a-BSM™ Bone Substitute Material is a synthetic calcium phosphate hydroxyapatitic material intended to be implanted for use in the filling, repair, reconstruction and augmentation of burr holes, contiguous craniotomy cuts, and other defects in craniofacial bones including fronto-orbital, malar and mental areas with a surface area no larger than 25cm2.
Device Story
a-BSM™ is a synthetic, self-setting calcium phosphate hydroxyapatitic powder. Clinician mixes powder with sterile saline in an elastomeric bulb via manual kneading to create a moldable paste. Paste is applied to craniofacial bone defects (burr holes, craniotomy cuts, fronto-orbital/malar/mental areas) during surgery. Material hardens in situ at body temperature in approximately one hour. Device is intended for single-use, permanent implantation; it resorbs over time and is replaced by natural bone. Benefits include restoration of bony contour and defect repair without requiring autograft. No biological substances or preservatives are used.
Clinical Evidence
Evidence includes bench-top physico-chemical characterization and a one-year canine femoral defect study. Bench testing confirmed chemical/crystalline composition and solubility similar to predicate. In vivo study (canine model) compared a-BSM™ to autograft; results showed equivalent new bone replacement and remodeling at all timepoints. Biomechanical strength (torsion loading to fracture) was equivalent to autograft. Biocompatibility testing included Ames test, micronucleus test, hemolysis, MEM elution, systemic toxicity, sensitization, pyrogenicity, and intracutaneous toxicity, all showing no adverse effects.
Technological Characteristics
Synthetic calcium phosphate hydroxyapatitic powder. Hardens via nonexothermic reaction in aqueous environment at 37°C. Supplied as sterile kit with elastomeric mixing bulb, syringe, needle, and saline. Dimensionally stable during setting. Resorbable. No biological components or preservatives.
Indications for Use
Indicated for filling, repair, reconstruction, and augmentation of craniofacial bone defects (burr holes, craniotomy cuts, fronto-orbital, malar, and mental areas) with surface area ≤ 25cm2.
Regulatory Classification
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.
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NOV 25 1998
K983009
# 510(k) SUMMARY
## a-BSMTM Bone Substitute Material for Cranioplasty
#### SUBMITTER INFORMATION 1.
- 1.1 Name: ETEX Corporation
- 1.2 ETEX Corporation Address: University Park at MIT 350 Massachusetts Avenue, 4th Floor Cambridge, Massachusetts 02139 U.S.A.
- 1.3 Telephone: 617-577-7270 FAX: 617-577-7170
- 1.4 Contact: Michael Schuttenberg Director, Quality Assurance / Regulatory Affairs 1.5 Summary
- Monday, November 16, 1998 Preparation Date:
#### DEVICE INFORMATION 2.
- a-BSMTM Bone Substitute Material for Cranioplasty 2.1 Proprietary Name:
- Bone Graft Material, Bone Cement, Bone Substitute 2.2 Common Names: Material
- 2.3 Classification Methyl Methacrylate for Cranioplasty, Code GXP Name and Code: Predicate Device: BoneSource™ Hydroxyapatite Cement 2.4 K953339, Osteogenics, Inc. 510(k) No.:
#### 2.5 Description of Device
ETEX x-BSM™ Bone Substitute Material for Cranioplasty is a self-setting, synthetic calcium phosphate hydroxyapatitic powder that hardens in an aqueous environment at body temperature. The a-BSMM powder is mixed with saline at the time of use and the resulting paste is applied directly to the defect site. Prior to implantation, it remains moldable for several hours. After implantation, the material hardens in approximately one hour. The material is dimensionally stable during setting, and has been demonstrated to be highly biocompatible with mammalian tissues. After implantation, the material resorbs and is replaced by natural bone.
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As supplied, each transparent plastic pouch of a-BSMTM Bone Substitute Material contains a unit dose of sterile a-BSM™ Bone Substitute Material (dry white powder) contained within an elastomeric mixing bulb (available in 0.5, 1.0, 2.5, 5.0, 10 and 25 gram dose sizes); a sterile syringe, a 16 gauge needle, and a vial containing sterile saline; and Instructions for Use. The saline is injected aseptically into the mixing bulb and the material is mixed by kneading the bulb with the fingers. The material can be shaped into the desired form prior to application or shaped in situ in the defect. &-BSM™ Bone Substitute Material is synthesized from reagent grade inorganic raw materials composed of salts of calcium and phosphates. There are no substances of biological origin used in the synthesis or processing of the product. No additional preservatives or medicinal substances are present.
#### 2.6 Intended Use
a-BSM™ Bone Substitute Material is a synthetic calcium phosphate hydroxyapatitic material intended to be implanted for use in the filling, repair, reconstruction and augmentation of burr holes, contiguous craniotomy cuts, and other defects in craniofacial bones including fronto-orbital, malar and mental areas with a surface area no larger than 25cm3.
It is intended for single use, permanent implantation. It is supplied in sterile kit form, and is not intended to be resterilized. Use of a-BSM™ Bone Substitute Material with other legally marketed devices for these indications has not yet been evaluated. a-BSMM Bone Substitute Material is not designed or sold for any use except as indicated.
#### 2.7 Substantial Equivalence to Predicate Device
a - BSM™ Bone Substitute Material is believed to be substantially equivalent to BoneSource™ in terms of design, materials, function, and intended use. Both materials are sterile, self-setting calcium phosphate powders that cure into hydroxyapatite after addition of an aqueous vehicle. This similarity in composition results in a similar degree of biocompatibility for both products. Both materials set in nonexothermic reactions. Both materials are intended for non-load-bearing bone defect filling indications in the craniofacial area. The information below briefly discusses those tests performed that support a determination of substantial equivalence.
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NOV 19 1998 17:42 FR ETEX CORP
#### TESTING USED FOR SUBSTANTIAL EQUIVALENCE EVALUATION 3.
#### 3.1 Physico-Chemical Testing
Analyses were performed on the predicate device to determine its chemical and crystalline composition relative to the characterization of a-BSM™ Bone Substitute Material. These tests included Fourier Transformed Infrared Spectroscopy, X-ray Diffraction Analysis, Calcium: Phosphorus ratio, Solubility Determination and mechanical properties. Companson of the results of these tests indicate very similar composition, nearly identical crystallinity, and similar solubility - both materials are very nearly insoluble.
Both materials consist of salts of calcium phosphate which, when mixed in an aqueous environment and allowed to harden at body temperature, cure into hydroxyapatite in nonexothermic reactions. Comparing infrared spectroscopy results of both products supports the premise that the type and level of chemical bonding is very similar between the two products. In X-ray Diffraction analysis of the two products, comparison demonstrates that both materials are composed of Hydroxyapatite in the crystalline phase and largely predominant portion of the samples, with both containing an amorphous component. Calcium : phosphorus ratios of the two products were determined and found to be similar. A comparison of solubility properties of the two products was made on hardened samples under simulated physiologic conditions. The results indicate that both materials are only slightly soluble. ETEX believes these results are strongly suggestive of chemically and physically equivalent products.
#### 3.2 Biocompatibility
A variety of tests and evaluations were performed on a-BSM™ to ascertain possible effects of the introduction of this material into mammalian systems or tissues. The tests performed and brief results or conclusions are listed below.
## Mutation Assay (Ames Test)
No increase in mutation reversion frequencies were observed.
#### Micronucleus Test
No clastogenic effects (chromosome breakage) were noted.
#### Hemolysis Assay
No negative effects observed. In fact, a-BSM™ treated samples showed a decrease in hemolysis.
510(k) Summary - Page 3 of 6 ETEX 510(k) for a-BSM™ Bone Substitute Material for Cranioplasty
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## MEM Elution Test
This test of cytotoxicity showed no negative effects.
## USP Systemic Toxicity Test
No negative systemic effects observed.
## Delayed Contact Sensitization Test
This test of skin sensitization showed no effects beyond that of control articles.
#### Pyrogen Test
a-BSM™ was determined to be nonpyrogenic by the rabbit pyrogen test.
## Intracutaneous Toxicity Test
After injection of a-BSM™ extracts, there was no evidence of irritation or toxicity beyond that of control articles.
## Muscle Implantation
Two weeks after implantation of x-BSM™ into rabbit muscle sites, there was no macroscopic evidence of tissue irritation. Microscopic evaluation showed slight cellular effects when compared with control articles.
## Bacterial Endotoxin (LAL) Evaluation
This alternate method of testing for pyrogenic effects of an article showed no measurable endotoxins in a-BSM™, and demonstrated that the product did not artificially affect the test results by inhibition or activation of the reagents used.
#### Chronic Safety/Efficacy Study
One year after implantation of x-BSM™ into surgically created bone defects in dog femurs, clinical and histopathologic evaluation of the repair sites demonstrated that new bone growth had occurred to an extent equal to that of autografts, and included remodeling of the bone tissue. There were no significant adverse findings.
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## Histology and Histomorphometry Evaluation
A comparative in vivo study with a-BSM™ and autograft implanted into a canine femoral defect model demonstrated equivalent new bone replacement of the implant material at each timepoint for this one year study.
## Biomechanical Strength Testing
In a comparative study with a-BSM™ and autograft as bone substitute materials in a canine femoral defect model, the biomechanical strength (torsion loading to fracture) of the samples were equivalent at each timepoint for this one year study.
#### Conclusions of Testing 3.3
The physico-chemical testing and biocompatibility evaluation performed on a-BSM™ Bone Substitute Material for Cranioplasty demonstrate that it is similar to the predicate device in terms of its chemical and crystalline composition, and that it shows an excellent biocompatibility and safety profile, with no significant adverse observations on any of a variety of subcellular, cellular, tissue, and systemic challenges.
For the above reasons, which are summarized in the following table comparing equivalence factors, ETEX believes that a-BSM™ Bone Substitute Material is substantially equivalent to BoneSource™ and possesses no properties which raise additional questions of safety relating to the intended use of the product.
.
.
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# COMPARISON TABLE OF SUBSTANTIAL EQUIVALENCE
| ITEM | α-BSM™ | BoneSource™ |
|---------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Design | Self-setting calcium<br>phosphate cement which<br>hardens in aqueous<br>environment at 37 °C | Self-setting calcium<br>phosphate cement which<br>hardens in aqueous<br>environment at 37 °C |
| Composition, after<br>hardening | Hydroxyapatite, with<br>amorphous component | Hydroxyapatite, with<br>amorphous component |
| Intended Use | Use in the filling, repair,<br>reconstruction and<br>augmentation of burr holes,<br>contiguous craniotomy cuts,<br>and other defects in<br>craniofacial bones including<br>fronto-orbital, malar and<br>mental areas with a surface<br>area no larger than 25cm2. | Use in the repair of<br>neurosurgical burr holes,<br>contiguous craniotomy cuts<br>and other cranial defects<br>with a surface area no larger<br>than 25 cm2 per defect.<br>BoneSource is also indicated<br>for augmentation or<br>restoration of bony contour<br>in the craniofacial skeleton<br>including the fronto-orbital,<br>malar and mental areas. |
| How Supplied | Sterile, nonpyrogenic<br>powder contained in<br>elastomeric mixing bulb to<br>be mixed at time of<br>implantation. | Sterile, nonpyrogenic<br>powder contained in vial to<br>be mixed at time of<br>implantation. |
| Preparation Method | Sterile saline injected into<br>mixing bulb, powder mixed<br>by kneading bulb, paste<br>removed and implanted. | Powder placed into mixing<br>vessel, sterile solution<br>added, powder mixed with<br>spatula, paste implanted |
| Pot Life after mixing | Does not harden at room<br>temperature, if moist | 5 - 30 minutes dependent<br>upon diluent |
| Hardening Time in body | One hour | Up to four hours |
| Solubility Product | $6 x 10^{-54}$ | $6 x 10^{-67}$ |
# α-BSMTM and BoneSource™
ETEX 510(k) for a-BSM™ Bone Substitute Material for Cranioplasty
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Image /page/6/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized caduceus symbol, which is a staff with two snakes coiled around it. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES-USA" are arranged in a circular pattern around the caduceus symbol. The logo is black and white.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
# NOV 2 5 1998
Mr. Michael Schuttenberg Director, Quality Assurance and Regulatory Affairs ETEX Corporation 350 Massachusetts Avenue, 4th Floor Cambridge, Massachusetts 02139
K983009 · Re: Trade Name: α-BSM™ Bone Substitute Material for Cranioplasty Requlatory Class: II Product Code: GXP Dated: August 26, 1998 Received: Auqust 28, 1998
Dear Mr. Schuttenberg:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical General regulation (21 CFR Part 820) and that, Devices: through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in regulatory In addition, FDA may publish further announcements action. concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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#### Page 2 - Mr. Michael Schuttenberg
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".
Sincerely yours,
Celia M. Witten, Ph.D., M.D.
Director
Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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# PREMARKET NOTIFICATION
# DEVICE NAME AND INTENDED USE STATEMENT
Device Name: a-BSMTM Bone Substitute Material for Cranioplasty
## Indications/ Intended Uses:
a-BSM™ Bone Substitute Material is a synthetic calcium phosphate hydroxyapatitic material intended to be implanted for use in the filling, repair, reconstruction and augmentation of burr holes, contiguous craniotomy cuts, and other defects in craniofacial bones including fronto-orbital, malar and mental areas with a surface area no larger than 25cm².
## PLEASE DO NOT WRITE BELOW THIS LINE--CONTINUE ON ANOTHER PAGE IF NECESSARY
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use
or
Over-the -Counter Use
scally
(Division Sign-Off)
Division of General Restorative Devices
510(k) Number K983009
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.