(28 days)
Cranioplastic® is indicated for the repair of cranial defects.
Cranioplastic® is a self-curing, methylmethacrylate (MMA) based acrylic resin, for repairing cranial defects. The following modifications are being made: A change is being made to the formulation of the liquid and powder components of the acrylic cement and the Instructions for Use (IFU) is being updated.
This section describes how the device meets the acceptance criteria. It should be noted that this device, Cranioplastic®, is a medical device (methyl methacrylate for cranioplasty) and the provided text is a 510(k) summary, which focuses on demonstrating substantial equivalence to pre-existing devices rather than on a detailed clinical study with specific acceptance criteria in the way one might evaluate a diagnostic AI algorithm. Therefore, the information typically requested for AI/software-based devices, such as sample sizes for test/training sets, expert qualifications, adjudication methods, and MRMC studies, is not applicable or available for this type of submission.
Here's an analysis based on the provided text, addressing the points where information is available:
1. A table of acceptance criteria and the reported device performance
For a material like Cranioplastic®, "acceptance criteria" are typically related to material properties and performance characteristics that demonstrate equivalence to predicate devices, rather than a single numerical performance metric (like accuracy or sensitivity) against a clinical outcome.
| Acceptance Criteria (Implied by Substantial Equivalence Basis) | Reported Device Performance (Summary of Equivalence) |
|---|---|
| Technological Characteristics: | Demonstrated similarity in: |
| - Chemical Composition | (Not explicitly detailed, but implied as similar to predicates) |
| - Material Properties | (Not explicitly detailed, but implied as similar to predicates) |
| - Performance Characteristics | (Not explicitly detailed, but implied as similar to predicates) |
| - Manufacture | (Not explicitly detailed, but implied as similar to predicates) |
| - Packaging | (Not explicitly detailed, but implied as similar to predicates) |
| - Sterilization | (Not explicitly detailed, but implied as similar to predicates) |
| Intended Use: | "repair of cranial defects" (Identical to predicates) |
| Indications for Use: | "repair of cranial defects" (Identical to predicates) |
Study Proving Device Meets Acceptance Criteria:
The "study" proving the device meets its acceptance criteria is the 510(k) premarket notification process itself. The submission argues for substantial equivalence to legally marketed predicate devices, specifically Cranioplastic® (K873689) and SmartSet GMV Endurance Gentamicin Bone Cement (K033382).
The basis for substantial equivalence is explicitly stated as its "similarity in terms of technological characteristics (chemical composition, material properties, performance characteristics, manufacture, packaging and sterilization)" to the predicate devices. The modifications made were a change to the formulation of the liquid and powder components and an update to the Instructions for Use (IFU). The FDA's issuance of the 510(k) clearance signifies their agreement that this substantial equivalence has been demonstrated.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
Not applicable. This is a material science and engineering equivalence submission, not a human reader or AI performance study. There isn't a "test set" in the context of clinical images or patient data. The "testing" involved demonstrating that the modified formulation's properties are comparable to the predicate devices and suitable for the intended use.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
Not applicable. Ground truth, in the AI/radiology sense, is not relevant here. The "ground truth" for this device is its material characteristics and its functional performance in repairing cranial defects, which is evaluated through engineering and chemical testing, and clinical use history of similar predicate devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. There is no test set in the clinical evaluation sense, and therefore no adjudication method for human readers.
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 not an AI-assisted diagnostic device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is not an algorithm or software device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" in this context would be established through:
- Material specifications and testing: Chemical composition analysis, mechanical property testing (e.g., strength, setting time), biocompatibility testing. These are compared against established standards for medical implants and against the properties of the predicate devices.
- Clinical history of predicate devices: The long-standing safe and effective use of the predicate devices for cranial repair provides the "ground truth" that methyl methacrylate is an appropriate material for this application. The sponsor demonstrates that their modified device maintains these established characteristics.
8. The sample size for the training set
Not applicable. There is no training set in the context of machine learning.
9. How the ground truth for the training set was established
Not applicable. There is no training set.
§ 882.5300 Methyl methacrylate for cranioplasty.
(a)
Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of surgery, the surgeon initiates polymerization of the material and forms it into a plate or other appropriate shape to repair the defect.(b)
Classification. Class II (performance standards).