(224 days)
The OsteoFab™ Patient Specific Facial Device (OPSFD) is designed individually for each patient for enhancement, to correct trauma, and/or to correct defects in facial bone. The OPSFD is also designed individually for non-load bearing enhancement of mandibular bone.
An OsteoFab® Patient Specific Facial Device (OPSFD) is built individually for each patient. The OPSFD is made of polyetherketone (PEKK) polymer and built by a LASER sintering machine. The OPSFD is constructed with the use of the patient's CT imaging data and computer aided design to determine the dimensions of each implant. OPSFDs come in a variety of configurations that depend on the geometry of the application. OPSFDs are oblong and (for an individual patient) have shapes and sizes that vary within the following specifications: (1) maximum diameter is 20 cm (2) minimum thickness is 1 mm, (3) maximum thickness is 10 mm, (4) maximum open density is 25%, (5) minimum as built hole diameter is 3 mm, (6) maximum as built hole diameter is 5 mm, and (6) minimum distance from the edge of an as built hole to the edge of a device is 15 mm.
The OPSFD is attached to native bone with commercially available fixation systems and it is a permanent implant. The OPSFD is a non-load bearing single use device and it does not impart mechanical strength to the implant area. The OPSFD implant is shipped non-sterile and the sterilization recommendations documented in the instructions for use (IFU) are according to ANSI/AAMI ST79 "Comprehensive Guide to Steam Sterility Assurance in Health Care Facilities" have been validation for gravity displacement steam sterilization was conducted at 135°C (275°F) with a half cycle of five (5) minutes. The validation for prevacuum steam sterilization was conducted at 132°C (270°F) with a half cycle of two (2) minutes.
The provided text describes specific bench testing for the OsteoFab® Patient Specific Facial Device (OPSFD), which is an individually designed implant made of polyetherketone (PEKK) polymer. The document focuses on demonstrating the substantial equivalence of the OPSFD device to previously cleared predicate devices by comparing various material and performance characteristics.
Here’s a breakdown of the acceptance criteria and the studies that prove the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are primarily derived from the quality control (QC) specifications established for the device's manufacturing process, as well as comparisons to predicate devices and recognized ASTM standards.
| Characteristic | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| I. Quality Control (Manufacturing) | ||
| Glass Transition Temperature (Tg) | 157-160 °C | Mean: 158.16 °C (Within range) |
| Fourier Transform Infrared Spectroscopy (FTIR) | ≥ 95% Match to a designated PEKK standard | Mean: 98.11% Match (Meets criterion) |
| Average Specific Gravity | 1.27-1.31 | Mean: 1.29 (Within range) |
| Average Tensile Stress at Break (X-orientation) | ≥ 9.0 KPSI | Mean: 11.67 KPSI (Meets criterion) |
| Average Tensile Elongation @ Break | ≥ 1.5 % | Mean: 2.63% (Meets criterion) |
| Average Young's Modulus of Elasticity | ≥ 281 KPSI | Mean: 509.09 KPSI (Meets criterion) |
| II. Device Specific Performance | ||
| Wall Thickness (Tensile Strength) | For 1mm, 2mm, 4mm thick specimens, tensile strength values must be substantially equivalent to 3.2mm QC release criteria (Tensile Stress ≥ 9.0 KPSI, Elongation @ Break ≥ 1.5 %, Young's Modulus ≥ 281 KPSI). | 1mm thickness: Tensile Stress = 10.5 KPSI, Elongation = 2.4 %, Young's Modulus = 329 KPSI. 2mm thickness: Tensile Stress = 10.8 KPSI, Elongation = 2.4 %, Young's Modulus = 409 KPSI. 4mm thickness: Tensile Stress = 11.6 KPSI, Elongation = 2.4 %, Young's Modulus = 490 KPSI. (All met or exceeded 3.2mm release criteria, establishing 1mm as minimum allowable thickness). |
| Through Hole Size | Manufacturable range of 2mm to 5mm. | Average diameter for 5mm nominal holes: 4.74 mm (Tolerance 4.50-5.50 mm). Average diameter for 2mm nominal holes: 1.92 mm (Tolerance 1.50-2.50 mm). (Demonstrated manufacturability within the specified range). |
| Spacing between Through Holes | Minimum spacing of 2mm. | Average spacing for 5mm nominal spacing: 4.81 mm (Tolerance 4.50-5.50 mm). Average spacing for 2mm nominal spacing: 1.79 mm (Tolerance 1.50-2.50 mm). (Demonstrated manufacturability of the specified minimum spacing). |
| Screw Insertion (Fractures) | Self-drilling screws: Limited fractures (e.g., 0/28 for straight edge, 2/28 for 45° angle) Self-tapping screws (with pilot hole): No fractures. | Self-drilling: 0/28 fractures (straight edge), 2/28 fractures (45° angle). Self-tapping: 0/28 fractures (straight edge), 0/28 fractures (45° angle). (Acceptable performance, particularly for self-tapping). |
| Drop Characterization (Material Loss/Damage) | Material loss ≤ 0.020%. No significant damage (e.g., major fractures) after inspection. | Horizontal, dome up: 0.020% material loss. Horizontal, dome down: 0.002% material loss. Vertical: 0.008% material loss. All showed only "slight indentation on the point of impact" at 10x inspection. (Met criteria for minimal material loss and damage). |
| Edge Distance (Cracks from Screws) | No cracks when screw centerline to edge distance is sufficient. | Rev A (3.75mm screw centerline to edge, pre-drilled, self-tapping): 4/45 cracked. Rev B (5mm screw centerline to edge, pre-drilled, self-tapping): 45/45 no cracks. Rev C (5mm screw centerline to edge, no pre-drilling, self-drilling): 1/6 cracked (study discontinued). Rev D (7mm screw centerline to edge, no pre-drilling, self-drilling): 45/45 no cracks. (Demonstrates acceptable performance with sufficient edge distance and/or pre-drilling). |
| Modification (Edge Modification/Re-contouring) | Power tools should not cause excessive melting or instability. Cutting should be effective. | Diamond burr light pressure: No issues. Diamond burr heavy pressure: Debris melted locally. Deep flute light pressure: No problems. Deep flute heavy pressure: Burr head unstable. Sagittal saw: Edge cutting easy, surface cutting not as easy. Reciprocating saw: Edge and surface cutting easy. (Indicates acceptable modification methods with appropriate technique). |
| Dimensional Stability (Sterilization cycles) | After multiple sterilization cycles, ≥ 99% of datum points within ± 0.005 inches of pre-sterilization scans. No cracking, fracturing, swelling, or shrinkage. | After 3 sterilization cycles: ≥ 99% of datum points within ± 0.005 inches. No cracking, fracturing, swelling, or shrinkage. After 9 sterilization cycles: ≥ 99% of datum points within ± 0.005 inches. No cracking, fracturing, swelling, or shrinkage. (Demonstrated excellent dimensional stability). |
| Axial Pullout Force | Stronger than PMMA and PEEK predicate materials. | PEKK (Steam x 1, multiple batches): 244.0 N, 227.1 N, 233.1 N 평균. PMMA (Gamma x 1): 43.5 N. PEEK (Steam x 1): 193.6 N. (PEKK significantly stronger than both PMMA and PEEK). |
| Tensile Strength (vs. PMMA Predicate) | Tensile at Break (ASTM D638): ≥ 9,000 psi. Elongation at Break (ASTM D638): ≥ 1.5 %. | OPSFD (PEKK): Tensile at Break ≥ 9,000 psi (QC data), Elongation at Break ≥ 1.5% (QC data). PMMA (ASTM D4802): Nominal Tensile at Break = 9,000 psi, Nominal Elongation at Break = 2%. (Demonstrated substantial equivalence in tensile strength between PEKK and PMMA). |
| Biocompatibility | Within acceptance criteria of ISO 10993-3, 5, 6, 10, 11, and 18 standards. | Test results obtained from PEKK test specimens were found to be within acceptance criteria described in the ISO 10993-3, 5, 6, 10, 11, and 18 standards. Cytotoxicity results for L-929 mouse fibroblast cells and human neuroblastoma SK-N-MC cells were within ISO 10993-5 criteria. |
| Endotoxin | Below medical device contacting cerebral spinal fluid acceptance criterion (10 through holes) for hole size and spacing. |
- Screw Insertion: PEKK test blocks (3mm thick, 14 fingers each). For self-drilling & self-tapping experiments, 28 screw insertions were made for straight edges and 45° angle edges in each instance.
- Drop Characterization: N=1 for each of three configurations (horizontal dome up, horizontal dome down, vertical).
- Edge Distance:
- Rev A: Three PEKK test blocks (job 2820), 45 screw insertions.
- Rev B: Four PEKK test blocks (job 2843), 45 screw insertions.
- Rev C: One PEKK test block (job 2849), 45 screw insertions (study discontinued).
- Rev D: Four PEKK test blocks (job 2849), 45 screw insertions.
- Modification: N=2 for each experiment type (edge modification, re-contouring, cutting).
- Dimensional Stability: 10 cranial flap test specimens for 3 sterilization cycles and 10 cranial flap test specimens for 9 sterilization cycles.
- Axial Pullout Force:
- PMMA: 20 test specimens.
- PEKK (Steam x 1, two different runs): 10 test specimens each.
- PEKK (Steam x 1, 2, 3 cycles, two different runs): 8 test specimens per sterilization condition per run (total 48 PEKK specimens across these two experiments).
- PEEK: 10 test specimens.
- Tensile Strength (vs. PMMA Standard): The OPSFD data is derived from the N=32 QC builds. PMMA data is from ASTM D4802.
- Biocompatibility: PEKK test specimens (specific numbers not provided for each test but generally typical for ISO 10993 evaluations).
- Endotoxin: OsteoFab® test specimens (specific numbers not provided).
Data Provenance: All data appears to be from prospective bench testing conducted by Oxford Performance Materials, Inc. (the manufacturer). There is no indication of country of origin for the data other than it being generated by the submitting company.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This is a materials science and mechanical engineering evaluation, not a clinical study involving diagnosis or interpretation of patient data. Therefore, the concept of "experts establishing ground truth" in a clinical sense (e.g., radiologists) does not apply.
Instead, the "ground truth" or acceptance criteria are established based on:
- Industry standards (e.g., ASTM D638, ASTM F543-07, ISO 10993, USP 85, ANSI/AAMI ST79).
- Internal quality control data (e.g., 32 builds used to set QC specifications).
- Comparison to predicate device characteristics where information was available (e.g., PMMA and PEEK tensile strength and pullout force).
The "experts" involved would be the material scientists, engineers, and regulatory specialists who designed, executed, and analyzed these bench tests, ensuring compliance with relevant standards and demonstrating equivalence. Their specific qualifications are not detailed in this summary.
4. Adjudication Method for the Test Set
Not applicable. This is not a clinical study involving human readers or interpretations needing adjudication. The results are quantitative measurements against predefined criteria or comparative measurements against other materials/devices.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
No, this is a physical device (implant) and materials performance evaluation, not an AI or imaging diagnostic device. Therefore, MRMC studies and AI assistance metrics are not applicable.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Not applicable. This is a physical implant, not an algorithm.
7. The Type of Ground Truth Used
The "ground truth" for the performance evaluations is based on:
- Metrology: Direct measurements of physical properties (e.g., tensile strength, specific gravity, dimensions, pullout force) using calibrated instruments.
- Standardized Test Methods: Adherence to internationally recognized standards (e.g., ASTM, ISO, USP) for testing methodologies.
- Visual Inspection: Microscopic or macroscopic visual inspection (e.g., 10x magnification for cracks, indentations).
- Chemical Analysis: FTIR for material identification and purity.
- Biocompatibility Definitions: Established criteria within ISO 10993 series.
- Comparative Data: Published nominal values for predicate materials (e.g., PMMA from ASTM D4802).
8. The Sample Size for the Training Set
Not applicable in the context of machine learning. This is a physical device.
For the purpose of establishing manufacturing quality control specifications, the "training set" (or rather, the data used to define the process's stable limits) for the final QC tests was based on 32 builds.
9. How the Ground Truth for the Training Set Was Established
Again, this refers to establishing manufacturing quality control specifications rather than AI model training. The "ground truth" for these specifications was established by:
- Statistical Analysis of Production Data: The mean, standard deviation, and 3 standard deviations (3SD) were calculated from the 32 builds for the various QC parameters (Tg, FTIR, Specific Gravity, Tensile Stress, Elongation, Young's Modulus).
- Engineering Judgment and Safety Margins: The acceptance criteria were then defined based on these statistical measures (e.g., Mean +/- 3SD, or Mean - 3SD for minimum performance characteristics), indicating a robust manufacturing process and ensuring product quality and safety. For FTIR, a ≥ 95% match to a designated PEKK standard was set.
§ 878.3500 Polytetrafluoroethylene with carbon fibers composite implant material.
(a)
Identification. A polytetrafluoroethylene with carbon fibers composite implant material is a porous device material intended to be implanted during surgery of the chin, jaw, nose, or bones or tissue near the eye or ear. The device material serves as a space-occupying substance and is shaped and formed by the surgeon to conform to the patient's need.(b)
Classification. Class II.