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Trabecular Metal Tibial Cone Augments are intended for use where severe degeneration, trauma, or other pathology of the knee joint indicates total knee arthroplasty. When used with the NexGen Complete Knee Solution - Rotating Hinge Knee (RHK) System, the Trabecular Metal Tibial Cone Augments are for cemented use only. When used with the NexGen Complete Knee Solution - Legacy Constrained Condylar Knee System, the Trabecular Metal Tibial Cone Augments are for cementless or cemented use.

The existing, commercially available NexGen® Trabecular Metal™ Tibial Cone Augments are manufactured wholly of Trabecular Metal porous tantalum, the same material that comprises numerous medical devices intended for use in orthopedic applications. The devices which are the subject of this 510(k), the modified NexGen Trabecular Metal Tibial Cone Augments are also manufactured of the same Trabecular Metal material, using the same methods as the predicate device. The existing, commercially available NexGen Trabecular Metal Tibial Cone Augments have tapered posterior, medial and lateral walls. The periphery of the inferior surface is smaller than that of the superior surface. A similar taper pattern is also present in the modified tibial cones.

Both the modified tibial cones augments and the existing, commercially available tibial cone augments are to be used in conjunction with Zimmer's NexGen® Complete Knee Systems- both the Legacy® Constrained Condylar Knee (LCCK) Stemmed Tibial Bases and the tibial component of Zimmer's Rotating Hinge Knee (RHK) System. Fixation of all of the cone augments to the tibial implant is accomplished by cementing the superior portion of the augment to the underside of the tibial baseplate. Apposition of the cone to bone inside the medullary canal is with or without cement when used with the LCCK tibial implant and with cement for the RHK tibial implant. With all of these tibial cone augments the LCCK tibial baseplate inferior surface must be cemented to the bone and the required stem extensions can either be cemented or press-fit.

The existing, commercially available augments come in four medium & large sizes, two height options and stepped augments. They can be used in conjunction with Zimmer's LCCK or RHK Knee Systems.

Here's an analysis of the provided text regarding the acceptance criteria and study for the Zimmer Trabecular Metal™ Tibial Cone Augments:

1. Table of Acceptance Criteria and Reported Device Performance

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

The study described is a Finite Element Analysis (FEA), which is a computer simulation, not a study involving physical samples or human patients as a "test set" in the traditional sense. Therefore, concepts like "sample size" for a test set and "country of origin of the data" are not directly applicable. The data provenance would be the computational models and parameters used in the FEA.

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

Since this was an FEA study, the concept of "ground truth" derived from expert review of patient data is not applicable. The "ground truth" for an FEA study would be the underlying physics and engineering principles validated through previous research and material properties. The document does not specify experts involved in establishing this, but it implies reliance on established engineering and biomechanical principles.

4. Adjudication Method for the Test Set

Not applicable for an FEA study, as there is no human interpretation of data for adjudication.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of Human Improvement with AI vs. Without AI Assistance

No, an MRMC comparative effectiveness study was not done. This device is a physical implant, not an AI or imaging diagnostic tool, so "human readers" and "AI assistance" are not relevant to this submission.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

Again, this is not applicable as the device is a physical implant. The "standalone" performance here refers to the mechanical performance of the implant itself, which was assessed through the FEA.

7. The Type of Ground Truth Used

The ground truth used in this context is computational modeling and engineering principles, specifically validated through a Finite Element Analysis (FEA). The results of the FEA are compared against predetermined requirements for mechanical performance.

8. The Sample Size for the Training Set

Not applicable in the context of an FEA study. FEA models are built based on material properties, design specifications, and biomechanical loads. There isn't a "training set" of data in the sense of machine learning.

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

As above, the concept of a "training set" doesn't directly apply. The "ground truth" for an FEA model would be based on well-established engineering principles, material science data for Trabecular Metal and bone, and biomechanical studies defining forces during gait. These parameters are inputs to the FEA, not derived from a "training set" in the typical sense.

Summary of the Study:

The study undertaken to demonstrate device performance was a comparative Finite Element Analysis (FEA). This computational modeling technique was used to simulate the mechanical behavior of the proposed modified tibial cone augments under "normal gait activities (walking and deep flexion)." The goal was to determine if the modified design met predefined mechanical performance requirements and to compare its performance to the predicate device, thereby supporting substantial equivalence. The document states that the FEA results demonstrated that the implants adequately meet the predetermined requirements established for its mechanical performance, thus supporting their substantial equivalence.

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The NexGen Trabecular Metal Tibial Cone Augments are indicated for use in the reconstruction of bony defects in knee reconstruction due to severe degeneration, trauma, or other pathology of the knee joint, and in the revision or salvage of failed, previously reconstructed knee procedures and implants. The Trabecular Metal Tibial Cone Augments are for cemented use only in the USA, and for cementless or cemented use outside the USA.

The NexGen Trabecular Metal Tibial Cone Augments are designed to be used in conjunction with Zimmer Inc.'s Legacy@ Stemmed Tibial Bases (LCCK) and Rotating Hinge Knee (RHK) tibial components. The subject devices are used to address proximal tibial cavitary defects encountered when implanting either of these two systems. The augments are manufactured from Trabecular Metal and have tapered posterior, medial and lateral walls. The periphery of the inferior surface is smaller than that of the superior surface. The augments are hollow such that they are to be filled with bone cement, and allow for placement of the stem and/or keel of the associated tibial base plate. Fixation of the augment to the tibial baseplate is accomplished by using bone cement. The inferior surface of the LCCK and RHK tibial baseplates must be cemented to bone. The Trabecular Metal Tibial Cone Augments are for cemented use along the bone in the USA, and for cementless or cemented use along the bone outside the USA.

This submission describes a medical device, the NexGen Trabecular Metal Tibial Cone Augments, and seeks to demonstrate its substantial equivalence to previously marketed predicate devices. This is a premarket notification for a medical device (510(k)), not a study to prove performance against specific acceptance criteria. Therefore, most of the requested information about a clinical study is not applicable to this document.

Here's a breakdown of the relevant information provided and how it addresses your request:

1. Table of Acceptance Criteria and Reported Device Performance:

This document does not provide a table of acceptance criteria and reported device performance for the NexGen Trabecular Metal Tibial Cone Augments. The submission aims to establish substantial equivalence to predicate devices rather than proving performance against specific, pre-defined acceptance criteria through a new study.

The closest statement to "reported performance" is:

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):

Not applicable. No new test set or clinical study was performed for this 510(k) submission on the subject device. The determination of substantial equivalence was based on an engineering analysis and previous testing of the material (Trabecular Metal) and other Trabecular Metal devices, not a specific clinical test set for these augments.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):

Not applicable. No clinical test set with ground truth established by experts was used for this submission.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

Not applicable. No clinical test set was used.

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 device is a passive implant (tibial cone augment), not an AI-powered diagnostic tool. Therefore, an MRMC study or assessment of AI assistance for human readers is irrelevant.

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

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

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):

Not applicable. No new ground truth was established for the subject device. The basis for the submission is demonstrating substantial equivalence through an engineering analysis and previously conducted testing on the material itself.

8. The sample size for the training set:

Not applicable. There was no "training set" in the context of an algorithm or AI model development. The basis of the submission is the material properties of Trabecular Metal and its prior use in other devices.

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

Not applicable. As there was no training set, there was no ground truth for a training set to be established.

In summary: This 510(k) submission for the NexGen Trabecular Metal Tibial Cone Augments relies on demonstrating substantial equivalence to existing predicate devices. This typically involves comparing device design, materials, manufacturing processes, and intended use. The submission states that "Testing of the subject devices were not performed" and instead, "Previous testing of Trabecular Metal and Trabecular Metal devices support a determination of substantial equivalence. An engineering analysis was provided to support this." This means the regulatory decision was made based on a comparison to known, safe, and effective devices already on the market, rather than a new clinical study with acceptance criteria and measured performance of this specific augment.

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