(28 days)
The Molded Metal-back Tibial components are intended to replace the patient's proximal tibia during primary or revision total knee arthroplasty. This device has been designed to substitute for the posterior stability of the Posterior Cruciate Ligament (PCL) and is intended for cemented application.
The OPTETRAK® Total Knee Systems are indicated for use in skeletally mature individuals undergoing primary surgery for total knee replacement due to osteoarthritis, osteonecrosis, rheumatoid arthritis and/or post-traumatic degenerative problems. They are also indicated for revision of failed previous reconstructions where sufficient bone stock and soft tissue integrity are present.
In materials and design, the proposed Molded Metal-back Tibial components are a combination of:
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The articulating surfaces of the Exactech Optetrak Tibial Tray Insert components (K933610 and K011976)
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The tibial stem of the Cemented Finned Tibial Tray components (K932776 and K011976).
The device modifications presented in this Special 510(k) represent changes to the posterior stabilized, modular tibial insert and finned tibial tray components of the Optetrak Total Knee (K932776, K933610 and K011976). No changes were made to the femoral or patellar components of this system.
The proposed device modifications involve:
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Modification to the portion of the modular assembly distal to the proximal articulating surface and proximal to the distal finned stem.
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Revised cement fixation undercuts on the distal portion of the component
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Integration of geometric undercuts to form a mechanical interlock between the UHMWPE and metallic portions of the component
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A change in material of the finned stem portion from titanium alloy to cobaltchromium (CoCr)
No modifications have been made to the articular surface of the UHMWPE that interfaces with the femoral components. Nor have any configuration changes been made to the finned stem portion of the tibial bone interface.
There have been no changes to the material of the predicate Optetrak Total Knee bearing surface. Like the predicate Optetrak Total Knee tibial inserts, the proposed bearing surface is manufactured of Ultra-High Molecular Weight Polyethylene (UHMWPE) conforming to ASTM F648.
This document describes a Special 510(k) submission for a line extension to the Exactech Optetrak Total Knee System, specifically for "Molded Metal-back Tibial Components." The application focuses on demonstrating substantial equivalence to previously cleared predicate devices through design modifications and performance testing.
Here's an analysis of the provided information concerning acceptance criteria and supporting studies:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria/Test Description | Reported Device Performance |
|---|---|---|
| Functional Performance | Adequate for anticipated in vivo loading conditions. | "Functional testing was conducted to verify that the implant performance would be adequate for anticipated in vivo loading." The conclusion drawn is that "the Molded Metal-back Tibial Components are substantially equivalent to other devices legally marketed in the United States, most notably Exactech's predicate Optetrak products." This implies the device met the functional performance expectations set by the predicate devices. |
| Material Equivalence | The articulating surfaces of the Exactech Optetrak Tibial Tray Insert components (K933610 and K011976) and the tibial stem of the Cemented Finned Tibial Tray components (K932776 and K011976) were used as references for the proposed design. Material for the bearing surface should be Ultra-High Molecular Weight Polyethylene (UHMWPE) conforming to ASTM F648. | The proposed device modifications combine the articulating surfaces of K933610 and K011976 and the tibial stem of K932776 and K011976. The finned stem portion was changed from titanium alloy to cobalt-chromium (CoCr). No changes were made to the articular surface of the UHMWPE. The proposed bearing surface is manufactured of UHMWPE conforming to ASTM F648, "Like the predicate Optetrak Total Knee tibial inserts." This suggests meeting the material criteria by either maintaining or establishing equivalence to the predicate. |
| Design Equivalence (Modifications) | Modifications should not negatively impact safety and effectiveness compared to predicate devices. The modifications include changes to the modular assembly, revised cement fixation undercuts, integration of geometric undercuts for mechanical interlock, and a material change for the finned stem. | Explicitly stated modifications are: 1) Modification to the portion of the modular assembly distal to the proximal articulating surface and proximal to the distal finned stem. 2) Revised cement fixation undercuts on the distal portion of the component. 3) Integration of geometric undercuts to form a mechanical interlock between the UHMWPE and metallic portions of the component. 4) A change in material of the finned stem portion from titanium alloy to cobalt-chromium (CoCr). The unchanged aspects include the articular surface of the UHMWPE and the configuration of the finned stem's bone interface. These changes were deemed acceptable through the comparative analysis and functional testing. |
2. Sample Size Used for the Test Set and the Data Provenance
The document does not specify a sample size for any "test set" in the context of clinical testing with human subjects or a defined dataset for AI/algorithm performance. The evaluation is primarily based on functional testing of the implant, design comparisons to predicate devices, and material specifications.
The data provenance is prospective functional testing conducted by the manufacturer, Exactech, Inc. There is no indication of retrospective or prospective clinical human data, nor is there any mention of country of origin for such data.
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 in the document. The evaluation is focused on the mechanical and material properties of a prosthetic device, not on interpreting images or making diagnoses that would require expert-established ground truth.
4. Adjudication Method for the Test Set
This information is not applicable and not provided. Adjudication methods are typically used in clinical studies or for establishing ground truth for AI algorithms, which are not described here.
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
This information is not applicable and not provided. This document pertains to a knee prosthesis and does not involve AI or human "readers" of medical images or data.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
This information is not applicable and not provided. This document describes a physical medical device, not a software algorithm.
7. The Type of Ground Truth Used
The "ground truth" for this device appears to be based on:
- Validated engineering principles and functional testing standards: The performance data summary mentions "Functional testing was conducted to verify that the implant performance would be adequate for anticipated in vivo loading." This implies comparison against established biomechanical standards and expected performance in the human body.
- Material specifications: Conformance to ASTM F648 for UHMWPE.
- Design characteristics of legally marketed predicate devices: The primary method of showing substantial equivalence is by demonstrating that the new device's design, materials, and functional performance are similar to or equivalent to existing, cleared devices (K933610, K011976, K932776).
There is no mention of expert consensus, pathology, or outcomes data as a ground truth for the technical evaluation presented in this 510(k) summary.
8. The Sample Size for the Training Set
This information is not applicable and not provided. There is no mention of a "training set" as this is not an AI/machine learning device.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable and not provided. As there is no training set mentioned, this question is irrelevant to the provided document.
§ 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.