The LINK® Endo-Model® Knee System is indicated for patients with severe joint diseases with limitation of mobility due to degenerative, rheumatoid or post-traumatic arthrosis or arthritis. Joint fractures which disallow an osteosynthetic reconstruction. This device is intended for cemented use only unless a cementless modular stem is indicated for use.

The LINK® Endo-Model® Rotating Hinge and Modular Rotating Hinge Knee System are indicated for the following conditions:

Bone necroses.
Bicondylar arthrosis by partly damaged collateral ligaments
Revision after primary total knee replacement.
Revision surgery after hinge knee or rotational knee joint.
Revision surgery by insufficient / inadequate bone mass.
Arthrosis of patella flange.
Valgus/Varus deformities <10°.
Valgus/Varus deformities 10-15°.
Valgus/Varus deformities 15-20°.

The LINK® Endo-Model® Non-Rotating Hinge and Modular Non-Rotating Hinge Knee System are indicated for the following conditions:

Bone necroses.
Bicondylar arthrosis by completely damaged ligaments and muscular instability.
Revision after primary total knee replacement.
Revision surgery after hinge knee or rotational knee joint.
Revision surgery by insufficient / inadequate bone mass.
Arthrosis of patella flange.
Valgus/Varus deformities <10°.
Valgus/Varus deformities 10-15°.
Valgus/Varus deformities 15-20°.
Valgus/Varus deformities 20-30°.

Device Description

The LINK® Endo-Model® Knee System is constrained anti-luxation total knee prosthesis. Retaining the low friction principle, the physiological movement of the rotational knee prosthesis is optimal because the pivot point is within the physiological area. Flexion and rotation of the rotational knee prosthesis take place in a cross joint. The LINK® Endo-Model® Knee System consists of Femoral and Tibial Components, Modular Stems, Femoral Segments and Proximal Tibial Spacers and Segments. The modular components are interchangeable allowing for independent positioning. The Modular Stems are available in a variety of diameters and lengths in cemented or cementless version. Special Femoral Segments for revision surgery of resurfacing knee implants and for tumor cases are available in a variety of heights. Proximal Tibial Spacers and Segments are used to act as a spacer for the missing bone where surgical reasons require the removal bone.

The LINK® Endo-Model® Knee System is available in four (4) different knee joint versions:

Rotating Hinge Knee Standard (Non-Modular) -Version
Non-Rotating Hinge Knee Standard (Non-Modular) -Version
Rotating Hinge Knee Modular Version -
Non-Rotating Hinge Knee Modular Version -

There are two (2) different versions in the application of the knee system: Rotating and Non-Rotating Hinge version. The main design differences between the Rotating and Non-Rotating Hinge version are the two (2) different mechanical connections between the femoral and the tibial component and the consequent movement of these components. These two (2) different connections are necessary because of the different biophysical properties of the human body and the different indications and contraindications for the use of these products.

The LINK® Endo-Model® Knee System is produced of Cobalt Chromium Molybdenum casting alloy (CoCrMo) and Ultra high molecular weight polyethylene (UHMWPE / noncrosslinked). The Modular Stems (cemented) are made of Cobalt Chromium Molybdenum casting alloy (CoCrMo) materials. The Modular Stems (cementless) are made of Titanium-Aluminum-Vanadium alloy (Ti-6A1-4V) materials. Femoral Segments, Proximal Tibial Spacers and Segments are produced of Titanium-Aluminum-Vanadium alloy (Ti-6A1-4V). There are also Proximal Tibial Spacers which were made of Ultra high molecular weight polyethylene (UHMWPE / non-crosslinked). Centralizers and Patella components are made of Ultra high molecular weight polyethylene (UHMWPE / non-crosslinked). All components are sterile and for single use only.

AI/ML Overview

The provided document is a 510(k) premarket notification for a medical device (The LINK® Endo-Model® Knee System, K143179). It focuses on demonstrating substantial equivalence to a legally marketed predicate device rather than presenting a study to prove acceptance criteria for an AI device.

Therefore, most of the requested information regarding AI device performance, sample sizes, ground truth establishment, expert adjudication, or MRMC studies for an AI system is not applicable and not present in this document.

However, I can extract information related to the device's technical specifications and the non-clinical performance testing used to demonstrate its safety and effectiveness, which serves as a form of "acceptance criteria" for this type of medical device in the context of a 510(k) submission.

Here's the closest interpretation of the requested information based on the provided text:

Acceptance Criteria and Study for The LINK® Endo-Model® Knee System

The provided document describes a premarket notification (510(k)) for a knee replacement system, not an AI device. Therefore, the questions regarding AI-specific criteria (like AI performance, ground truth, expert opinions, MRMC studies) are not applicable.

The "acceptance criteria" for a medical device like this, in the context of a 510(k), are typically based on demonstrating substantial equivalence to a predicate device through engineering and performance testing (non-clinical studies), and adherence to relevant standards.

Here's a breakdown of the available information:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Non-Clinical)	Reported Device Performance
Mechanical Integrity/Durability:
Tibial Bearing Component wear tests per ISO 14243-1 and -2	Not explicitly detailed, but implied to meet standards.
Tibial Baseplate Component fatigue tests per ISO 14879 and ASTM F1800	All test samples completed 10 million cycles without evidence of fracture or cracking.
Modular Connections, Fretting, and Corrosion Testing per ASTM F1875-98	Not explicitly detailed, but implied to meet standards.
Tibiafemoral and Patellofemoral contact area / stress analyses at different angles of flexion	Not explicitly detailed, but implied to meet standards.
Range of Motion analysis of the Endo-Model® Rotating Hinge Knee System	Not explicitly detailed, but implied to meet standards.
Constraint testing (for constrained prosthesis)	Not applicable/necessary.
Overall Conclusion of Non-Clinical Testing:	Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices.

2. Sample Size for the Test Set and Data Provenance

Sample Size: The document mentions "test samples" for the mechanical testing, specifically stating "All Endo-Model® Rotating Hinge Knee System test samples". However, the exact number of samples (the test set size) for each specific test (wear, fatigue, fretting, etc.) is not specified in this document.
Data Provenance: The testing was non-clinical performance testing, likely conducted by the manufacturer (Waldemar Link GmbH & Co. KG) in Germany, as part of their submission to the FDA. It is not patient data (retrospective or prospective).

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

This question is not applicable. The "ground truth" for this type of mechanical device is established through physical engineering tests against established industry standards and specifications (e.g., ISO, ASTM), not through expert clinical consensus or interpretation of patient data.

4. Adjudication Method for the Test Set

This question is not applicable. As the testing is physical mechanical evaluation against defined standards, there is no need for expert adjudication in the way it would be for AI output or clinical data. The "adjudication" is met by verifying test results against numerical or qualitative pass/fail criteria from the standards.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating the impact of an AI system on human readers' diagnostic performance, which is not applicable to a knee implant device.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

No, a standalone study in the context of an "algorithm only" was not done. This device is a physical implant, not an algorithm. The non-clinical performance tests are "standalone" in the sense that they evaluate the device itself without human interaction beyond its intended use.

7. Type of Ground Truth Used

The "ground truth" for this device's acceptance is based on engineering standards and specifications (e.g., ISO 14243-1 and -2, ISO 14879, ASTM F1800, ASTM F1875-98) for mechanical properties, wear resistance, and fatigue strength. It is not clinical expert consensus, pathology, or outcomes data in the context of proving initial device efficacy for market clearance.

8. Sample Size for the Training Set

This question is not applicable. The device is not an AI algorithm that requires a training set.

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

This question is not applicable. The device is not an AI algorithm.

Summary

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

January 30, 2015

Waldenmar Link GmbH & Co. KG Dr. Thomas Mehler Director Quality Management Barkhausenweg 10 22339 Hamburg Germany

Re: K143179

Trade/Device Name: The LINK® Endo-Model® Knee System Regulation Number: 21 CFR 888.3510 Regulation Name: Knee joint femorotibial metal/polymer constrained cemented prosthesis Regulatory Class: Class II Product Code: KRO Dated: November 3, 2014 Received: November 4, 2014

Dear Dr. Mehler:

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

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Page 2 – Dr. Thomas Mehler

(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 (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 contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. 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 Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely vours.

VincentJ. Devlin -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) K143179

Device Name

The LINK® Endo-Model® Knee System

Indications for Use (Describe)

The LINK® Endo-Model® Rotating Hinge and Modular Rotating Hinge Knee System are indicated for the following conditions:

1. Bone necroses.
1. Bicondylar arthrosis by partly damaged collateral ligaments
1. Revision after primary total knee replacement.
1. Revision surgery after hinge knee or rotational knee joint.
1. Revision surgery by insufficient / inadequate bone mass.
1. Arthrosis of patella flange.
1. Valgus/Varus deformities <10°.
1. Valgus/Varus deformities 10-15°.
1. Valgus/Varus deformities 15-20°.

The LINK® Endo-Model® Non-Rotating Hinge and Modular Non-Rotating Hinge Knee System are indicated for the following conditions:

1. Bone necroses.
1. Bicondylar arthrosis by completely damaged ligaments and muscular instability.
1. Revision after primary total knee replacement.
1. Revision surgery after hinge knee or rotational knee joint.
1. Revision surgery by insufficient / inadequate bone mass.
1. Arthrosis of patella flange.
1. Valgus/Varus deformities <10°.
1. Valgus/Varus deformities 10-15°.
1. Valgus/Varus deformities 15-20°.
1. Valgus/Varus deformities 20-30°.

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

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This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

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510(k) Summary

510(k) Submitter:	Waldemar Link GmbH & Co. KGBarkhausenweg 1022339 Hamburg, GermanyPhone: +49-40-539950Facility Registration #:3004371426 (Oststraße 4-10)
Contact Person:	Waldemar Link GmbH & Co. KGStefanie Reimers (Regulatory Affairs)Oststraße 4-10Norderstedt, GERMANY 22844Phone: +49-40 53995-530Fax: +49-40 53995-174E-Mail: S.Reimers@linkhh.de
Date Prepared:	November 3rd, 2014
Trade Name:	LINK® Endo-Model® Knee System
Common Name:	Total Knee Prosthesis
Classification Name:	Knee joint femorotibial metal/polymer constrained cementedprosthesis; 21 CFR §888.3510, product code KRO
Classification and Panel:	Class II, Orthopedic / 87
Predicate Devices:	NexGen® Complete Knee Solution Rotating Hinge Knee,manufactured by Zimmer, K013385, cleared January 9, 2002
Device Description:	The LINK® Endo-Model® Knee System is constrained anti-luxation total knee prosthesis.Retaining the low friction principle, the physiological movement of the rotational knee prosthesis is optimal because the pivot point is within the physiological area. Flexion and rotation of the rotational knee prosthesis take place in a cross joint.The LINK® Endo-Model® Knee System consists of Femoral and Tibial Components, Modular Stems, Femoral Segments and Proximal Tibial Spacers and Segments. The modular components are interchangeable allowing for independent positioning. The Modular Stems are available in a variety of diameters and lengths in cemented or cementless version. Special Femoral Segments for revision surgery of resurfacing knee implants and for tumor cases are available in a variety of heights. Proximal Tibial Spacers and Segments are used to act as a spacer for the missing bone where surgical reasons require the removal bone.

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The LINK® Endo-Model® Knee System is available in four (4) different knee joint versions:

Rotating Hinge Knee Standard (Non-Modular) -Version
Non-Rotating Hinge Knee Standard (Non-Modular) -Version
Rotating Hinge Knee Modular Version -
Non-Rotating Hinge Knee Modular Version -

The LINK® Endo-Model® Knee System is indicated for Indications for Use: patients with severe joint diseases with limitation of mobility due to degenerative, rheumatoid or post-traumatic arthrosis or arthritis. Joint fractures which disallow an osteosynthetic reconstruction. This device is intended for cemented use only unless a cementless modular stem is indicated for use.

The LINK® Endo-Model® Rotating Hinge and Modular Rotating Hinge Knee System are indicated for the following conditions:

1. Bone necroses.

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1. Bicondylar arthrosis by partly damaged collateral ligaments
Revision after primary total knee replacement. 3)
Revision surgery after hinge knee or rotational knee joint. 4)
Revision surgery by insufficient / inadequate bone mass. 5)
1. Arthrosis of patella flange.
1. Valgus/Varus deformities <10°.
1. Valgus/Varus deformities 10-15°.
1. Valgus/Varus deformities 15-20°.

The LINK® Endo-Model® Non-Rotating Hinge and Modular Non-Rotating Hinge Knee System are indicated for the following conditions:

1. Bone necroses.
1. Bicondylar arthrosis by completely damaged ligaments and muscular instability.
Revision after primary total knee replacement. 3)
1. Revision surgery after hinge knee or rotational knee joint.
Revision surgery by insufficient / inadequate bone mass. 5)
Arthrosis of patella flange. 6)
1. Valgus/Varus deformities <10°.
1. Valgus/Varus deformities 10-15°.
1. Valgus/Varus deformities 15-20°.
1. Valgus/Varus deformities 20-30°.

Comparison to Predicate Device: The LINK® Endo-Model® Knee System is substantially equivalent to the commercially available device NexGen® Rotating Hinge Knee (RHK) in that both have similar indications, design (both are constrained, rotating hinge knee prostheses), materials and mechanical safety. Both devices are intended for cemented use only.

Performance Data: Non-Clinical Performance and Conclusions:

Non-Clinical performance testing was conducted with consideration to Draft Guidance For The Preparation of Premarket Notifications (510(k)s) for cemented, semiconstrained Total Knee Prostheses, April 1993 and Guidance Document for Knee Joint patellofemorotibial and femorotibial metal/polymer porous-coated uncemented Prostheses, January 16, 2003

Non-clinical performance testing included: Tibial Bearing Component wear tests per ISO 14243-1 and -2; Tibial Baseplate Component fatigue tests per ISO 14879 and ASTM F1800 and Modular Connections, Fretting, and Corrosion Testing per ASTM F1875-98, Tibiafemoral and Patellofemoral contact area / stress analyses at different

{7}------------------------------------------------

angles of flexion and Range of Motion analysis of the Endo-Model® Rotating Hinge Knee System.

Constraint testing is not applicable to a constrained prosthesis. This test was not necessary.

All Endo-Model® Rotating Hinge Knee System test samples completed the 10 million cycles Tibial Baseplate Fatigue Strength testing without evidence of fracture or cracking.

The results of non-clinical performance testing demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices.

Clinical Performance and Conclusions:

There was no clinical performance testing required for this device.

Conclusion: The subject LINK® Endo-Model® Knee System is substantially equivalent to the predicate devices identified in this premarket notification.

5-5

Regulation Number and Section

§ 888.3510 Knee joint femorotibial metal/polymer constrained cemented prosthesis.

(a)
Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits translation or rotation in one or more planes and has components that are linked together or affined. This generic type of device includes prostheses composed of a ball-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a ball at the head of a column rising from the stemmed tibial component. The ball, the column, the tibial plateau, and the stem for fixation of the tibial component are made of an alloy, such as cobalt-chromium-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the femoral component's flat outer surface. The flat outer surface of the tibial component abuts both a reciprocal flat surface within the cavity of the femoral component and flanges on the femoral component designed to prevent distal displacement. The stem of the femoral component is made of an alloy, such as cobalt-chromium-molybdenum, but the socket of the component is made of ultra-high molecular weight polyethylene. The femoral component has metallic runners which align with the ultra-high molecular weight polyethylene tracks that press-fit into the metallic tibial component. The generic class also includes devices whose upper and lower components are linked with a solid bolt passing through a journal bearing of greater radius, permitting some rotation in the transverse plane, a minimal arc of abduction/adduction. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.