(182 days)
This device is part of a total knee replacement system utilized in treating patients who are candidates for primary cemented total knee arthroplasty or revision arthroplasty where bone loss is minimal and the collateral ligaments are intact. It is intended to aid the surgeon in relieving the patient of knee pain and restoring knee joint function.
Noninflammatory degenerative joint disease including osteoarthritis or traumatic arthritis
Avascular necrosis of the femoral condyle
Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy
Moderate valgus, varus or flexion deformities
Rheumatoid arthritis
Treatment of fractures that are unmanageable using other techniques.
The 3D Knee is comprised of a femoral and a tibial component. The femoral component is manufactured from CoCr alloy conforming to ASTM F75, is available in 6 sizes (2-12) and is provided in left and right configurations. The femoral component is designed to match the condyles of the tibial insert for greater congruency and is similar to the Foundation Knee cleared in K923277.
The 3D Knee tibial inserts are manufactured from ultra high molecular weight polyethylene (UHMWPE) that conforms to ASTM F648. The tibial inserts are available in 6 sizes (2-12) and 5 thicknesses (9-19) and are provided in right and left orientations. The tibial in design to the Foundation Lateral Pivot Insert cleared in K000590. This insert is intended to more closely complement the kinematics of the resurfaced knee, allowing rotation about the lateral condyle and increased congruency of the lateral condyle. The baseplate attachment mechanism is the previously cleared Foundation Knee System inserts; therefore, the attachment strength is the same.
The provided document describes a 510(k) premarket notification for a medical device called "3D Knee". It focuses on establishing substantial equivalence to previously marketed predicate devices rather than proving performance against specific acceptance criteria through clinical studies in the way one might for an AI/ML device.
Here's an analysis based on the information provided:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state "acceptance criteria" in the traditional sense of performance metrics for a novel technology (e.g., sensitivity, specificity for an AI algorithm). Instead, the "acceptance criteria" for this device (3D Knee) are implicitly about demonstrating substantial equivalence to existing, legally marketed predicate devices.
The reported device performance is framed in terms of its similarity in design, materials, and indications for use to the predicates.
| Acceptance Criteria (Implicit for Substantial Equivalence) | Reported Device Performance (as stated in the 510(k)) |
|---|---|
| Design Similarity: The new device's design is similar to the predicate device(s). | The 3D Knee femoral component design "is similar to the Foundation Knee cleared in K923277." The tibial insert design "is similar to the Foundation Lateral Pivot Insert cleared in K000590." The baseplate attachment mechanism is the "previously cleared Foundation Knee System inserts." |
| Material Similarity: The new device uses materials similar to the predicate device(s). | The femoral component is manufactured from "CoCr alloy conforming to ASTM F75," which is a standard material for such implants. The tibial inserts are manufactured from "ultra high molecular weight polyethylene (UHMWPE) that conforms to ASTM F648," also common. (Implied similarity to predicate materials as no new materials are highlighted as different). |
| Intended Use Similarity: The new device has the same or substantially similar intended use as the predicate device(s). | The 3D Knee is "part of a total knee replacement system utilized in treating patients who are candidates for primary cemented total knee arthroplasty or revision arthroplasty where bone loss is minimal and the collateral ligaments are intact." This is consistent with the intended use of total knee systems. |
| Performance (Mechanical): The mechanical performance is equivalent or superior. | "Mechanical analysis was completed to determine substantial equivalence." (Specific results are not detailed in this summary, but the conclusion is that it met the equivalence standard). |
2. Sample sized used for the test set and the data provenance
- Test Set Sample Size: Not applicable in the context of this 510(k) summary. This document does not describe a clinical study with a "test set" in the sense of a dataset for evaluating an algorithm or a device's performance against ground truth. Instead, it relies on non-clinical mechanical testing and comparison to predicate devices.
- Data Provenance: Not applicable for the reasons above.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: Not applicable. No "ground truth" was established by experts for a test set in the context of this submission. Substantial equivalence relies on regulatory review of design, materials, and non-clinical testing data compared to established predicate devices.
- Qualifications of Experts: Not applicable.
4. Adjudication method for the test set
- Adjudication Method: Not applicable. There was no test set requiring multi-expert adjudication.
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
- MRMC Study: No, an MRMC comparative effectiveness study was not done. This device is a mechanical orthopedic implant, not an AI-assisted diagnostic or therapeutic tool.
- Effect Size: Not applicable.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance: No, this is not an algorithm. This question is not applicable to an orthopedic implant.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- Type of Ground Truth: No "ground truth" (in the sense of a definitive diagnostic or clinical outcome label) was explicitly used or established in this 510(k) submission. The basis for substantial equivalence is the safety and effectiveness of the predicate devices that have already been legally marketed and demonstrated performance through their own regulatory pathways (which often included clinical data or adherence to standards in their initial assessment). For the 3D Knee, the "evidence" is primarily the detailed comparison of its design, materials, and mechanical testing results against the established safety and performance of the predicates.
8. The sample size for the training set
- Training Set Sample Size: Not applicable. This is not an AI/ML device.
9. How the ground truth for the training set was established
- Ground Truth for Training Set: Not applicable. This is not an AI/ML device.
Summary of the Study Proving Device Meets "Acceptance Criteria":
The "study" proving the 3D Knee meets its (implicit) acceptance criteria for market clearance under 510(k) is a non-clinical mechanical analysis and a comparative assessment against legally marketed predicate devices.
- Non-Clinical Testing: "Mechanical analysis was completed to determine substantial equivalence." While the specific tests (e.g., fatigue strength, wear properties, fixation strength) are not detailed in this summary, the FDA's clearance indicates these tests were deemed sufficient to show the device performed comparably to its predicates.
- Basis for Substantial Equivalence: The primary "proof" is the detailed comparison presented to the FDA, demonstrating that the 3D Knee is "similar in design, materials and indications to the Foundation Knee System (K923277) and the Lateral Pivot Insert (K000590)." This comparative analysis essentially leverages the prior regulatory approval and established safety/effectiveness of the predicate devices. The FDA concurred with this assessment, leading to the device's clearance.
Essentially, for this type of device and regulatory pathway, the "acceptance criteria" are met by demonstrating that the new device is as safe and effective as a device already on the market, primarily through engineering principles and testing, rather than new human clinical trials.
§ 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.