(162 days)
The NovoKnee 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, 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. The NovoKnee Total Knee System 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. The NovoKnee Total Knee System is designed for cemented use only.
The NovoKnee Total Knee System is of the fixed bearing type with a posterior stabilized design. It is a Patellofemorotibia, polymer/metal/polymer, semi-constrained, cemented knee prosthesis, that consists of a femoral component, tibial tray and patellar component. The femoral component articulates with the tibial insert component. The underside of the tibial insert component is flat and "snaps" into the tibial baseplate component. Each femoral component has the same intercondylar distance and radius of curvature. Each tibial insert component is complimentarily shaped to conform to the femoral components. This allows any size femoral component to be matched with any size tibial component. The dome shape of each UHMWPE patellar component provides excellent contact with the femoral component and evenly distributes stresses. The dome and sombrero shape of each UHMWPE patellar component provides contact with the femoral component.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Fatigue performance of the tibial tray | Equivalent to the U2 Total Knee System |
| Interlock mechanism strength (tibial tray and tibial insert) | Equivalent to the U2 Total Knee System |
| Shear fatigue strength of the tibial insert post | Equivalent to the U2 Total Knee System |
| Femoral/tibial insert contact pressures and areas | Equivalent to the U2 Total Knee System |
| Lateral subluxation of patellar component | Equivalent to the U2 Total Knee System |
| Range of motion performance | Equivalent to the U2 Total Knee System |
| Capable of withstanding expected in vivo loading without failure | Equivalent to the U2 Total Knee System |
2. Sample Size Used for the Test Set and Data Provenance:
The document does not explicitly state the sample sizes used for the mechanical testing (test set) or the data provenance. The studies were likely laboratory-based mechanical performance tests rather than clinical trials with human subjects.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts:
Not applicable. The ground truth for this type of mechanical device testing is established through engineering and biomechanical standards and measurements, not expert consensus as would be used in diagnostic studies.
4. Adjudication Method for the Test Set:
Not applicable. This was mechanical performance testing against established engineering standards and comparison to a predicate device, not an adjudication process involving human reviewers.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
No, an MRMC comparative effectiveness study was not done. This device is a total knee replacement system, and the studies performed were mechanical performance tests, not studies involving human readers and interpretations of cases.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
Not applicable. This device is a physical knee prosthesis, not an algorithm or AI system. The performance testing was for the mechanical integrity and function of the device itself.
7. The Type of Ground Truth Used:
The ground truth used was based on engineering standards and direct physical measurements of the device's mechanical properties and performance. This includes metrics like fatigue life, strength, contact pressures, and range of motion, compared against the known performance of the predicate device (U2 Total Knee System) which has established safety and effectiveness.
8. The Sample Size for the Training Set:
Not applicable. This mechanical device did not involve a "training set" in the context of typical AI/ML studies. The manufacturing and design process would involve iterative testing and refinement, but not a formally defined "training set" as understood in machine learning.
9. How the Ground Truth for the Training Set Was Established:
Not applicable, as there was no "training set" in the context of AI/ML. For the design and development of the physical device, ground truth would be established through engineering calculations, material science properties, and iterative physical prototyping and testing against design specifications and established biomechanical principles.
§ 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.