspirin for prophylactic anticoagulation and routine perioperative anti-inflammatory drugs);
  • Has received treatment with an investigational therapy within 28 days prior to implantation surgery or such treatment is planned during the 16 weeks following implantation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Simplify Disc
Simplify Disc at two levels of the cervical spine
Device: Simplify Disc
Simplify Disc at two levels of the cervical spine
No Intervention: Historical Control
This study will utilize a non-concurrent historical control with subject-level data on a parallel group design. The historical control group will be formed from the randomized ACDF arm of a previously completed two level cervical disc trial.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Composite Clinical Success (CCS) Rate of the Simplify® Disc
Time Frame: 24 Months

Individual success is defined as at least a 15 point improvement in Neck Disability Index (NDI) Score at 24 months compared with baseline, maintenance or improvement in neurologic status at 24 months compared with baseline, no additional surgical procedure at the index level within 24 months, and the absence of a serious adverse event classified as implant-associated or implant/surgical procedure-associated within 24 months.

NDI scale is reported in a range from 0 - 100, with 0 consistent with best ability to function and 100 with worst ability to function.
24 Months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Neurological Status
Time Frame: Baseline, 24mos
Neurological success was defined as maintenance or improvement in neurologic status at Month 24 as compared to baseline, as determined by the independent Clinical Events Committee (CEC). The CEC reviews neurological exams of motor, sensory, reflex, and myelopathic gait to make an adjudication determination.
Baseline, 24mos
Number of Subjects With 15-point Improvement in NDI at 3 Months (Time to Recovery)
Time Frame: Baseline, 3mos
Time to recovery is defined as time to first 15-point improvement in NDI NDI scale is reported in a range from 0 - 100, with 0 consistent with best ability to function and 100 with worst ability to function.
Baseline, 3mos
Neck Pain Intensity Questionnaire
Time Frame: Baseline, 24mos.
Changes of at least 2 points on a 10-point scale will be regarded as clinically significant (0=no pain; 10=worst pain)
Baseline, 24mos.
Arm Pain Intensity Questionnaire
Time Frame: Baseline, 24mos.
Changes of at least 2 points on a 10-point scale will be regarded as clinically significant (0=no pain; 10=worst pain)
Baseline, 24mos.
Patient Questionnaires- Treatment Satisfaction Survey
Time Frame: Baseline, 24mos.
Question 1 - "I am satisfied with the results of my surgery" was compared between groups at Month 24. Answer options ranged from definitely true to definitely false.
Baseline, 24mos.
SF-36v2 Health Survey Physical Component Score (PCS) Maintenance or Improvement
Time Frame: Baseline, 24mos
The PCS is a sub-score of the SF-36. The SF-36 is a multipurpose survey with 36 questions. The questions were combined, scored, and weighted to create two scores that provide glimpses into mental and physical functioning and overall health-related quality-of-life. Higher scores indicate better outcomes. Scores range from 0-50. Maintenance or improvement was defined as PCS(Postop) - PCS(Preop) ≥0.
Baseline, 24mos
SF-36 Mental Component Score (MCS) Maintenance or Improvement
Time Frame: Baseline, 24mos.
The MCS is a sub-score of the SF-36. The SF-36 is a multipurpose survey with 36 questions. The questions were combined, scored, and weighted to create two scores that provide glimpses into mental and physical functioning and overall health-related quality-of-life. Higher scores indicate better outcomes. Scores range from 0-50. Maintenance or improvement was defined as MCS(Postop) - MCS(Preop) ≥0.
Baseline, 24mos.
Dysphagia Handicap Index (DHI)
Time Frame: Baseline, 24mos.

Dysphagia Handicap Index (DHI scale) for the investigational Simplify® Disc at 24 months compared to baseline. A higher score is indicative of a less desirable outcome. It is scored 0-100.

Data was not collected on DHI in the historical ACDF control group. Only Simplify Disc subjects are reported. This was pre-specified in the study design.
Baseline, 24mos.
Physician's Perception of Results
Time Frame: Baseline, 24mos.
Results at 24 months for the investigational Simplify® Disc and at 24 months for the control ACDF will also be categorized by the physician according to their perception of the results. Available responses include excellent, good, fair, and poor. Maintenance or improvement was defined as either maintenance of the assigned preoperative grade or any shift to a more favorable grade postoperatively (e.g. poor to fair, fair to good).
Baseline, 24mos.
Change in Average Disc Height (Superior Index Level)
Time Frame: Baseline, 24mos.

Average disc height (superior index level) at 24 months was compared to the baseline measurement and the change was calculated. Measurements were scored by an independent core lab. Average disc height is calculated as the simple average of the anterior and posterior disc heights.

Data was not collected on disc height in the historical ACDF control group. Only Simplify Disc subjects are reported. This was pre-specified in the study design.
Baseline, 24mos.
Change in Average Disc Height (Inferior Index Level)
Time Frame: Baseline, 24M

Average disc height (inferior index level) at 24 months was compared to the baseline measurement and the change was calculated. Measurements were scored by an independent core lab. Average disc height is calculated as the simple average of the anterior and posterior disc heights.

Data was not collected on disc height in the historical ACDF control group. Only Simplify Disc subjects are reported. This was pre-specified in the study design.
Baseline, 24M
Superior Adjacent Level Disc Degeneration (ALDD)
Time Frame: Baseline, 24mos.

Outcome reports the number and percentage of subjects with adjacent level disc degeneration (ALDD) above the index level based on X-ray images. Degeneration was graded as none (no degenerative changes), doubtful (Minimal osteophytosis only), minimal (Definite osteophytosis with some sclerosis of anterior part of vertebral plates), moderate (Marked osteophytosis and sclerosis of vertebral plates with slight narrowing of disk space), severe (Large osteophytes, marked sclerosis of vertebral plates, and marked narrowing of disk space), indeterminate, or unable to assess.

Data was not collected on ALDD in the historical ACDF control group. Only Simplify Disc subjects are reported. This was pre-specified in the study design.
Baseline, 24mos.
Inferior Adjacent Level Disc Degeneration (ALDD)
Time Frame: Baseline, 24mos.

Outcome reports the number and percentage of subjects with adjacent level disc degeneration (ALDD) below the index level based on X-ray images. Degeneration was graded as none (no degenerative changes), doubtful (Minimal osteophytosis only), minimal (Definite osteophytosis with some sclerosis of anterior part of vertebral plates), moderate (Marked osteophytosis and sclerosis of vertebral plates with slight narrowing of disk space), severe (Large osteophytes, marked sclerosis of vertebral plates, and marked narrowing of disk space), indeterminate, or unable to assess.

Data was not collected on ALDD in the historical ACDF control group. Only Simplify Disc subjects are reported. This was pre-specified in the study design.
Baseline, 24mos.
Facet Degeneration (Superior Index Level)
Time Frame: Baseline, 24mos.

Facet degeneration was assessed using MRI for the investigational Simplify Disc at 24 months compared to baseline. Degeneration was graded as none (normal facet joint space), mild (narrowing of the facet joint space and / or small osteophytes and / or mild hypertrophy of the articular process), moderate (narrowing of the facet joint space and/or moderate osteophytes and/or moderate hypertrophy of the articular process and / or mild subarticular bone erosions), severe (Narrowing of the facet joint space and/or large osteophytes and/or severe hypertrophy of the articular process and/or severe subarticular bone erosions and/or subchondral cysts), indeterminate, or unable to assess.

Facet degeneration was not assessed in the ACDF historical control group, as there is no 24 month MRI. This was pre-specified in the study design.
Baseline, 24mos.
Facet Degeneration (Inferior Index Level)
Time Frame: Baseline, 24mos.

Facet degeneration was assessed using MRI for the investigational Simplify Disc at 24 months compared to baseline. Degeneration was graded as none (normal facet joint space), mild (narrowing of the facet joint space and / or small osteophytes and / or mild hypertrophy of the articular process), moderate (narrowing of the facet joint space and/or moderate osteophytes and/or moderate hypertrophy of the articular process and / or mild subarticular bone erosions), severe (Narrowing of the facet joint space and/or large osteophytes and/or severe hypertrophy of the articular process and/or severe subarticular bone erosions and/or subchondral cysts), indeterminate, or unable to assess.

Facet degeneration was not assessed in the ACDF historical control group, as there is no 24 month MRI. This was pre-specified in the study design.
Baseline, 24mos.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
NuVasive

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Kyle Malone, NuVasive

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 12, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 24, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 29, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 20, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 21, 2017

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 16, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • G150206

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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