(179 days)
The U2 Total Knee system is indicated in knee arthroplasty for reduction or relief of pain and/or improved knee function in skeletally mature patients with severe knee pain and disability due to rheumatoid arthritis, osteoarthritis, primary and secondary traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis of the femoral condyle or pseudogout, posttraumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy, moderate valgus, varus, or flexion deformities. This device may also be indicated in the salvage of previously failed surgical attempts if the knee can be satisfactorily balanced and stabilized at the time of surgery. This device is a single use implant and intended for cementless use only.
U2 Femoral Component, CR, Porous Coated, Additional Sizes is an extension of cleared "UNITED" U2 Femoral Component, CR, Porous Coated (K140075). The indications, major design features, materials, major manufacture processing and methods of this subject are identical to the cleared U2 Femoral Component, CR, Porous Coated (K140075). The cleared femoral components are available in size #1, #2, #3, #7, and the subjected femoral components are the intermediate sizes for #1.5, #2.5, #4.5, #5.5 and #6.5.
The provided text is related to a 510(k) premarket notification for a medical device: "U2 Femoral Component, CR, Porous Coated, Additional Sizes." This device is a knee joint prosthesis.
Based on the nature of this document (a 510(k) summary for a Class II knee prosthesis) and the content, this is not a document that describes an AI/ML medical device, nor does it detail a clinical study with diagnostic performance metrics (e.g., sensitivity, specificity, AUC) for such a device.
Instead, this document focuses on demonstrating substantial equivalence to a previously cleared predicate device (K140075) for additional sizes of a physical implant. The "performance data" mentioned refers to mechanical properties and engineering analysis, not diagnostic accuracy studies.
Therefore, most of the questions about acceptance criteria for AI/ML performance, sample sizes for test/training sets, expert adjudication, MRMC studies, and ground truth types are not applicable to this document.
However, I can extract the relevant information from the provided text regarding the device and its compliance:
1. A table of acceptance criteria and the reported device performance
The document does not provide a table of precise acceptance criteria in terms of numerical thresholds for diagnostic performance (as would be typical for an AI/ML device). Instead, it states that the device was evaluated to conform to FDA guidance for mechanical properties.
| Acceptance Criteria (General) | Reported Device Performance |
|---|---|
| Mechanical properties conformity to FDA guidance: "Class II Special Controls Guidance Document: Knee Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses." | "The analysis results demonstrate that the adding intermediate sizes would not affect the safety and effectiveness." |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
Not applicable. This is not an AI/ML diagnostic device, so there's no "test set" in that context. The "performance data" refers to mechanical testing/analysis of physical implants, not data samples.
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. There is no ground truth, expert consensus, or clinical diagnostic evaluation described for this physical implant.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable.
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.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
Not applicable. The "ground truth" here would essentially be established engineering principles and mechanical testing standards.
8. The sample size for the training set
Not applicable.
9. How the ground truth for the training set was established
Not applicable.
Summary based on the provided document:
- Device Type: Physical medical implant (U2 Femoral Component, CR, Porous Coated, Additional Sizes) - a knee joint prosthesis.
- Purpose of Submission: To add intermediate sizes to an already cleared femoral component (K140075), demonstrating substantial equivalence.
- Performance Evaluation: Focused on mechanical properties testing and analysis to ensure the additional sizes do not negatively affect safety and effectiveness. This evaluation was conducted to conform to the "Class II Special Controls Guidance Document: Knee Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses."
- Methodology: Engineering analysis and mechanical testing, not clinical trials or diagnostic performance studies involving patient data or expert reads.
§ 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented 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 is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra high molecular weight polyethylene tibial bearing is rigidly secured to the metal tibial base plate.(b)
Classification. Class II (special controls). The special control is FDA's guidance: “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA.” See § 888.1 for the availability of this guidance.