· Painful, disabling joint disease of the knee resulting from: noninflammatory degenerative joint disease (including osteoarthritis, traumatic arthritis, or avascular necrosis), rheumatoid arthritis or post-traumatic arthritis.

· Post-traumatic loss of knee joint configuration and function.
· Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
· Revision of previous unsuccessful knee replacement or other procedure.
· Fracture of the distal femur and/or proximal tibia that cannot be standard fracture -management techniques.

The Triathlon® Tritanium® Total Knee System components are indicated for both uncemented use.

The Triathlon® Total Knee System beaded and beaded with Peri-Apatite components are intended for uncemented use only.

The Triathlon® All Polyethylene tibial components are indicated for cemented use only.

Additional Indications for Posterior Stabilized (PS) and Total Stabilizer (TS) Components:

· Ligamentous instability requiring implant bearing surface geometries with increased constraint.
· Absent or non-functioning posterior cruciate ligament.
· Severe anteroposterior instability of the knee joint.

Additional Indications for Total Stabilizer (TS) Components:

· Severe instability of the knee secondary to compromised collateral ligament integrity or function.
Indications for Bone Augments:

• Painful, disabling joint disease of the knee secondary to: degenerative arthritis, rheumatoid arthritis, or post-traumatic arthritis, complicated by the presence of bone loss.

· Salvage of previous unsuccessful total knee replacement or other surgical procedure, accompanied by bone loss.
Additional Indications for Cone Augments:
· Severe degeneration or trauma requiring extensive resection and replacement
· Femoral and Tibial bone voids
Metaphyseal reconstruction

The Triathlon TS Cone Augments are intended for cemented or cementless use.

Device Description

The subject Triathlon Intermediate Tibial Inserts will be available in the following configurations:

Cruciate Retaining (CR) intermediate thicknesses of inserts (10mm, 12m, 14mm) will . be added to the previously cleared size range of 9mm, 13mm, 16mm and 19mm
Cruciate Substituting (CS) intermediate thicknesses of inserts (10mm, 12mm and ● 14mm) will be added to the previously cleared size range of 9mm, 11mm, 13mm, 16mm, 19mm, 22mm and 25mm
Posterior Stabilizing (PS) intermediate thicknesses of inserts (10mm. 12mm and . 14mm) will be added to the previously cleared size range of 9mm, 11mm, 13mm, 16mm, 19mm, 22mm and 25mm

The design of these inserts are identical to the predicate devices in terms of condylar geometry. post dimensions (in PS design) and locking wire feature. The inserts will be available in X3 ETO, and N2Vac styles.

Additionally. MR Conditional labeling is being added for the subject intermediate thickness inserts as well as those X3 ETO tibial inserts and patellar components previously cleared in premarket notification K172634.

AI/ML Overview

This document is a 510(k) premarket notification from the FDA for the Triathlon Total Knee System. It is a regulatory approval and not a detailed study report with acceptance criteria and performance metrics typically seen in AI/ML device submissions. Therefore, many of the requested fields cannot be filled.

However, I can extract the information related to the non-clinical testing performed to demonstrate substantial equivalence, which serves as a form of acceptance criteria and evidence of performance for this type of medical device.

Acceptance Criteria and Study for Triathlon Total Knee System (K173849)

This submission is for a Traditional 510(k) for an orthopedic implant (knee replacement system), not an AI/ML diagnostic device. As such, the concept of "acceptance criteria" and "device performance" relies on demonstrating substantial equivalence to already legally marketed devices through material characterization, mechanical testing, and biocompatibility, rather than evaluating diagnostic accuracy or clinical outcomes as would be done for AI/ML.

The "study" here refers to the non-clinical testing conducted to support the substantial equivalence.

1. Table of Acceptance Criteria and Reported Device Performance

For this type of device, "acceptance criteria" are generally compliance with recognized standards and demonstration that new designs do not create a "new worst case" compared to predicate devices. "Reported device performance" is the manufacturer's conclusion that these criteria are met.

Acceptance Criteria (Implied)	Reported Device Performance
Material Properties: Compliance with ASTM F648, ASTM F2565 and FDA Guidance for UHMWPE.	Material characterization previously presented for predicate devices is unchanged and supports substantial equivalence.
Biocompatibility: Compliance with EN ISO 10993-1:2010 and FDA Guidance.	Biocompatibility testing performed for predicate devices is representative.
Sterilization Efficacy: Compliance with EN ISO 11135:2014 for Ethylene Oxide Sterilization Validation.	Ethylene Oxide Sterilization Validation performed for predicate devices is representative.
Wear Resistance: Testing based on ISO/DIS 14243-3:2014.	Wear test performed for predicate devices is representative, as new thicknesses do not create a new worst case.
Static Shear Insert Baseplate Locking Mechanism: Demonstrates integrity of the locking mechanism.	Static Shear Insert Baseplate Locking Mechanism Test performed for predicate devices is representative, as new thicknesses do not create a new worst case.
Fatigue Strength (Single Axis & Multi-Axis): Demonstrates durability under cyclic loading.	Single Axis Fatigue Test and Multi-Axis Fatigue Test performed for predicate devices are representative, as new thicknesses do not create a new worst case.
MR Conditional: Compliance for image artifact, magnetically induced torque/displacement, and RF induced heating per ASTM F2052-15, F2213-06, F2119-07, F2182-11a.	New intermediate thicknesses, as well as previously cleared X3 ETO tibial inserts and patellar components, do not create a new worst case compared to previously cleared Triathlon Total Knee components (K172326). Devices are considered MR Conditional.
Pyrogenicity: Bacterial endotoxin testing (BET) per ANSI/AAMI ST72:2011 to achieve endotoxin limit <20 EU/Device.	Bacterial endotoxin testing performed on subject devices achieved an Endotoxin limit of <20 EU/Device.

2. Sample Size Used for the Test Set and Data Provenance

Test Set Sample Size: Not specified in terms of traditional patient data sample size. The "test set" here refers to physical components and materials subjected to laboratory testing. The document states that the design of the new inserts was analyzed to determine if they created a "new worst case" for material thickness, contact area/stress, moments, and forces. The implication is that specific samples of the new intermediate thicknesses (10mm, 12mm, 14mm) were subjected to various mechanical and material tests, or that the previous test results from predicate devices were deemed representative for these new configurations. The exact number of physical samples tested is not disclosed in this summary.
Data Provenance: Not applicable in the context of human data. The data provenance is from laboratory testing of medical device components and materials. It is neither retrospective nor prospective in the clinical sense.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

Not applicable. "Ground truth" in this context is established through recognized engineering standards, physical measurements, and material science principles, not expert medical opinion on diagnostic images or patient outcomes.

4. Adjudication Method for the Test Set

Not applicable. This concept applies to human-read data (e.g., radiologists reviewing images), not to laboratory testing of physical implants.

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 a knee implant, not an AI/ML diagnostic device with human readers.

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This is a knee implant, not an algorithm.

7. The Type of Ground Truth Used

For Material and Mechanical Testing: The "ground truth" used is defined by internationally recognized standards (ASTM, ISO), FDA guidance, and established engineering principles for material properties, mechanical strength, wear, biocompatibility, and sterilization.
For MR-Conditional Labeling: The ground truth is defined by ASTM standards for measuring magnetic displacement, torque, image artifact, and RF-induced heating.

8. The Sample Size for the Training Set

Not applicable. There is no "training set" in the context of this device approval for an orthopedic implant. The design and manufacturing process are subject to quality systems, but there isn't a machine learning training phase.

9. How the Ground Truth for the Training Set Was Established

Not applicable, as there is no training set.

Summary

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February 2, 2018

Stryker Orthopaedics Margaret Crowe Klippel Sr. Principal Regulatory Affairs Project Manager 325 Corporate Drive Mahwah, New Jersey 07430

Re: K173849

Trade/Device Name: Triathlon Total Knee System Regulation Number: 21 CFR 888.3565 Regulation Name: Knee Joint Patellofemorotibial Metal/Polymer Porous-Coated Uncemented Prosthesis Regulatory Class: Class II Product Code: MBH, JWH Dated: December 18, 2017 Received: December 19, 2017

Dear Margaret Klippel:

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. 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 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); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820);

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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 http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Katherine D. Kavlock -S

for Mark N. Melkerson Director Division of Orthopedic Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K173849

Device Name Triathlon Total Knee System

Indications for Use (Describe)

General Total Knee Arthroplasty (TKR) Indications:

· Post-traumatic loss of knee joint configuration and function.
· Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
· Revision of previous unsuccessful knee replacement or other procedure.
· Fracture of the distal femur and/or proximal tibia that cannot be standard fracture -management techniques.

The Triathlon® Tritanium® Total Knee System components are indicated for both uncemented use.

The Triathlon® Total Knee System beaded and beaded with Peri-Apatite components are intended for uncemented use only.

The Triathlon® All Polyethylene tibial components are indicated for cemented use only.

Additional Indications for Posterior Stabilized (PS) and Total Stabilizer (TS) Components:

· Ligamentous instability requiring implant bearing surface geometries with increased constraint.
· Absent or non-functioning posterior cruciate ligament.
· Severe anteroposterior instability of the knee joint.

Additional Indications for Total Stabilizer (TS) Components:

· Severe instability of the knee secondary to compromised collateral ligament integrity or function.
Indications for Bone Augments:

• Painful, disabling joint disease of the knee secondary to: degenerative arthritis, rheumatoid arthritis, or post-traumatic arthritis, complicated by the presence of bone loss.

· Salvage of previous unsuccessful total knee replacement or other surgical procedure, accompanied by bone loss.
Additional Indications for Cone Augments:
· Severe degeneration or trauma requiring extensive resection and replacement
· Femoral and Tibial bone voids
Metaphyseal reconstruction

The Triathlon TS Cone Augments are intended for cemented or cementless use.

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Type of Use (Select one or both, as applicable)

x | Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

Sponsor	Stryker Orthopaedics325 Corporate DriveMahwah, NJ 07430
Contact Person	Margaret KlippelSenior Principal Regulatory Affairs Project ManagerHowmedica Osteonics Corp325 Corporate DriveMahwah, NJ 07430Phone: (201) 831-5559
Alternate Contact	Kristen MeanySr. Manager, Regulatory AffairsHowmedica Osteonics Corp325 Corporate DriveMahwah, NJ 07430Phone: (201) 972-9164
Date Prepared:	December 15, 2017
Proprietary Name:	Triathlon Total Knee System
Common Name:	Total Knee Joint Replacement
Classification Name:	Knee joint patellofemorotibial metal/polymer porous-coateduncemented prosthesis. (888.3565)Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis (888.3560)

Product Codes: MBH, JWH

Legally Marketed Device to Which Substantial Equivalence is Claimed:

Triathlon X3 ETO Tibial Inserts and Patellar Components K172634 ●
Triathlon CR N2Vac Tibial Inserts K040267, K042883, K051380, K141056, K172326 ●
. Triathlon PS N2Vac Tibial Inserts - K031729, K051380, K141056, K172326
Triathlon CS Total Knee System X3 and N2Vac Tibial Inserts - K063423, K141056, K172326

Device Description:

The subject Triathlon Intermediate Tibial Inserts will be available in the following configurations:

Cruciate Retaining (CR) intermediate thicknesses of inserts (10mm, 12m, 14mm) will . be added to the previously cleared size range of 9mm, 13mm, 16mm and 19mm

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Cruciate Substituting (CS) intermediate thicknesses of inserts (10mm, 12mm and ● 14mm) will be added to the previously cleared size range of 9mm, 11mm, 13mm, 16mm, 19mm, 22mm and 25mm
Posterior Stabilizing (PS) intermediate thicknesses of inserts (10mm. 12mm and . 14mm) will be added to the previously cleared size range of 9mm, 11mm, 13mm, 16mm, 19mm, 22mm and 25mm

Intended Use:

The subject devices have the same intended use as those specified in the 510(k) submissions for the predicate devices listed.

Indications:

General Total Knee Arthroplasty (TKR) Indications:

Painful, disabling joint disease of the knee resulting from: noninflammatory degenerative 0 joint disease (including osteoarthritis, traumatic arthritis, or avascular necrosis), rheumatoid arthritis or post-traumatic arthritis.
Post-traumatic loss of knee joint configuration and function. ●
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
Revision of previous unsuccessful knee replacement or other procedure. ●
Fracture of the distal femur and/or proximal tibia that cannot be stabilized by standard ● fracture -management techniques.

The Triathlon® Tritanium® Total Knee System components are indicated for both uncemented and cemented use.

The Triathlon® Total Knee System beaded and beaded with Peri-Apatite components are intended for uncemented use only.

The Triathlon® All Polyethylene tibial components are indicated for cemented use only.

Additional Indications for Posterior Stabilized (PS) and Total Stabilizer (TS) Components:

. Ligamentous instability requiring implant bearing surface geometries with increased constraint.
Absent or non-functioning posterior cruciate ligament. ●
Severe anteroposterior instability of the knee joint. o

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Additional Indications for Total Stabilizer (TS) Components:

Severe instability of the knee secondary to compromised collateral ligament integrity or function.
Indications for Bone Augments:
Painful, disabling joint disease of the knee secondary to: degenerative arthritis, o rheumatoid arthritis, or post-traumatic arthritis, complicated by the presence of bone loss.
Salvage of previous unsuccessful total knee replacement or other surgical procedure, ● accompanied by bone loss.

Additional Indications for Cone Augments:

Severe degeneration or trauma requiring extensive resection and replacement ●
Femoral and Tibial bone voids ●
Metaphyseal reconstruction

The Triathlon TS Cone Augment components are intended for cemented or cementless use.

Summary of Technological Characteristics:

The subject Triathlon X3 ETO and N2Vac Intermediate Tibial Inserts are identical in intended use, indications, materials, terminal sterilization method and operational principles as the predicate devices. The subject intermediate tibial inserts are different from the predicate device in terms of thicknesses – these intermediate inserts will be available in 10mm, 12mm, and 14mm.

Non-Clinical Testing:

Material characterization of the X3 ETO material and the N2Vac material has been previously presented in premarket notifications for predicate devices. The material properties are unchanged for these predicates - this previous characterization was provided in support of substantial equivalence.

The design of the subject Triathlon intermediate insert thicknesses was analyzed, and it was concluded that these new insert thicknesses do not create a new worst case for minimum or maximum material thickness, contact area/stress, moments and forces required for disassociation. Previous testing performed for the predicate devices is representative of the subject intermediate thicknesses. These tests include:

1. Material Testing per ASTM F648, ASTM F2565, and FDA Guidance, "Characterization of Ultrahigh Molecular Weight Polyethylene (UHMWPE) Used in Orthopedic Devices" (February 12, 2016).
1. Biocompatibility Testing per EN ISO 10993-1:2010 and FDA Guidance, "Use of International Standard ISO 10993-1. "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process" (June 16, 2016)
1. Ethylene Oxide Sterilization Validation per EN ISO 11135:2014

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1. Wear Test based on ISO/DIS 14243-3:2014
1. Static Shear Insert Baseplate Locking Mechanism Test
1. Single Axis Fatigue Test
1. Multi-Axis Fatigue Test

The subject Triathlon intermediate thickness tibial inserts, as well as the Triathlon X3 ETO tibial inserts and patellar components cleared in K172634, were evaluated to determine if these devices created a new worst case for image artifact, magnetically induced torque, magnetically induced displacement, and RF induced heating. These subject devices do not create a new worst case as compared to those Triathlon Total Knee components previously cleared in K172326. The subject devices are considered to be MR Conditional. This analysis reviewed testing performed to the following ASTM standards:

. Magnetically Inducted Displacement Force – performed per ASTM F2052-15, Standard Test Method for Measurement of Magnetically Induced Displacement Force on Medical Devices in the MR Environment
Magnetically Induced Torque - performed per ASTM F2213-06 (Reapproved 2011), Standard Test Method for Measurement of Magnetically Induced Torque on Medical Devices in the MR Environment
Image Artifact performed per ASTM F2119-07 (Reapproved 2013). Standard Test Method ● for Evaluation of MR Image Artifacts from passive Implants
Heating by RF Fields per ASTM F2182-11a, Standard Test Method for Measurement of Radio Frequency Induced Heating near Passive Implants during MR Imaging

Bacterial endotoxin testing (BET) as specified in ANSVAAMI ST72:2011 was used for pyrogenicity testing on the subject devices to achieve an Endotoxin limit of <20 EU/Device.

Clinical Testing: Clinical testing was not required as a basis for substantial equivalence.

Conclusion: The Triathlon® Knee System X3 ETO and N2Vac Tibial Inserts are substantially equivalent to the predicate devices identified in this premarket notification.

Device comparison showed that the proposed device is substantially equivalent in intended use, materials, and performance characteristics to the predicate device. The proposed modifications do not affect safety or effectiveness.

Regulation Number and Section

§ 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

(a)
Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a device intended to be implanted to replace a knee joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra high molecular weight polyethylene tibial bearing is rigidly secured to the metal tibial base plate.(b)
Classification. Class II (special controls). The special control is FDA's guidance: “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA.” See § 888.1 for the availability of this guidance.