(21 days)
This device is indicated for patients with severe knee pain and disability due to:
- Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis.
- Collagen disorders and/or 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.
- The salvage of previously failed surgical attempts or for a knee in which satisfactory stability in flexion cannot be obtained at the time of surgery.
This device is indicated for cemented use only.
The proposed device is part of the NexGen system of semiconstrained, nonlinked knee prostheses.
The provided text is for a 510(k) premarket notification for a medical device, the NexGen® Prolong™ All-Poly Patella. This document concerns the substantial equivalence of the device to a predicate device, not a study proving it meets specific acceptance criteria in the way one might expect for a novel diagnostic device.
Here's an analysis based on the provided text, addressing your points:
1. A table of acceptance criteria and the reported device performance
The provided text does not list specific acceptance criteria or quantitative performance metrics for the NexGen® Prolong™ All-Poly Patella. Instead, it relies on the concept of substantial equivalence to a predicate device.
The "performance" criteria are essentially that the device is "safe and effective and is substantially equivalent to the predicate device."
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Safety and Effectiveness | Determined to be safe and effective |
| Substantial Equivalence to Predicate Device (K933785) | Substantially equivalent to the predicate device |
| Intended Use unchanged | Does not change the intended use |
| Fundamental Scientific Technology unchanged | Does not change the fundamental scientific technology |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document explicitly states: "Performance testing completed as part of the design assurance process demonstrated that this device is safe and effective and is substantially equivalent to the predicate device."
However, no specific sample size for a test set is mentioned, nor is the provenance of any data (e.g., country of origin, retrospective/prospective). The assessment appears to be based on non-clinical performance (design assurance testing) and direct comparison to the predicate device, rather than a clinical trial with a defined patient sample.
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. This submission is not based on a study requiring expert-established ground truth for a test set (e.g., interpreting medical images). It's a device modification where substantial equivalence is claimed through non-clinical testing and comparison to an established predicate.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. As there's no clinical test set with human interpretation requiring ground truth establishment, no adjudication method 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 total knee prosthesis, not an AI-assisted diagnostic tool. Therefore, MRMC studies and AI assistance are not relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. This device is a physical implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
Not explicitly stated in terms of "ground truth" for a clinical study. The determination of safety and effectiveness for substantial equivalence was based on:
- Non-Clinical Performance: "Performance testing completed as part of the design assurance process." The "ground truth" here would be engineering specifications, material properties, and biomechanical testing standards met during design assurance.
- Comparison to Predicate Device: The predicate device itself (Zimmer NexGen Knee System, K933785) provides the "ground truth" for established safety and effectiveness.
8. The sample size for the training set
Not applicable. This device is a physical knee prosthesis, not a machine learning model that requires a training set.
9. How the ground truth for the training set was established
Not applicable. As above, no training set for an algorithm was used.
§ 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.