(189 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.
CR, LPS and CR-Flex porous coated femoral or tibial baseplate components may be used cemented or uncemented (biological fixation). All other femoral, tibial baseplate and allpolyethylene patella components (including HA/TCP coated) are indicated for cemented use only.
This submission is for the uncemented use of NexGen porous total knee prostheses. All have already been cleared for cemented use.
Porous NexGen Cruciate Retaining (CR) Femoral Components
Porous NexGen CR 4-pegged Tibial Baseplate Components
Porous NexGen Stemmed Tibial Baseplate -Components
Porous NexGen CR-Flex Femoral -Components
Porous NexGen Legacy Posterior Stabilized (LPS) Femoral Components
Each of the above devices is part of a semiconstrained, non-linked condylar knee system. The CR devices are for use with a functional posterior cruciate ligament and the LPS device is for use with both cruciate ligaments excised.
These devices are identical to the predicate devices except for the uncemented indication for use.
The provided document is a 510(k) summary for the Zimmer NexGen® Porous, Uncemented Femoral and Tibial Baseplate Components. This submission focuses on the uncemented use of these knee prostheses, which had previously been cleared for cemented use.
No studies were conducted to prove the device meets acceptance criteria. The document explicitly states:
- Non-Clinical Performance and Conclusions: "No additional testing was required."
- Clinical Performance and Conclusions: "Clinical data and conclusions were not needed for this device."
The basis for clearance is substantial equivalence to predicate devices already on the market for cemented use. The device is identical to the predicate devices except for the uncemented indication for use. Therefore, no new acceptance criteria based on performance studies are described or met within this document.
Since no performance studies were conducted, the following information is not available in this document:
- Table of acceptance criteria and reported device performance: Not applicable as no new performance data was generated.
- Sample size used for the test set and the data provenance: Not applicable.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable.
- Adjudication method for the test set: Not applicable.
- Multi-reader multi-case (MRMC) comparative effectiveness study: Not applicable.
- Standalone (i.e., algorithm only without human-in-the-loop performance) study: Not applicable.
- Type of ground truth used: Not applicable.
- Sample size for the training set: Not applicable.
- How the ground truth for the training set was established: Not applicable.
§ 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.