(239 days)
DBX® is intended for use as a Demineralized Bone Matrix for voids or gaps that are not intrinsic to the stability of the bony structure. It can be used in the:
| Putty | Mix | Paste |
|---|---|---|
| Extremities | Extremities | Extremities |
| Pelvis | Pelvis | Pelvis |
| Posterolateral Spine | Spine | |
| Cranium |
DBX® is indicated for treatment of surgically created osseous defects or osseous defects created from traumatic injury. DBX® Putty can be used as an extender in the spine with autograft. DBX® can be used with bone marrow. DBX® is for single patient use only.
DBX® Demineralized Bone Matrix is available in three forms: Paste, Putty and Mix. DBX® products are completely resorbable. DBX® Paste and Putty are composed of donor cortical bone; the DBX® Mix is composed of donor corticocancellous bone. The bone granules are mixed with sodium hyaluronate (Hy) in varying combinations to form the DBX® Putty, Paste, and Mix.
This 510(k) summary describes a change in the osteoinductivity assay for the DBX® Demineralized Bone Matrix Putty, Paste, and Mix. The device itself is a bone void filler containing human demineralized bone matrix (DBM). The primary focus of the provided document is on the validation of the new osteoinductivity assay as a surrogate for the previously accepted in vivo athymic mouse model, not a study of the overall clinical performance of the device.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based solely on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (for Osteoinductivity Assay) | Reported Device Performance (for this specific change) |
|---|---|
| Predicate Assay (In Vivo Athymic Mouse Model): Must prove positive for lot release (K040262) | N/A (this is the old assay, but the new assay aims to correlate with it) |
| New Assay (In Vitro BMP-2 ELISA): Must prove positive for lot release when used as a surrogate for the athymic mouse model. | Results from the immunoassay were correlated to the athymic mouse model for the DBM alone and the DBX® Putty. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly provide a "test set" sample size in the traditional sense of a clinical study for device performance. Instead, it discusses the validation of an assay.
-
Athymic Mouse Model (In Vivo): Used for original and ongoing validation.
- Sample Size: Not specified (e.g., number of mice, number of lots tested).
- Data Provenance: Not specified, but likely laboratory-based.
- Retrospective/Prospective: Not specified for individual tests, but implies ongoing lot testing.
-
BMP-2 ELISA (In Vitro): This is the new assay being validated against the athymic mouse model.
- Sample Size: "Every final lot of DBX® Putty is tested" or "each lot of DBM incorporated into DBX® Putty is assayed." The number of lots used specifically for the correlation study between the ELISA and the athymic mouse model is not specified.
- Data Provenance: Laboratory testing.
- Retrospective/Prospective: The correlation study would have been prospective to establish the link between the new and old methods. Subsequent lot testing would be prospective for quality control.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This information is not provided. The "ground truth" here is the osteoinductive potential, as measured by either the athymic mouse model or the BMP-2 ELISA. These are laboratory assays, not interpretations by experts in a clinical context.
4. Adjudication Method for the Test Set
Not applicable. This is not a study requiring adjudication of clinical outcomes or image interpretations. The "adjudication" in this context is the comparison between the results of the in vitro ELISA and the in vivo athymic mouse model. The document states that "Results from this immunoassay were correlated to the athymic mouse model." The specific statistical method or criteria for this correlation are not detailed beyond the statement of correlation.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC study was not done. This device is a bone graft substitute, and the submission concerns a change in a laboratory assay for osteoinductivity, not a diagnostic imaging or clinical assessment device that would typically involve an MRMC study.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, in a way. The "standalone" performance here refers to the new BMP-2 ELISA assay. The study establishes its correlation with the athymic mouse model, suggesting it can function as a standalone test for osteoinductivity in lot release.
7. The Type of Ground Truth Used
The ground truth for determining osteoinductive potential is:
- Biological Assay: The in vivo athymic mouse model. This model has a history of use for assessing osteoinductivity.
- Biochemical Assay: The BMP-2 ELISA, which is being proposed as a surrogate for the biological assay. The "ground truth" for the validation of the ELISA is therefore the athymic mouse model's results.
8. The Sample Size for the Training Set
The document does not explicitly refer to a "training set" in the context of machine learning or algorithm development. The "correlation" between the BMP-2 ELISA and the athymic mouse model implicitly involves a dataset of DBM lots for which both tests were performed. The size of this dataset (i.e., the number of lots used to establish the correlation) is not specified.
9. How the Ground Truth for the Training Set Was Established
The "ground truth" for the training/correlation set (the lots used to compare the two assays) was established by:
- Athymic Mouse Model: Historically, this in vivo model was used to determine the osteoinductive potential of DBM. "Standard testing performed in an athymic mouse model... must prove positive for lot release."
- The BMP-2 ELISA results were then compared to these established athymic mouse model results to show correlation. The document implies that the positive/negative outcome of the athymic mouse model served as the gold standard for validating the ELISA's accuracy in predicting osteoinductivity.
§ 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.