(232 days)
The OsteoFab™ Patient Specific Cranial Device (OPSCD) is intended for the replacement of bony voids in the cranial skeleton.
An OsteoFab™ Patient Specific Cranial Device (OPSCD) is built individually for each patient to correct defects in cranial bone. The OPSCD is constructed with the use of the patient's CT imaging data and computer aided design to determine the dimensions of each implant. The OPSCD is built by a LASER sintering machine. The OPSCD is attached to native bone with commercially available cranioplasty fixation systems. The OPSCD is a non-load bearing single use device and it is non-sterilization instructions documented in the package insert have been validated.
This document describes the performance testing conducted for the OsteoFab™ Patient Specific Cranial Device (OPSCD). The study focuses on bench testing to establish quality control specifications and demonstrate the device's material properties meet specified acceptance criteria.
1. Table of Acceptance Criteria and Reported Device Performance
The device performance was evaluated against final QC specifications derived from 23 builds, and for different thicknesses.
Summary Statistics of 23 Builds (TABLE 1):
| Characteristic | Acceptance Criteria | Reported Device Performance (Mean) |
|---|---|---|
| Glass Transition Temperature (Tg) | 154-167 °C | 160.70 °C |
| FTIR | ≥95% Match to Designated PEKK Standard | 96.68% Match |
| Average Specific Gravity | 1.25-1.31 | 1.28 |
| Average Tensile Stress at Break (X-orientation) (KPSI) | ≥8.77 | 12.04 |
| Average Tensile Elongation @ Break (%) | ≤3.6% | 2.52% |
| Average Young's Modulus of Elasticity (KPSI) | ≥262 | 541.61 |
Tensile Strength Data for Different Thicknesses (TABLE 2 - compared to 3.2 mm Release Criteria):
| Characteristic | Release Criteria for 3.2 mm thickness | Reported Device Performance (Average) |
|---|---|---|
| 1 mm thickness | ||
| Average Tensile Stress at Break (X-orientation) (KPSI) | ≥8.77 | 10.5 |
| Average Tensile Elongation @ Break (%) | ≤3.6 | 2.4 |
| Average Young's Modulus of Elasticity (KPSI) | ≥262 | 329 |
| 2 mm thickness | ||
| Average Tensile Stress at Break (X-orientation) (KPSI) | ≥8.77 | 10.8 |
| Average Tensile Elongation @ Break (%) | ≤3.6 | 2.4 |
| Average Young's Modulus of Elasticity (KPSI) | ≥262 | 409 |
| 4 mm thickness | ||
| Average Tensile Stress at Break (X-orientation) (KPSI) | ≥8.77 | 11.6 |
| Average Tensile Elongation @ Break (%) | ≤3.6 | 2.4 |
| Average Young's Modulus of Elasticity (KPSI) | ≥262 | 490 |
Through Hole Size and Spacing Measurements (TABLE 3 & 4):
| Characteristic | Nominal Value with Tolerance | Reported Device Performance (Average) |
|---|---|---|
| 5 mm Through Hole (Diameter) | 5.00 (4.50 – 5.50) mm | 4.74 mm |
| 2 mm Through Hole (Diameter) | 2.00 (1.50 - 2.50) mm | 1.92 mm |
| 5 mm Spacing between Through Holes | 5.00 (4.50 - 5.50) mm | 4.81 mm |
| 2 mm Spacing between Through Holes | 2.00 (1.50 - 2.50) mm | 1.79 mm |
2. Sample Size Used for the Test Set and the Data Provenance
- For final QC specifications (TABLE 1): The test set was derived from 23 builds. No further information on the specific number of individual test specimens per build for each parameter is provided, but for tensile strength testing, it's mentioned that OPSCD test specimens from the 23 builds were 3.2 mm thick.
- For minimum thickness determination (TABLE 2): Three sets of 5 specimens each were used for 1 mm, 2 mm, and 4 mm thicknesses (total 15 specimens).
- For through-hole measurements (TABLE 3 & 4): 10 specimens for each through-hole size (5 mm and 2 mm) were measured for both diameter and spacing (total 20 measurements for diameter, 20 for spacing across two categories).
- Data Provenance: The data appears to be from retrospective bench testing conducted internally by Oxford Performance Materials, LLC. There is no information on the country of origin of the data beyond the manufacturer's location in South Windsor, CT, USA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
This study involves bench testing for material properties and physical specifications. Therefore, the "ground truth" is established by standardized laboratory testing procedures and predefined acceptance criteria, not by expert human graders. No experts were used in this context to establish a "ground truth" for interpretations as would be in a diagnostic imaging study.
4. Adjudication Method for the Test Set
Not applicable. As this is bench testing, there is no human adjudication process involved in reviewing the results; the results are quantitative measurements compared against predetermined numerical acceptance criteria.
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
Not applicable. This is a bench testing study for a medical device's physical and material properties, not a study evaluating human reader performance with or without AI assistance in a clinical setting.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Not applicable. This is not an AI algorithm study; it is hardware bench testing.
7. The Type of Ground Truth Used
The ground truth used for this study is based on predefined engineering specifications and material property standards. These specifications are derived from statistical analysis (mean +/- 3 standard deviations for some parameters, or a percentage match for others) established from the initial 23 builds, and industry standards for material characteristics. For the through-hole measurements, the ground truth is the nominal design value with a specified tolerance.
8. The Sample Size for the Training Set
- For establishing final QC specifications (TABLE 1): The "training set" for these specifications could be considered the 23 builds from which the mean and standard deviation values were calculated to define the acceptance criteria.
9. How the Ground Truth for the Training Set Was Established
The "ground truth" (i.e., the acceptance criteria and reference values) for the training set (the 23 builds) was established through statistical analysis of the measured outcomes from these 23 builds. For parameters like Tg, Specific Gravity, Tensile Stress, Elongation, and Young's Modulus, the acceptance criteria were defined as "Mean +/- 3SD", "Mean - 3SD", or "Mean + 3SD" based on the data from these 23 builds. For FTIR, it was a "≥95% Match to a Designated PEKK Standard". This indicates an internal reference standard was used.
§ 882.5330 Preformed nonalterable cranioplasty plate.
(a)
Identification. A preformed nonalterable cranioplasty plate is a device that is implanted in a patient to repair a skull defect and is constructed of a material, e.g., stainless steel or vitallium, that cannot be altered or reshaped at the time of surgery without changing the chemical behavior of the material.(b)
Classification. Class II (performance standards).