(82 days)
The DePuy Attune™ Total Knee System is intended for cemented use as a total knee replacement system.
Candidates for total knee replacement include patients with a severely painful and/ or severely disabled joint resulting from osteoarthritis, posttraumatic arthritis, rheumatoid arthritis, or a failed previous implant.
The Attune medialized dome and medialized anatomic patellae are available in sizes 29, 32, 35, 38, and 41mm. The fixation surface incorporates 3 pegs to provide stability and recessed cement pockets for enhanced cement fixation. The patella components are manufactured from AOX ultra high molecular weight polyethylene conforming to ASTM F648. The articular surface is offset medially proportional to the size of the component.
The Attune CR Knee System is designed to accommodate knee flexion to 150 degrees in those patients able to attain a high degree of knee flexion.
The provided text describes a 510(k) premarket notification for a medical device, the DePuy Attune™ Total Knee System, specifically focusing on the medialized dome and medialized anatomic patellae components. The submission aims to establish substantial equivalence to previously marketed devices.
Based on the provided information, here's an analysis regarding acceptance criteria and study details:
The document does not describe acceptance criteria in terms of performance metrics (sensitivity, specificity, accuracy, etc.) or a study proving the device meets these criteria in the context of an AI/human reader study.
Instead, this is a Premarket Notification (510(k)) for a physical medical device (knee implant components). The "acceptance criteria" here refer to the regulatory thresholds for establishing substantial equivalence to predicate devices. The "study" proving acceptance is the non-clinical functional testing performed to demonstrate this equivalence.
Therefore, many of the requested points (e.g., sample size for test/training sets, number of experts for ground truth, MRMC study, standalone algorithm performance, AI assistance) are not applicable to this type of device submission.
Here's a breakdown of the relevant information provided:
1. A table of acceptance criteria and the reported device performance
The "acceptance criteria" in this context are for demonstrating substantial equivalence to predicate devices for a physical orthopedic implant. They are not defined by specific performance metrics like sensitivity or specificity.
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Material Equivalence: Must use materials substantially equivalent to predicate devices, conforming to relevant standards. | Met: "AOX UHMWPE conforming to ASTM F648" is used. The predicate devices also use "AOX UHMWPE conforming to ASTM F648" (for Attune predicate) or similar (unspecified for others, but implied acceptable). |
| Design Characteristics Equivalence: Key design features (e.g., fixation, articular surface offset) must be similar to predicate devices. | Met: |
- Articular Surface Offset: "medial" for the new device, "medial" for Kinemax predicate.
- Fixation Surface: "Cemented" for the new device, "Cemented" for Sigma predicate.
- Sizes: Available in 29, 32, 35, 38, 41 mm, which is comparable to predicate sizes (e.g., Attune predicate: 29, 32, 35, 38, 41mm; Sigma: 32, 35, 38, 41mm; NexGen: 29, 32, 35, 38, 41mm).
- Overall Design: "similar to the predicate devices including design and AOX material." |
| Functional Performance Equivalence: Must perform similarly to predicate devices under anticipated in vivo loading. | Met: "Functional testing was conducted in compliance with FDA guidance... to verify that the implant performance would be substantially equivalent to predicate devices for anticipated in vivo loading via constraint and contact tests." |
| Intended Use & Indications for Use Equivalence: Must have the same fundamental intended use and indications. | Met: Intended use is "Total knee replacement is intended to provide increased patient mobility and reduced pain by replacing the damaged knee joint articulation..." and indications for use cover "patients with a severely painful and/or severely disabled joint resulting from osteoarthritis, post-traumatic arthritis, rheumatoid arthritis, or a failed previous implant," which is standard for total knee replacements and aligns with the purpose of predicate devices. |
2. Sample sized used for the test set and the data provenance
- Test Set (Non-Clinical): Not applicable in the sense of a patient data set for AI. The "test set" here refers to the physical devices subjected to non-clinical functional testing. The document does not specify the number of physical samples tested.
- Data Provenance: Not applicable in the sense of patient data. The "data" comes from engineering and biomechanical testing of the physical implant components.
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. Ground truth in this context is established through engineering specifications, material standards (ASTM F648), and biomechanical testing protocols defined by FDA guidance for orthopedic implants ("Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses: Guidance for Industry and FDA"). It does not involve human expert interpretation of images or clinical data for performance assessment.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. Adjudication is not relevant for this type of non-clinical, functional testing.
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
- No, not applicable. This is a physical medical device, not an AI-assisted diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No, not applicable. This is a physical medical device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for this device, to establish substantial equivalence, is based on:
- Published ASTM material standards (ASTM F648) for the polyethylene.
- FDA guidance documents for non-clinical testing of knee implants (e.g., "Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses: Guidance for Industry and FDA").
- Established engineering principles and biomechanical testing methods (e.g., constraint and contact tests).
- Comparison to the known characteristics and approved status of predicate devices.
8. The sample size for the training set
- Not applicable. There is no "training set" in the context of an AI model for this physical device.
9. How the ground truth for the training set was established
- Not applicable. There is no "training set" or associated ground truth establishment for an AI model.
Summary of the Study Proving Acceptance:
The submission relies on non-clinical testing to prove the device meets the (implied) acceptance criteria of substantial equivalence.
- Type of Study: Non-clinical functional testing.
- Objective: To verify that the implant performance (specifically the medialized dome and medialized anatomic patellae components) would be substantially equivalent to predicate devices for anticipated in vivo loading.
- Methods: Performed via "constraint and contact tests." The testing was conducted "in compliance with FDA guidance, Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses: Guidance for Industry and FDA."
- Results: The testing presumably demonstrated that the new components perform comparably to the predicate devices, leading to the FDA's determination of substantial equivalence.
- Clinical Testing: "None provided as it was not necessary to determine substantial equivalence between the Attune Knee System's medialized dome and medialized anatomic patellae and the predicate devices." This highlights that for this type of device and the 510(k) pathway, non-clinical data was sufficient to establish equivalence for regulatory clearance.
§ 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.