Triadyme-C, a Polycrystalline Diamond Compact Cervical Disc Replacement (cTDR)

Study Overview
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Brief Summary
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This Post Market Clinical Follow-up (PMCF) is conducted to collect clinical and radiographic outcome information on patients suffering from intractable symptomatic cervical disc disease requiring 1- or 2-level reconstruction of the disc from C3-C7, after being treated with the Triadyme-C polycrystalline diamond compact cervical disc replacement.

Detailed Description
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Approximately fifty percent of the population has evidence of degenerative changes in their cervical spine by the age of fifty. As part of the aging process, the intervertebral discs wear out. They lose their flexibility and elasticity and begin to collapse or even herniate. This process may result in a pathological condition called cervical Degenerative Disc Diseases (cDDD). cDDD can either be asymptomatic or symptomatic, showing different symptoms such as neck, shoulder, head, arm or leg pain, possibly associated with numbness, tingling or weakness in the upper extremity. In most cases symptomatic cDDD is initially treated conservatively with rest, immobilization, physical therapy, chiropractic manipulation and pain medication. For those cases not responding to conservative therapy, anterior cervical discectomy and fusion (ACDF) is a standard technique. The primary purpose of ACDF is to excise any disc material (discectomy), which compresses the spinal nerve or cord causing pain, sensory disturbance or weakness at the affected level, followed by interbody fusion of the adjacent vertebrae using grafts or intersomatic devices to compensate the instability and the loss of disc height resulting from discectomy. Despite the success of this common procedure, some disadvantages are to be mentioned including donor site morbidity when autografts are used, graft or device subsidence or pseudarthrosis of the segment to be fused. Besides this, physiological motion of successfully fused segments is no longer possible. This alters the loading and kinematics of adjacent spine segments which is believed by some authors to lead to adjacent segment overload as reported by several clinical and biomechanical studies. To address the disadvantages of ACDF, cervical total disc replacement (cTDR) has been developed in the 1990s, with the aim to carry the load and restore the normal disc height while preserving almost physiological segmental motion. Today, several different cTRD designs are on the market, some of them with mid- to long-term results. A number of randomized controlled trials indicate clinical equivalence or even superiority of cTDR in some aspects compared to ACDF. The Dymicron Triadyme-C cTDR is a two-piece articulating artificial disc prosthesis. Its patented tri-lobe articulation mechanism consists of three spherical lobes mating to three non-congruent, spherical pockets. The motion of these three lobes within their associated pockets emulates and controls natural motion of the cervical spine motion segment in all degrees of freedom.Triadyme-C is a self-centering device. This is achieved by the implant growing in height as it moves away from its center. The further away from center, the tighter the ligaments will be stretched. Each half of the Triadyme-C is a sintered monobloc, consisting of a polycrystalline diamond (PCD) bearing surface with a base of titanium-titanium carbide (Ti-TiC) composite. PCD is a sintered material composed of fused diamond crystals (typically more than 90%) and a small amount of catalyst sintering metal. The polycrystalline structure of diamond, together with the small amount of residual metal alloy, contributes significantly to the extraordinary toughness and abrasion-resistance of the material. PCD retains many of the phenomenal properties of natural diamond, including hardness, but in an isotropic form that is far more resistant to fracture. This Post Market Clinical Follow-up (PMCF) is conducted to collect clinical and radiographic outcome information on patients suffering from intractable symptomatic cervical disc disease requiring 1- or 2-level reconstruction of the disc from C3-C7, after being treated with the Triadyme-C polycrystalline diamond compact cervical disc replacement.

Official Title
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Triadyme-C, a Polycrystalline Diamond Compact Cervical Disc Replacement (cTDR): Evaluation of Clinical and Radiographic Outcome

Conditions
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Intervertebral Disc Disorder Cervical

Intervention / Treatment
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* Device: cTDR


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1- or 2-level cTDR surgery between C3 and C7 Age ≥ 18 years Skeletally mature patient Patient suffers from intractable symptomatic cervical disc disease (SCDD) with neck or arm (radicular) pain and/or a functional/neurological deficit At least one of the following conditions must be present and confirmed by radiographic (CT, MRI, x-ray, etc.) studies: herniated nucleus pulposus, spondylosis (indicated by the presence of osteophytes), or loss of disc height. At least six weeks of non-operative treatment for SCDD has been tried and failed prior to implantation Psychosocially, mentally, and physically able to fully comply with the clinical protocol and willing to adhere to follow-up schedule and requirements. Patient signed Informed Consent Exclusion Criteria: Active systemic infection or infection localized to the site of implantation Allergy or sensitivity to the implant materials Osteoporosis, defined as a Dual-energy X-ray Absorptiometry (DXA) bone mineral density T-score equal to or less than -2.5 Marked cervical instability on radiographs (e.g., radiographic signs of subluxation greater than 3.5 mm or angulation of the disc space more than 11 degrees greater than adjacent segments) Severe spondylosis characterized by bridging osteophytes or an absence of motion (less than 2 degrees) Significant cervical anatomical deformity or compromised vertebral bodies at the index level (e.g. ankylosing spondylitis, rheumatoid arthritis, or compromise due to current or past trauma) Significant kyphotic deformity or significant reversal of lordosis Previous cervical spinal surgery, other than discectomy at the levels to be operated on Use of any spinal implant other than Triadyme-C Adiposity, severe obesity (BMI > 40 kg/m2) Patient who takes immunosuppressive or long-term steroid use Fever Systemic or metabolic illnesses (i.e. disease of bone-metabolism, insulin-dependent diabetes ...) Patient who is suffering from rheumatoid or other inflammatory joint disease Patient with any known active malignancy within the last 2 years Any medical or surgical condition that could preclude the potential success of the implantation Psychosocial issues; lack of co-operation by the patient, drug abuse or alcoholism Unwillingness or inability of the patient to follow the instructions for postoperative treatment or with the follow-up evaluation schedule Female patient who is pregnant or plans to become pregnant during the course of the study Prisoner

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1- or 2-level cTDR<br>patients suffering from intractable symptomatic cervical disc disease (SCDD) requiring 1- or 2-level reconstruction of the disc from C3-C7 | Device: cTDR<br>* The surgical procedure for the Triadyme-C total disc replacement corresponds to the standard surgical technique for cTDR: Implantation through a standard anterior cervical approach Midline identification Routine discectomy with endplate preparation and decompression Implant sizing and trial implantation Keel preparation Implant preparation and loading of the appropriate Triadyme-C implant Triadyme-C insertion, positioned as close to the midline as possible<br>* Other names: cervical Total Disc Replacement;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neck Disability Index (NDI) | Clinical outcome is measured by the Neck Disability Index (NDI) as published by Vernon et. al.. The primary endpoint of the study will be the mean total NDI at the 2 year postoperative assessment. | 2 years postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analogue Scale (VAS) on neck pain | The Visual Analogue Scale (VAS) represents the subject's intensity of neck pain during the last week measured on a line of 10 cm length, stretching from 'no pain (0 cm) to 'pain as bad as it could be' (10 cm). | 2 years postoperative | 
| Visual Analogue Scale (VAS) on arm pain | The VAS represents the subject's intensity of pain experienced in the pain-dominant arm during the last week measured on a line of 10 cm length, stretching from 'no pain (0 cm) to 'pain as bad as it could be' (10 cm). | 2 years postoperative | 
| Rate of device failure | Failure rate is based on the number of subjects whose radiographs, MRIs and/or CTs showed one or more device failures during the 2 year follow-up period after implantation divided by the total number of patients with 2 year radiographs or earlier failures. | 2 years postoperative | 
| Rate of subsequent surgical interventions | The following subsequent surgical intervention rates at index level are secondary study endpoints removal revision reoperation supplemental fixation Each subsequent surgical intervention rate is based on the number of subjects who showed one or more surgical interventions at index level per category during the 2 year follow-up period after implantation divided by the total number of patients with 2 year results or earlier subsequent surgical interventions. | 2 years postoperative | 
| Range of motion at index level | Range of motion (ROM) at index level means the degree of flexion/extension motion in the replaced segment. It is measured along the endplates according to the technique of Cobb in degrees in the sagittal plane on active lateral flexion and extension radiographs. ROM is defined as the difference of endplate alignment (Cobb angle) in maximum active flexion and maximum active extension per follow-up examination. | 2 years postoperative | 
| Rate of subsequent surgical interventions at symptomatic adjacent levels | The rate of subsequent surgical interventions at symptomatic adjacent levels is based on the number of subjects who underwent subsequent surgery to treat progressive adjacent segment disease during the 2 year follow-up period after implantation divided by the total number of patients with 2 year results or earlier adjacent subsequent surgical interventions. | 2 years postoperative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cervical total disc replacement (cTDR)