The TTC Phantom® Intramedullary Nail system is intended for tibiotalocalcaneal arthrodesis (fusion) and to provide stabilization of the hindfoot and ankle including the transverse tarsal joints coupling the mid-foot to the hindfoot. Examples of specific indications include:

Post-traumatic or degenerative arthritis
Previously infected arthrosis
Revision of failed ankle arthrodesis
Revision of failed total ankle arthroplasty
Talar deficiency conditions such as avascular necrosis of the talus (requiring tibiocalcaneal arthrodesis)
Neuromuscular deformity or other neuromuscular disease with severe deformity or instability of the ankle
Rheumatoid arthritis
Osteoarthritis
Nonunions or pseudarthrosis of hindfoot and distal tibia
Trauma (severe or malunited tibial pilon fracture)
Charcot foot (neuroarthropathy)
Severe end-stage degenerative arthritis
Instability and skeletal defects after tumor resection
Pantalar arthrodesis
Severe foot/ankle deformity

Device Description

The Paragon 28® TTC Phantom® Intramedullary Nail System is comprised of intramedullary nails, screws and accessory components. The TTC Phantom® nails are offered in a variety of sizes and lengths to accommodate variations in patient anatomy. The TTC Phantom® screws insert through the intramedullary nail to secure the construct. These are offered in varying lengths to accommodate the anatomical fixation required.

AI/ML Overview

This is for the approval of a physical medical device (TTC Phantom® Intramedullary Nail System), not a medical AI device. Therefore, much of the requested information (like sample size for test/training sets, data provenance, ground truth establishment, MRMC studies, standalone performance, etc.) is not applicable here as these concepts are specific to the evaluation of AI/ML models.

However, I can provide information based on the provided text regarding the closest equivalent to acceptance criteria and the study performed for this physical device.

Acceptance Criteria and Device Performance (Closest Equivalent for a Physical Device)

Acceptance Criteria (Implied)	Reported Device Performance
Mechanical and Material Equivalence to Predicate Devices	The modified devices demonstrate that the original testing and subsequent performance are not adversely affected by changes in geometry. The analysis and study results indicate the modified designs are substantially equivalent to the predicate devices in performance.
Same Indications for Use as Predicate	The modified TTC Phantom® Intramedullary Nail System possesses the same indications for use as the predicate device.
Same Technological Characteristics as Predicate	The modified devices possess the same technological characteristics as the predicate devices, including performance, basic design, material, manufacturing, and comparable dimensions.

Study Information (Based on Physical Device Evaluation):

Sample size used for the test set and the data provenance: Not applicable in the context of AI/ML model evaluation. For this physical device, the "test set" would refer to the components undergoing engineering analysis and cadaveric implantation. The text does not specify the number of components or cadavers used, nor their specific provenance.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth for a physical device like an intramedullary nail is established through engineering principles, material testing standards, and mechanical performance evaluation rather than subjective expert consensus on data interpretation.
Adjudication method for the test set: Not applicable for a physical device evaluation. Adjudication methods are typically employed in studies where multiple human readers interpret data that may have ambiguous findings, which is not the case for material and mechanical performance testing.
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 for a physical medical device, not an AI product.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is for a physical medical device.
The type of ground truth used:
- Engineering analysis: This implies adherence to established engineering principles and standards for material strength, durability, and biomechanical function.
- Cadaveric implantation study: This provides practical, real-world (though ex-vivo) evidence of how the device performs within a biological context, assessing fit, stability, and potential issues during implantation.
- The "ground truth" here is the objective measurement of mechanical properties and functional performance against established benchmarks and predicate device performance.
The sample size for the training set: Not applicable. This is for a physical medical device. The "training" for such a device involves design iterations, material selection, and manufacturing process optimization, not algorithm training data.
How the ground truth for the training set was established: Not applicable. For a physical device, continuous improvement and design validation are ongoing processes. The basis for design decisions and material choices would come from established engineering and medical device standards, previous product performance, and clinical needs.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which consists of the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG" in blue, with the word "ADMINISTRATION" underneath in a smaller font.

September 6, 2019

Paragon 28, Inc. Eric Lintula Director of Regulatory Affairs 4B Inverness Ct. E., STE 280 Englewood, Colorado 80112

Re: K191782

Trade/Device Name: TTC Phantom Intramedullary Nail System Regulation Number: 21 CFR 888.3020 Regulation Name: Intramedullary Fixation Rod Regulatory Class: Class II Product Code: HSB, HWC Dated: August 15, 2019 Received: August 15, 2019

Dear Eric Lintula:

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 statutes and regulations administered by other Federal agencies. You must comply with all the Act's

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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 (OS) 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 mediation-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,

For Michael C. Owens Acting 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

Form Approved: OMB No. 0910-0120 Expiration Date: 06/30/2020 See PRA Statement below.

510(k) Number (if known) K191782

Device Name

TTC Phantom® Intramedullary Nail System

Indications for Use (Describe)

Post-traumatic or degenerative arthritis
· Previously infected arthrosis
Revision of failed ankle arthrodesis
· Revision of failed total ankle arthroplasty
· Talar deficiency conditions such as avascular necrosis of the talus (requiring tibiocalcaneal arthrodesis)
· Neuromuscular deformity or other neuromuscular disease with severe deformity or instability of the ankle
Rheumatoid arthritis
· Osteoarthritis
Nonunions or pseudarthrosis of hindfoot and distal tibia
· Trauma (severe or malunited tibial pilon fracture)
· Charcot foot (neuroarthropathy)
· Severe end-stage degenerative arthritis
Instability and skeletal defects after tumor resection
· Pantalar arthrodesis
· Severe foot/ankle deformity

Type of Use (Select one or both, as applicable)
☑ Prescription Use (Part 21 CFR 801 Subpart D)	☐ Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

510(k) Number:	K191782
Date:	July 1st, 2019
Sponsor:	Paragon 28, Inc.14445 Grasslands Dr.Englewood, Colorado 80112Phone: (855) 786-2828Fax: (888) 728-1220
Sponsor contact:	Eric Lintula, Director of Regulatory Affairs
Trade Name:	TTC Phantom® Intramedullary Nail System
Regulatory Class:	Class II
Regulation,Product Code,Classification, andCommon Name:	888.3020, HSB, Rod, Fixation, Intramedullary And Accessories888.3040, HWC, Screw, Fixation, Bone
DeviceDescription:	The Paragon 28® TTC Phantom® Intramedullary Nail Systemis comprised of intramedullary nails, screws and accessorycomponents. The TTC Phantom® nails are offered in a varietyof sizes and lengths to accommodate variations in patientanatomy. The TTC Phantom® screws insert through theintramedullary nail to secure the construct. These are offered invarying lengths to accommodate the anatomical fixationrequired.
Materials:	The TTC Phantom® Intramedullary Nail System implants aremade from Titanium Alloy (ASTM F136). The instrumentationis manufactured from medical grades of titanium alloy, stainlesssteel, anodized aluminum and polymer.
Indications forUse:	The TTC Phantom® Intramedullary Nail system is intended fortibiotalocalcaneal arthrodesis (fusion) and to providestabilization of the hindfoot and ankle including the transversetarsal joints coupling the mid-foot to the hindfoot. Examples ofspecific indications include:● Post-traumatic or degenerative arthritis● Previously infected arthrosis● Revision of failed ankle arthrodesis● Revision of failed total ankle arthroplasty● Talar deficiency conditions such as avascular necrosis ofthe talus (requiring tibiocalcaneal arthrodesis)● Neuromuscular deformity or other neuromusculardisease with severe deformity or instability of the ankle● Rheumatoid arthritis● Osteoarthritis● Nonunions or pseudarthrosis of hindfoot and distal tibia
	Charcot foot (neuroarthropathy) Severe end-stage degenerative arthritis Instability and skeletal defects after tumor resection Pantalar arthrodesis Severe foot/ankle deformity
PrimaryPredicate:	K182307, TTC Phantom® Intramedullary Nail System
	K102413, Vilex FUZE TTC Arthrodesis Compression Nail
	K040212, Smith & Nephew TRIGEN INTERTAN
Reference Devices:	Intertrochanteric Antegrde Nails
	K190365, Paragon 28 Baby Gorilla®/Gorilla® Plating System
	K120419, Lavender Medical Dyna Locking Ankle (DLA) Nail
PerformanceData:	Engineering analysis and a cadaveric implantation study arepresented to provide evidence that the original testing andsubsequent performance is not adversely affected by thegeometry of the modified devices.The results of the analysis and study demonstrate the modifieddesigns are substantially equivalent to the predicate devices.
TechnologicalCharacteristics:	The modified devices possess the same technologicalcharacteristics as the predicate devices. These include;
	Performance, Basic design, Material, Manufacturing, and Sizes (dimensions are comparable to those offered by thepredicate systems). Therefore, the fundamental scientific technology of the modifieddevices is similar to the previously cleared devices.
Conclusion:	The modified TTC Phantom® Intramedullary Nail Systempossesses the same indications for use and technologicalcharacteristics as the predicate device. Therefore, the modifieddevices are substantially equivalent to the predicate.

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Regulation Number and Section

§ 888.3020 Intramedullary fixation rod.

(a)
Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures.(b)
Classification. Class II.