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 Sphere Total Knee System allows for medial-pivot rotation of the knee joint and is comprised of the following components: - Femoral Component Left and Right, Sizes 1-7 Co-Cr-Mo (ISO 5832-4) - Tibial tray fixed cemented Left and Right, 4 intermediate sizes . Co-Cr-Mo (ISO 5832-4) - Tibial Insert Fixed Flex and Congruent, Left and Right, Sizes 1-6, 10mm-20mm . UHMWPE (ISO 5834 -2) Type 1, Ti6Al4V (ISO 5232-3)

AI/ML Overview

The provided text does not contain detailed information about specific acceptance criteria with numerical thresholds, nor does it describe a study where a medical device's performance is measured against such criteria.

Instead, the document is a 510(k) summary for the GMK Sphere Total Knee System, which focuses on demonstrating substantial equivalence to predicate devices. This type of submission relies on showing that the new device has the same intended use and technological characteristics as a legally marketed predicate device, or that any differences do not raise new questions of safety or effectiveness.

Here's a breakdown of what the document does provide in relation to performance and equivalence:

1. Acceptance Criteria and Reported Device Performance (as inferred from the substantial equivalence claim):

The document states that "A review of the mechanical data indicates that the GMK Sphere is equivalent to devices currently cleared for use and is capable of withstanding expected in vivo loading without failure." This implies that the acceptance criteria are essentially equivalence to predicate devices in terms of mechanical performance and the ability to withstand physiological loads without failure.

Acceptance Criteria (Inferred from Equivalence)	Reported Device Performance
Instability due to design and surface area	Equivalent to cleared predicate devices
Constraint measurements	Equivalent to cleared predicate devices
Contact pressures and areas	Equivalent to cleared predicate devices
Dynamic physiological loads	Capable of withstanding expected in vivo loading without failure (equivalent to predicates)
Modular connection	Equivalent to cleared predicate devices
Range of Motion (ASTM 2083)	Equivalent to cleared predicate devices

2. Sample size used for the test set and the data provenance:

Sample Size: Not specified. The document mentions "mechanical data" but does not detail the number of samples or specific tests performed, or the number of simulated uses, etc..
Data Provenance: Not specified. It's likely laboratory testing.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

This information is not applicable and not provided. The testing described is mechanical, not involving human interpretation of data for ground truth establishment.

4. Adjudication method for the test set:

Not applicable, as it's mechanical testing.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:

No, an MRMC study was not done. This type of study is typically for evaluating diagnostic devices where reader performance is a key factor. This document is for a Class II knee prosthesis.

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

Not applicable. This device is a physical implant, not an algorithm.

7. The type of ground truth used:

For mechanical testing of implants, the "ground truth" is typically defined by engineering standards (e.g., ASTM standards for range of motion, fatigue life, strength) and the performance characteristics of predicate devices that have been deemed safe and effective.

8. The sample size for the training set:

Not applicable. This is not a machine learning device that requires a training set.

9. How the ground truth for the training set was established:

Not applicable.

In summary:

The provided text describes a 510(k) submission for a knee prosthesis, which focuses on demonstrating substantial equivalence to previously cleared devices through mechanical performance testing. It does not describe a study that uses acceptance criteria with specific numerical thresholds met by the device's performance in a way that would be typical for, for example, an AI/ML-driven diagnostic device. The "acceptance criteria" here are implicitly linked to the performance of the legally marketed predicate devices, and the "study" is the mechanical testing conducted and reviewed to support the equivalence claim.

Summary

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K121416-113

JUL 30 2012

Image /page/0/Picture/2 description: The image shows the logo for Medacta International. The logo consists of two black triangles, the word "Medacta" in black, and the word "International" in black. There is a plus sign to the right of the word "International".

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

Mr. Adam Gross Contact Person: 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: 05/11/2012

DEVICE INFORMATION

Trade/Proprietary Name: GMK Sphere 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

GMK Sphere 510(k)

Section 5 - Page 2 of 4

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Predicate Devices:

510(k)	Product	510(k) Holder
K090988	GMK Total Knee System	Medacta International
K972626	Advance Knee System	Wright Medical Technology
K972770	Advance UC Tibial Insert	Wright Medical Technology
K974328	Advance Total Knee System	Wright Medical Technology
K991052	FS 1000 Knee System	Renaissance Instruments, LLC
K081023	Evolis Total Knee System	Medacta International
K102437	GMK Total Knee System- Revision	Medacta International
K103170	GMK Revision SC Liners	Medacta International
K113571	GMK Resurfacing Patella Size 4	Medacta International

Product Description

The GMK Sphere Total Knee System allows for medial-pivot rotation of the knee joint and is comprised of the following components:

Femoral Component Left and Right, Sizes 1-7 � Co-Cr-Mo (ISO 5832-4)
Tibial tray fixed cemented Left and Right, 4 intermediate sizes . Co-Cr-Mo (ISO 5832-4)
Tibial Insert Fixed Flex and Congruent, Left and Right, Sizes 1-6, 10mm-20mm . UHMWPE (ISO 5834 -2) Type 1, Ti6Al4V (ISO 5232-3)

The following components of the GMK Sphere have been previously cleared:

Resurfacing patella Sizes 1-4 (K090988 and K113571) .
Tibial tray fixed cemented Left and Right, Sizes 1-6 (K090988) .
Primary extension stem Ø11mm / L 65 mm (K090988) .

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.

GMK Sphere 510(k)

Section 5 - Page 3 of 4

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K121416 (³/₃)

Comparison to Predicate Devices

The indications for use of the GMK Sphere are identical to the previously cleared predicate devices. The design features and materials of the subject devices are substantially equivalent to those of 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 Sphere are adequately supported by the substantial equivalence information, materials information, and analysis data provided within this Premarket Notification.

Performance Testing

The GMK Sphere was tested for the following compared to the predicate devices:

Instability due to design and surface area .
Constraint measurements .
Contact pressures and areas .
Dynamic physiological loads .
Modular connection .
Range of Motion ASTM 2083 .

A review of the mechanical data indicates that the GMK Sphere is equivalent to devices . currently cleared for use and is capable of withstanding expected in vivo foading without failure.

Conclusion:

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

Section 5 - Page 4 of 4

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Image /page/3/Picture/1 description: The image shows the seal of the Department of Health & Human Services - USA. The seal features a stylized eagle with three lines forming its body and wings. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle.

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

JUL 30 2012

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

Re: K121416

Trade/Device Name: GMK Sphere 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: May 11, 2012 Received: May 11, 2012

Dear Mr. Gross

We have reviewed your Section 510(k) premarket notification of intent to market the device w & now and have 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 I ou may, dicrore, mains of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adviteration. 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.

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Page 2 - Mr. Adam Gross

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 device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) 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 N. Malkerson

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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Indications for Use

510(k) Number (if known): K | 2 | 4 | 0

Device Name: GMK Sphere

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.

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

510(k) Number K 121416

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)

GMK Sphere 510(k) May 10, 2012

Section 4 - Page 2 of 2

Kizlanb (VI

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.