PMCF Study on the Effectiveness and Safety of METROSAN Spinal Systems and BONEGRAFT Filling Materials

This prospective, multi-center, observational study evaluates the safety and clinical performance of Titania® spinal instrumentation and fusion systems (manufactured by METROSAN End. ve Elk. Mek. Cihazlar ve Tibbi Malz. San. Tic. Ltd. Sti.) and Bonegraft® bone filling materials, including synthetic bone grafts and bone cements (manufactured by Bonegraft Biyolojik Malzemeler San. ve Tic. A.S.). All investigational products are CE marked and registered in the Turkish Ministry of Health's Product Tracking System (UTS).

The study is purely observational; no additional medical procedures, interventions, or tests beyond routine clinical practice will be performed. Data collection includes retrospective review of preoperative and intraoperative information from patient files, followed by prospective follow-up data collection using a study-specific Electronic Case Report Form (e-CRF). Subjects will be evaluated during routine clinical visits at post-operative Day 12 (±5 days), Week 6, and Months 3, 6, and 12.

Seventeen distinct product groups are evaluated independently, covering cervical interbody fusion cages (Titanium and PEEK), posterior cervical stabilization systems, cervical plate systems, cervical dynamic stabilization systems, cervical disc prostheses (Titanium and PEEK), lumbar interbody fusion cages (Titanium and PEEK), interspinous fusion devices, posterior thoracolumbar stabilization systems, posterior thoracolumbar clamp systems, thoracolumbar dynamic stabilization systems, and bone filling materials (bone cements and synthetic bone grafts).

The enrollment period is planned for 12 months, followed by a 12-month follow-up for each participant. An additional 5 months is allocated for data analysis and reporting, with a total study duration of 29 months. The total estimated enrollment is 561 subjects.

The study is conducted in accordance with the EU Medical Device Regulation (MDR) 2017/745, the Turkish Medical Device Regulation (dated 02.06.2021), ICH-GCP guidelines, the Declaration of Helsinki, and applicable Turkish legislation regarding the protection of personal data.

• Titania® Cervical Interbody Fusion Cage (Titanium) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Cervical Interbody Fusion Cage (PEEK) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Posterior Cervical Stabilization System (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Cervical Plate System (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Cervical Dynamic Stabilization System (Elastic Rod) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Cervical Disc Prosthesis (Titanium) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Cervical Disc Prosthesis (PEEK) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Lumbar Interbody Fusion Cages (Titanium) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Lumbar Interbody Fusion Cages (PEEK) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Interspinous Fusion Device (Titanium) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Posterior Thoracolumbar Stabilization Systems (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Posterior Thoracolumbar Clamp Systems (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Titania® Thoracolumbar Dynamic Stabilization System (Elastic Rod) (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Bonegraft® Synthetic Bone Grafts (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.
• Bonegraft® Bone Cement (Device): This is a post-market clinical follow-up (PMCF) of the CE-marked device used according to its intended purpose within routine clinical practice. As this is an observational study, the device is selected and applied based on the physician's clinical judgment, and no additional interventions or procedures beyond standard care are performed.

Primary outcomes

• Change in Neck Disability Index (NDI) score from baseline (for Cervical Spinal Instrumentation and Fusion Systems) [[12 months]]: The NDI is used to evaluate neck-pain-related disability. It consists of 10 items, each scored from 0 to 5. While the total raw score ranges from 0 to 50, results are expressed as a percentage (0-100%) for clinical evaluation, consistent with the referenced literature (Heller et al., 2009). Following clinical benchmarks, a reduction of ≥15% in the NDI score at the 12th-month follow-up compared to baseline is defined as a successful clinical improvement.
• Change in Oswestry Disability Index (ODI) score from baseline (for Thoracolumbar Spinal Instrumentation and Fusion Systems) [[12 months]]: The ODI is used to assess the impact of thoracolumbar pain on daily life activities (personal care, lifting, walking, sitting, standing, sleeping, sexual life, social life, and travel). It consists of 10 items, each scored from 0 to 5. The total score is calculated using the formula: (total score x 100) / (5 x number of questions answered), resulting in a scale from 0 (best) to 100 (worst). Evaluations will be performed at baseline (pre-op) and at each follow-up visit (Day 12, Week 6, and Months 3, 6, and 12). A reduction of ≥15 points in the ODI score at the 12th-month follow-up compared to baseline is defined as a successful clinical improvement.
• Fusion rate for Spinal Fusion Systems [[12 months]]: Fusion status will be evaluated using radiographs and/or CT scans (if available) at each postoperative follow-up visit. The assessment is based on the presence of a continuous trabecular bone bridge between the vertebral bodies. Fusion will be categorized into three groups: Solid Fusion: Presence of a continuous bone bridge between the vertebrae. Fibrous Fusion: Absence of a continuous bone bridge, but no signs of instability (translation < 3 mm on dynamic radiographs). Non-fusion: Absence of a continuous bone bridge along with abnormal motion (> 3 mm translation on radiographs). The evaluation will be concluded once solid fusion is achieved.
• Adjacent segment motion in subjects with dynamic instrumentation [[12 months]]: In subjects undergoing dynamic posterior stabilization, motion at the adjacent segments will be evaluated using flexion and extension radiographs (if available) at all follow-up visits. The primary assessment involves measuring the differences in the disc space angles. These measurements will be compared with baseline (preoperative) values to monitor changes in adjacent segment mobility over the 12-month follow-up period.
• Change in Intervertebral Disc Height [[12 months]]: The intervertebral disc height will be evaluated at each follow-up visit using the Dabbs method. The assessment is based on the average of the measurements taken from the anterior and posterior regions of the disc space, expressed in millimeters (mm) by the formula (A+B)/2. These radiological measurements will be compared with preoperative (baseline) values to identify any changes in disc height throughout the 12-month follow-up period.
• Assessment of Intervertebral Disc Degeneration [12 months]: Intervertebral disc degeneration will be evaluated at each follow-up visit using the Pfirrmann Classification system. This system grades the degree of disc degeneration based on MRI (Magnetic Resonance Imaging) findings, focusing on disc structure, distinction between nucleus and annulus, signal intensity, and disc height. The scale ranges from Grade I (normal disc structure with high signal intensity) to Grade V (severe degeneration with collapsed disc space). Categorical grades obtained at each control period will be compared with baseline (preoperative) status to monitor the progression or stabilization of disc degeneration throughout the 12-month follow-up period, where a shift toward higher grades signifies worsening of degeneration.
• Cervical and segmental lordosis assessment (for Cervical Spinal Instrumentation and Fusion Systems) [[12 months]]: Cervical and segmental lordosis will be evaluated at each follow-up visit and compared with preoperative measurements. Lateral radiographs of the cervical spine will be used to measure lordosis angles using the Cobb angle method. This assessment aims to monitor the maintenance or restoration of the sagittal alignment of the cervical spine and the specific treated segments throughout the 12-month follow-up period.
• Lordosis restoration and sagittal balance assessment (for Thoracolumbar Spinal Instrumentation and Fusion Systems) [[12 months]]: Sagittal balance and lordosis restoration will be evaluated using full-spine radiographs (tele-radiographies, if available) at baseline and each follow-up visit (Day 12, Week 6, Months 3, 6, and 12). Clinical success will be assessed based on the Schwab sagittal alignment classification parameters. This assessment is a categorical evaluation based on whether patients achieve the predefined optimal correction thresholds for three key spinal parameters: 1) Sagittal Vertical Axis (SVA) < 50 millimeters, 2) Pelvic Tilt (PT) < 20 degrees, and 3) Pelvic Incidence minus Lumbar Lordosis (PI-LL) mismatch within ±9 degrees. At each follow-up period, patients will be categorized into two groups: those who achieve all these optimal parameters and those who do not. Patients meeting all three thresholds will be classified as 'successful' according to the Schwab criteria.
• Incidence of adverse events and complications [[12 months]]: Safety data will be collected by recording all adverse events (AEs) and complications encountered during the 12-month follow-up period. This includes intraoperative complications, device-related failures, and any postoperative adverse events (e.g., infection, neurological deficit, or reoperation).

Secondary outcomes

• Clinical outcome assessment using Odom's Criteria [[12 months]]: Patient clinical outcomes will be evaluated at each follow-up visit using Odom's Criteria, which classifies results as 'Excellent', 'Good', 'Fair', or 'Poor' based on symptom relief and the ability to perform daily activities. Clinical success is defined as the proportion of subjects achieving 'Excellent' or 'Good' scores, representing significant improvement compared to baseline.
• Assessment of pain using Visual Analog Scale (VAS) [[12 months]]: Pain intensity and changes in pain levels will be evaluated at each follow-up visit using the Visual Analog Scale (VAS) and compared with baseline measurements. Patients mark their pain level on a 100 mm (or 10 cm) line, where 0 represents no pain and 100 represents the worst pain. A decrease of ≥20 mm (or 2 cm) in pain intensity at the 12th-month follow-up compared to baseline is considered a successful clinical outcome.
• Assessment of health-related quality of life with SF-12 [[12 months]]: Health-related quality of life and changes in quality of life perception will be evaluated at each follow-up visit using the SF-12 Health Survey and compared with baseline measurements. Each domain of the survey is evaluated independently. Scores for each domain range from 0 to 100, where 0 represents the worst possible health state and 100 represents the best possible health state.
• Patient satisfaction assessment [[12 months]]: Patient satisfaction will be evaluated at the final follow-up visit (12 months) using a 3-point Likert scale based on three specific questions directed to the subject. The scale consists of three response options: 'Yes', 'Undecided', and 'No'. The proportion of patients responding 'Yes' to the satisfaction questions will be analyzed to determine the overall treatment satisfaction rate.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* 18 years of age or older.
* Skeletally mature.
* Male or female.
* Undergone spinal surgery (cervical or thoracolumbar) for any indication under current medical practice.
* Titania® spinal stabilization/fusion systems and/or BONEGRAFT® bone cements or BONEGRAFT® bone graft materials used during the operation.
* No general health condition contraindicating surgery.
* No legal restriction (military service, incarceration, or equivalent).
* Provision of signed and dated Informed Consent Form (ICF)

Exclusion Criteria:

* Participation in another interventional clinical investigation
* Suspected or confirmed pregnancy
* Morbid obesity
* Neurological or psychiatric conditions preventing compliance with postoperative care and instructions
* Active spinal or systemic infection
* High fever or leukocytosis
* Severe osteoporosis and/or disease affecting bone metabolism
* Known allergy or hypersensitivity to PEEK, Titanium, or PMMA
* Congenital abnormality, tumor, or other condition preventing secure implant fixation or likely to shorten implant useful life
* Inadequate tissue coverage at the operative site
* Legally restricted individuals (military personnel, prisoners, etc.)

• Hasan Kamil Sucu, Professor, Study director, Izmir Katip Celebi University Ataturk Training and Research Hospital