(185 days)
These devices are 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, and 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.
CR, LPS, and CR-Flex porous coated components may be used cemented or uncemented (biological fixation) while the CR and CR-Flex hydroxyapatite/tricalcium (HA/TCP) porous coated femoral or tibial baseplate components may only be used uncemented. All other femoral, tibial baseplate and all-polyethylene patella components are indicated for cemented use only.
The devices included in this 510(k), are identical to their predicates except for the addition of HA/TCP.
This document describes a 510(k) premarket notification for the NexGen® Porous, HA/TCP, Uncemented Femoral and Tibial Baseplate Components.
Here's an analysis of the provided information regarding acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
The document does not provide a table of acceptance criteria or specific reported device performance metrics in the way one would expect for a diagnostic AI device. This is because the submission is for a medical implant (total knee prosthesis components), not a diagnostic AI device. The regulatory pathway for this type of device relies on demonstrating substantial equivalence to a predicate device rather than meeting specific performance criteria against a ground truth.
The "performance" in this context is implicitly the expected mechanical and biological performance of the implant, which is deemed acceptable if it's "substantially equivalent" to an already cleared predicate device.
Table of Comparison (derived from the text):
| Feature/Criteria | Predicate Device: NexGen® Porous, Uncemented Femoral and Tibial Baseplate Components (K031061) | Current Device: NexGen® Porous, HA/TCP, Uncemented Femoral and Tibial Baseplate Components | Acceptance Status |
|---|---|---|---|
| Device Description | Not explicitly stated, but assumed to be porous-coated uncemented femoral and tibial baseplate components. | Identical to predicates except for the addition of HA/TCP. | Met (Addition of HA/TCP is the key difference) |
| Intended Use | Not explicitly stated for predicate, but assumed to be for total knee prosthesis as described in K031061. | Identical indications for use as described in the summary. | Met (Same intended use) |
| Non-Clinical Performance | Met requirements for K031061. | No additional testing was required. | Met (Based on similarity, no new non-clinical data needed) |
| Clinical Performance | Met requirements for K031061. | Clinical data and conclusions were not needed for this device. | Met (Based on similarity, no new clinical data needed) |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
There was no separate "test set" or study in the traditional sense for evaluating new performance data. The device was deemed substantially equivalent based on its physical similarity to a predicate device and the addition of a well-understood material (HA/TCP). Therefore, information like sample size, data provenance, retrospective/prospective nature, or country of origin is not applicable to this 510(k) submission.
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. As there was no specific "test set" and no new performance data generated for this substantial equivalence submission, there was no need for experts to establish ground truth.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. No test set or independent adjudication was performed as part of this submission. The "adjudication" was effectively the FDA's review of the submission and comparison to the predicate device.
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 component, not an AI-powered diagnostic tool. Therefore, MRMC studies and AI assistance are not relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This device is a medical implant, not an algorithm or AI.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
Not applicable. For this 510(k) submission, the "ground truth" for the device's acceptability was its demonstrated substantial equivalence to a legally marketed predicate device. This is based on material composition, design intent, and intended use being sufficiently similar to not pose new questions of safety or effectiveness.
8. The sample size for the training set
Not applicable. This submission is not for an AI/ML device, so there is no training set in the AI context.
9. How the ground truth for the training set was established
Not applicable. There is no training set for this device.
§ 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.