The GMK knee prosthesis is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components.

This knee replacement system is indicated in the following cases:

· Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis.

· Avascular necrosis of femoral condyle.
Post traumatic loss of joint configuration.
· Primary implantation failure.

Tibial augments are to be attached to the tibial baseplate with both the fixing cylinders and bone cement.

In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components.

Device Description

The GMK Narrow Femoral Components are intermediate sizes within the 510(k) cleared size range of the K090988 GMK Total Knee System. GMK Narrow components are designed with the same AP dimension as the correspondent K090988 GMK Total Knee System components (from Size 2 to Size 6) but with a reduced ML dimension of 4 mm. The reduced ML dimension of 4mm corresponds to an "X-1" size of the K090988 GMK Femur in the ML plane. The articular surfaces profile remains the same as the existing femoral components, both for the condyles and the trochlear groove. GMK Narrow Femoral Components are provided in the STD cemented version (to be used with STD and UC fixed tibial inserts) and in the PS cemented version (to be used with PS fixed tibial inserts).

AI/ML Overview

The provided document is a 510(k) summary for the Medacta GMK Narrow Total Knee Prosthesis, which sought to demonstrate substantial equivalence to previously cleared predicate devices. The study conducted to support this submission was a performance testing using finite element method (FEM) analysis.

Here's the breakdown of the information requested:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance
GMK Narrow Femoral Components do not represent worst-case conditions compared to the predicate devices in terms of stress distribution, Range of Motion (ROM), constraints, mobility, and wear behavior.	FEM analysis determined that the GMK Narrow femoral components are not worst-case in comparison to the worst-case K090988 GMK Total Knee components with respect to stress distribution, ROM, constraints, mobility, and wear behavior.

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

Sample Size for Test Set: The document does not specify a numerical sample size in the traditional sense of a clinical trial or physical testing with a number of units. Instead, it refers to evaluating the "GMK Narrow Femoral Components" through FEM analysis. This implies the analysis covered the designs of the GMK Narrow components across their intended sizes and configurations.
Data Provenance: Not applicable in the context of FEM analysis. The data for FEM analysis would be generated internally from the design specifications and material properties of the device and its predicate, rather than from human subjects or existing clinical datasets.

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

Number of Experts: Not explicitly stated as this was a computational analysis (FEM). Engineering experts, likely with expertise in biomechanics, materials science, and finite element modeling, would have been involved in setting up the simulations and interpreting the results.
Qualifications of Experts: Not specified.

4. Adjudication Method for the Test Set

Adjudication Method: Not applicable. The "test set" here refers to the FEM analysis, which generates quantitative data based on engineering principles and computational models. There is no human adjudication of results in this context, but rather an engineering review and comparison to specific criteria.

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

MRMC Study: No, this was not a multi-reader multi-case comparative effectiveness study. This study involved finite element method (FEM) analysis of a medical device (knee prosthesis), not AI assistance for human readers or interpretation of medical images.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Standalone Performance: Yes, in a manner of speaking within the context of engineering analysis. The FEM analysis is a computational model of the device performance, operating independently of human intervention during the simulation itself. The results of the simulation are then interpreted by engineers. This is a "device-only" performance assessment based on physical principles, not an "algorithm-only" performance in the context of AI.

7. The Type of Ground Truth Used

Type of Ground Truth: The "ground truth" for this FEM analysis was derived from established engineering principles, material properties (e.g., Cobalt Chromium Molybdenum according to ISO5832-4:1996), and the known performance characteristics of the predicate devices. The goal was to compare the newly designed component's performance (stress distribution, ROM, constraints, mobility, wear behavior) against the established safe performance of the predicate device.

8. The Sample Size for the Training Set

Sample Size for Training Set: Not applicable. FEM analysis does not involve a "training set" in the machine learning sense. The models are built based on physical geometry, material properties, and boundary conditions.

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

Ground Truth for Training Set Establishment: Not applicable. As there is no training set, there is no ground truth established for one. The "truth" in FEM comes from the physical laws and material behaviors programmed into the model and validated against known real-world behaviors and predicate device performance.

Summary

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K122232(113)

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SEP
2 8 2012

510(k) Summary

Applicant/Sponsor: Medacta International SA Strada Regina 6874 Castel San Pietro (CH) Switzerland Phone (+41) 91 696 60 60 Fax (+41) 91 696 60 66

Contact Person: Mr. Adam Gross Director of Regulatory and Quality Medacta USA 4725 Calle Quetzal, Unit B Camarillo, CA, 93012 Phone: (805)437-7085 Fax: (805)437-7553 Email: AGross@medacta.us.com

Date Prepared: July 20, 2012

DEVICE INFORMATION

Trade/Proprietary Name: GMK Narrow Common Name: Total Knee Prosthesis Classification Name: Knee joint patellofemorotibial polymer/metal/polymer semiconstrained cemented prosthesis

21 CFR 888.3560 Class II Device Product Codes: JWH

Predicate Devices:

K090988 GMK Total Knee System (Medacta International) K120790 GMK - Line Extension (Medacta International)

GMK Narrow 510(k)

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Product Description

Indications for Use

The GMK knee prosthesis is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components.

This knee replacement system is indicated in the following cases:

· Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polvarthritis.

· Avascular necrosis of femoral condyle.
Post traumatic loss of joint configuration.
· Primary implantation failure.

Tibial augments are to be attached to the tibial baseplate with both the fixing cylinders and bone cement.

In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components.

Comparison to Predicate Devices

The indications for use of the GMK Narrow are identical to K120790 GMK - Line Extension. The design features and materials of the subject devices are substantially equivalent to those of the predicate devices. In terms of design features, GMK Narrow components are designed with the same AP dimension as the correspondent K090988 GMK Total Knee System femoral components (from Size 2 to Size 6) but with a reduced ML dimension of 4 mm. The reduced ML dimension of 4mm corresponds to an "X-1" size of the K090988 GMK Femur in the ML plane. The articular surfaces profile remains the same as the existing femoral components, both for the condyles and the trochlear groove. In terms of materials, GMK Narrow components are made from Cobalt Chromium Molybdenum (CoCrMo) according to ISO5832-4:1996, Implants for Surgery -

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Metallic materials - Part 4: Cobalt-chromium-molybdenum Casting Alloy which is the same as the predicate devices. The fundamental scientific technology of the modified devices has not changed relative to the predicate devices. The safety and effectiveness of the GMK Narrow are adequately supported by the substantial equivalence information, materials information, and analysis data provided within this Premarket Notification.

Performance Testing

GMK Narrow was evaluated using finite element method (FEM) analysis to demonstrate that the GMK Narrow Femoral Components do not represent worst case conditions compared to the predicate devices and that no further mechanical tests are necessary.

The modification to the device system to include the addition of the GMK Narrow was evaluated by risk analysis to identify any new risks associated with the change. Based on the risk analysis, design verification was conducted to written protocols with predefined acceptance criteria. The protocols and pre-defined acceptance criteria were based on the standards, FDA guidance, and comparison to the predicate device system. The testing was compared to the worst case component size and option/design based on engineering analysis. The GMK Narrow was compared to the worst case K090988 GMK Total Knee components in terms of stress distribution, ROM, constraints, mobility and wear behavior and it was determined that the GMK Narrow femoral components are not worst case.

Conclusion:

Based on the above information, the GMK Narrow can be considered as substantially equivalent to its predicate devices.

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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" around the perimeter. Inside the circle is a stylized symbol that resembles a human figure embracing a globe or sphere.

Public Health Service

Food and Drug Administration 10903 New Hampshire Avenue Document Control Room -WO66-G609 Silver Spring, MD 20993-0002

Medacta International % Medacta USA Mr. Adam Gross Director of Regulatory and Quality 4725 Calle Quetzal, Unit B Camarillo, California 93012

Received: August 29, 2012

Re: K122232

Trade/Device Name: GMK Narrow Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis Regulatory Class: Class II Product Code: JWH Dated: August 28, 2012

Dear Mr. Gross:

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.

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 (reporting of medical

EP 28 2012

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Page 2 - Mr. Adam Gross

device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely yours,
Mark M. Milliken

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

Enclosure

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K12232 (111)

Indications for Use

510(k) Number (if known):

Device Name: GMK Narrow

Indications for Use:

The GMK knee prosthesis is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components.

This knee replacement system is indicated in the following cases:

· Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis.

· Avascular necrosis of femoral condyle.
Post traumatic loss of joint configuration.
· Primary implantation failure.

Tibial augments are to be attached to the tibial baseplate with both the fixing cylinders and bone cement.

In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components.

Prescription Use X (21 CFR 801 Subpart D)

AND/OR

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

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)

(Division Sign-Off)
Division of Surgical, Orthopedic, and Restorative Devices

GMK Narrow 510(k)
July 24, 2012
510(k) Number	K122232
	Section 4 - Page 2 of 2

Regulation Number and Section

§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.