The Axiom PSR System is intended to be used as patient specific surgical planning and instrumentation to assist in the positioning of total ankle replacement components intraoperatively, and in guiding bone cutting. The Axiom PSR System is intended for use with the Kinos Axiom Total Ankle System and its cleared indications for use.
Device Story
Axiom PSR System provides patient-specific surgical planning and instrumentation for total ankle replacement. Input: patient CT scans. Process: surgeon-approved preoperative planning; CAD-based digital workflow; 3D printing of patient-specific titanium resection guides and biocompatible polymer bone models. Output: physical guides used intraoperatively by orthopedic surgeons to assist in bone cutting and positioning of Kinos Axiom Total Ankle System components. Benefit: improved accuracy of implant placement relative to preoperative plans compared to standard instrumentation; facilitates personalized surgical approach.
Clinical Evidence
Non-clinical cadaveric study conducted. Primary endpoint: accuracy of implant placement in 3D space (6 degrees of freedom) compared to preoperative plans. Results: Axiom PSR System demonstrated accuracy at least as good as or better than standard Kinos Axiom instrumentation. Process qualification confirmed output specifications. Biocompatibility, cleaning, sterilization, and shelf-life validated via established protocols.
Technological Characteristics
Patient-specific resection guides (Ti-6Al-4V titanium alloy) and bone models (biocompatible polymer). 3D printing manufacturing. Digital workflow involves CT image transformation and CAD manipulation. Standalone system used with standard surgical instruments. Sterilization and biocompatibility validated per established company standards.
Indications for Use
Indicated for patients undergoing total ankle replacement requiring patient-specific surgical planning and instrumentation to assist in component positioning and bone resection, used in conjunction with the Kinos Axiom Total Ankle System.
Regulatory Classification
Identification
An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces and has no linkage across-the-joint. This generic type of device includes prostheses that have a talar resurfacing component made of alloys, such as cobalt-chromium-molybdenum, and a tibial resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).
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March 30, 2023
restor3d, inc. Brianna Prindle Head of Regulatory 311 W. Corporation St. Durham, North Carolina 27701
Re: K223326
Trade/Device Name: Axiom PSR System Regulation Number: 21 CFR 888.3110 Regulation Name: Ankle Joint Metal/Polymer Semi-Constrained Cemented Prosthesis Regulatory Class: Class II Product Code: OYK Dated: February 24, 2023 Received: February 24, 2023
Dear Brianna Prindle:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal
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statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
# Limin Sun -S
Limin Sun, Ph.D. Assistant Director DHT6A: Division of Joint Arthroplasty Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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## Indications for Use
510(k) Number (if known) K223326
Device Name Axiom PSR System
#### Indications for Use (Describe)
The Axiom PSR System is intended to be used as patient specific surgical planning and instrumentation to assist in the positioning of total ankle replacement components intraoperatively, and in guiding bone cutting. The Axiom PSR System is intended for use with the Kinos Axiom Total Ankle System and its cleared indications for use.
Type of Use (Select one or both, as applicable)
| <div> <span> <span style="font-size: 16px;">☑</span> Prescription Use (Part 21 CFR 801 Subpart D) </span> </div> |
|----------------------------------------------------------------------------------------------------------------------|
| <div> <span> <span style="font-size: 16px;">☐</span> Over-The-Counter Use (21 CFR 801 Subpart C) </span> </div> |
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K223326 page 1 of 3
Image /page/3/Picture/1 description: The image shows the word "restor3d" in a bold, sans-serif font. The first six letters, "restor", are solid black. The last two characters, "3d", are outlined in black, with a white fill.
311 W. Corporation St. Durham, NC 27701 984.888.0593
#### 510(k) Summary
#### 510(k) Number: K223326
This 510(k) summary is being submitted in accordance with the requirements of 21 CFR 807.92.
#### A. 510(k) Owner:
restor3d, inc. 311 W. Corporation St. Durham, NC 27701
#### B. Primary Correspondent:
Brianna Prindle Head of Regulatory brianna@restor3d.com
#### C. Premarket Notification:
| Submission Type: | Traditional 510(k) |
|----------------------|-------------------------------------------------------------------|
| Trade Name: | Axiom PSR System |
| Classification: | Class II |
| Product Code: | OYK |
| Classification Name: | Ankle Arthroplasty Implantation System |
| Regulation Number: | 21 CFR 888.3110 |
| Regulation Name: | Ankle joint metal/polymer semi-constrained cemented<br>prosthesis |
#### D. Indications for Use:
The Axiom PSR System is intended to be used as patient specific surgical planning and instrumentation to assist in the positioning of total ankle replacement components intraoperatively, and in guiding bone cutting. The Axiom PSR System is intended for use with the Kinos Axiom Total Ankle System and its cleared indications for use.
#### E. Predicate Devices:
Kinos Axiom PSR is substantially equivalent to the following devices:
| 510(k) | Trade Name | Manufacturer |
|-----------------------------|--------------------|--------------------------------------------|
| Primary Predicate Device | | |
| K193432 | Vantage PSI System | Medical Modeling – A 3D<br>Systems Company |
| Secondary Predicate Devices | | |
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311 W. Corporation St. Durham, NC 27701 984.888.0593
| 510(k) | Trade Name | Manufacturer |
|---------|-----------------------------------------|--------------|
| K192778 | Kinos Axiom Total Ankle System | restor3d |
| K220523 | Tidal Lumbar Interbody Fusion<br>Device | restor3d |
### F. Device Description:
restor3d's Axiom PSR System is an ankle surgical guide system, designed for an individual patient from the patient's CT imaging scans. The subject Axiom PSR System is intended to aid in the placement of Kinos Axiom Total Ankle System (K192778) implant components when used in conjunction with the Kinos Axiom standard, reusable instruments. The Axiom PSR System includes preoperative plans developed with and approved by the operative surgeon, tibia and talus resection guides, manufactured from implant grade titanium, bone models manufactured from biocompatible polymer for use with the Kinos Axiom Total Ankle System.
### G. Comparison of Technological Characteristics
The intended use and technological characteristics of the subject Axiom PSR System are either identical or substantially equivalent to the predicate device (Vantage PSI System, K193432).
The principles of operation and technological characteristics are substantially equivalent between the Axiom PSR System and the identified predicate. Specifically, the predicate device includes pre-operative planning from patient CT imaging scans, 3D printing of patient specific bone models and resection guides. Both the subject and predicate system perform bone resection cuts directly through the patient specific guides and are used to aid in the placement of a previously cleared total ankle system when used in conjunction with standard instruments of their respective total ankle system.
The subject Axiom PSR System uses the same fundamental technologies employed in the digital workflow as the predicate device, including medical image transformation and manipulation in a CAD environment with digital outputs subsequently used for 3D printing of the patient specific devices.
The subject Axiom PSR System resection guides and bone models are made from implant grade titanium alloy (Ti-6Al-4V) and biocompatible polymer. Whereas the predicate device resection guides are made from polyamide. The biocompatibility of the subject Axiom PSR System resection guides and bone models has been assessed through testing in support of this and other 510(k) submissions and does not represent any new or increased risks with respect to technological characteristics.
### H. Summary of Performance Testing
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Image /page/5/Picture/1 description: The image shows the word "restor3d" in a bold, sans-serif font. The first six letters, "restor," are solid black, while the "3d" is outlined in black. The letters are closely spaced, creating a compact and modern look.
311 W. Corporation St. Durham, NC 27701 984.888.0593
Non-clinical, cadaver testing was conducted to validate the digital design workflow and assess the accuracy of the subject Axiom PSR System, compared to the previously cleared Kinos Axiom Total Ankle System. Post-operative CT scans were obtained, and the final implant positions were evaluated in 3D space about six degrees of freedom and then compared to the pre-operative plans. Cadaver validation testing demonstrated that the subject Axiom PSR System was at least as accurate or more accurate than using the previously cleared Kinos Axiom Total Ankle System standard instruments alone, with respect to implant placement relative to the preoperative plan in six degrees of freedom.
Process qualification was performed to demonstrate manufactured devices meet the output specifications of the digital design workflow.
Cleaning, biocompatibility, sterilization, and shelf life were evaluated against previously conducted validations. The evaluations demonstrate acceptable adoption into previously established manufacturing processes, materials and specifications employed in restor3d's previously cleared implant and instrument systems, including the restor3d Tidal Lumbar Interbody Fusion Device (K220523), therefore the subject device does not represent any new or increased concerns of safety or efficacy.
#### l. Conclusions:
Based on comparison of the intended use, indications for use and technological characteristics, the subject Axiom PSR System is substantially equivalent to the predicate Vantage PSI System. Minor differences in the material and technological considerations do not raise any new or different questions of safety or effectiveness. Additionally, the cadaveric testing demonstrates the system performs in accordance with its intended use and is as safe, effective and performs as well as the previously cleared Kinos Axiom Total Ankle System (K192778) predicate device.
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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.
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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?
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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.
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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.
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Reading rule for every project: how many summaries do you read in full?
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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.
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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.
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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.
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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.