(28 days)
NanOss Bone Void Filler is intended only for bony voids or gaps that are not intrinsic to the stability of the bony structure. The product is indicated to be gently packed into bony voids or gaps of the skeletal system (i.e., the extremities, spine and pelvis). These defects may be surgically created osseous defects or osseous defects created from traumatic injury to the bone. The product provides a bone void filler that resorbs and is replaced by the growth of new bone during the healing process.
NanOss Bone Void Filler is an osteoconductive, resorbable, calcium phosphate implant for use as a bone graft substitute or bone void filler. The device consists of prefabricated cylindrical calcium phosphate pellets. The device is radiopaque and is presterilized for single use. The nanocrystalline processing of the material results in sintered hydroxyapatite pellets that are translucent and uniform in density and strength.
This 510(k) premarket notification for the Angstrom Medica NanOss™ Bone Void Filler does not contain the detailed study information typically required to describe acceptance criteria and device performance in the context of AI/ML or diagnostic devices. Instead, it is a submission for a bone void filler product, which is a medical device, but not one that involves software algorithms, AI, or diagnostic performance metrics like sensitivity, specificity, or accuracy.
Therefore, many of the requested categories (e.g., sample size for test set, number of experts, adjudication method, MRMC studies, standalone performance, training set details) are not applicable to this type of device submission as they pertain to performance evaluation of diagnostic or AI-driven systems.
However, based on the provided document, I can extract information relevant to the device's equivalence to marketed products, which serves as the "proof" for this type of device, rather than a performance study against acceptance criteria in the AI/ML sense.
Here's a breakdown based on the information available:
1. A table of acceptance criteria and the reported device performance
For this type of device, "acceptance criteria" are not reported as specific performance metrics and thresholds (like sensitivity > X%). Instead, the acceptance criteria are met by demonstrating substantial equivalence to predicate devices. The "reported device performance" is essentially that it is chemically, functionally, and indication-wise similar to already cleared devices.
| Acceptance Criteria Category | Description of how criteria are met (Reported Device Performance) |
|---|---|
| Intended Use Equivalence | NanOss Bone Void Filler is intended for bony voids or gaps not intrinsic to bony structure stability, for filling defects in the skeletal system (extremities, spine, pelvis), and to resorb and be replaced by new bone. This is substantially the same as the intended use of the predicate devices. |
| Design Principles Equivalence | NanOss Bone Void Filler is an osteoconductive, resorbable, calcium phosphate implant for use as a bone graft substitute or bone void filler, consisting of prefabricated cylindrical calcium phosphate pellets, radiopaque, and presterilized. These design principles are substantially the same as the predicate devices. |
| Functional Characteristics Equivalence | NanOss Bone Void Filler pellets are chemically similar to calcium phosphate predicates, exhibiting expected phase purity, calcium/phosphorus stoichiometry, and trace element levels below ASTM F1185 limits. Density is essentially theoretical for ceramic hydroxyapatite, and bulk density is in the expected range for small cylindrical pellets. Dissolution behavior is within the range of predicate devices. |
| Material Composition Equivalence | Chemically similar to calcium phosphate predicates (hydroxyapatite), meeting phase purity and stoichiometry expectations, and trace element levels below ASTM F1185. |
| Regulatory Classification Equivalence | Classified as Class II, Special Controls, under 21 CFR 888.3045 (Resorbable calcium salt bone void filler device), which aligns with predicates. Calcium phosphate devices have been cleared as substantially equivalent to calcium sulfate devices. |
2. Sample sized used for the test set and the data provenance
- Not Applicable. This submission relies on demonstrating equivalence to predicate devices, not on a "test set" in the context of AI/ML performance evaluation studies. Chemical and physical properties of the NanOss pellets would have been tested, but these are not clinical "test sets" of data as understood in AI/ML.
- Data Provenance: The document doesn't specify an external "data provenance" for performance testing, as the "proof" is largely based on internal material characterization and comparison to established predicate properties.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. No ground truth in the AI/ML sense (e.g., expert consensus on images or pathology results) was established for a "test set." The basis for clearance is material science and clinical equivalence to existing products.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not Applicable. No adjudication method for a "test set" was used as described for AI/ML performance studies.
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 a diagnostic device involving human readers or AI assistance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not Applicable. This is a physical bone void filler, not an algorithm.
7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)
- For material properties and claims of equivalence: The "ground truth" is established based on standard material characterization techniques (e.g., chemical analysis, density measurements, dissolution studies) and comparison to the known properties and regulatory clearances of the predicate devices.
- For clinical benefit: The "ground truth" is that similar calcium phosphate/sulfate bone void fillers are already cleared and used safely and effectively in clinical practice, and this new device functions equivalently.
8. The sample size for the training set
- Not Applicable. No training set for an AI/ML algorithm was used.
9. How the ground truth for the training set was established
- Not Applicable. No training set for an AI/ML algorithm was used.
Summary of the "Study" that Proves Acceptance Criteria are Met:
The "study" in this context is the demonstration of substantial equivalence to legally marketed predicate devices. The manufacturer, Angstrom Medica, Inc., submitted evidence to the FDA showing that their NanOss™ Bone Void Filler shares the same intended use, design principles, and functional characteristics as several already cleared bone void fillers.
Key elements of this "study" (as implied by the document):
- Comparison to Predicate Devices: NanOss was compared to:
- Material Characterization: Evidence was presented that NanOss pellets are:
- Chemically similar to calcium phosphate predicates.
- Exhibit expected phase purity and calcium/phosphorus stoichiometry.
- Have trace element levels below ASTM F1185 limits.
- Possess a density approaching theoretical density for ceramic hydroxyapatite.
- Have a bulk density in the expected range for small cylindrical pellets.
- Demonstrate dissolution behavior within the range of predicate devices.
The FDA's letter (K050025) confirms that, based on this submission, the device was determined to be "substantially equivalent" to the predicate devices for the stated indications for use, thereby meeting the regulatory acceptance criteria for market clearance.
§ 888.3045 Resorbable calcium salt bone void filler device.
(a)
Identification. A resorbable calcium salt bone void filler device is a resorbable implant intended to fill bony voids or gaps of the extremities, spine, and pelvis that are caused by trauma or surgery and are not intrinsic to the stability of the bony structure.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for Industry and FDA.” See § 888.1(e) of this chapter for the availability of this guidance.