(124 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, 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.
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 present 510k submission is for a cruciate retaining (CR) version of the NovoKnee Total Knee System. The main predicate device (K123339) is a posterior stabilized (PS) version of the NovoKnee Total Knee System. All implant components are the same between the two versions, except for the tibial inserts and the femoral components. The posterior stabilized version has tibial inserts with posts and femoral components with cams that interact with the posts to help stabilize the knee after the posterior cruciate ligament is removed. The cruciate retaining version of the NovoKnee Total Knee System has tibial inserts and femoral components without posts or cams, allowing the posterior cruciate ligament to be "retained" and provide stability to the knee joint.
The NovoKnee Total Knee System is a Patellofemorotibia, 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 fernoral 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.
This document describes the validation of the NovoKnee Total Knee System, specifically the cruciate-retaining (CR) version, against its predicate device, a posterior-stabilized (PS) version of the same system. The study aims to demonstrate substantial equivalence, not to establish performance against specific acceptance criteria for effectiveness outcomes, but rather to show that new CR components perform comparably to previously cleared components in terms of mechanical integrity and design principles.
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not specify quantitative acceptance criteria in a typical "threshold" format for clinical performance (e.g., sensitivity, specificity, accuracy). Instead, the acceptance criterion for the performance testing is demonstrating substantial equivalence to the predicate device in specific mechanical tests. The reported device performance is that this substantial equivalence was achieved.
| Test Performed | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| 1. Femoral/Tibial Insert Contact Area Test | Substantial equivalence to predicate CR version | Test results indicate substantial equivalence to predicate. These components are the same as used in the predicate. |
| 2. Anterior Shear Test of Insert/Tray Interlocking Mechanism | Substantial equivalence to predicate CR version | Test results indicate substantial equivalence to predicate. |
| 3. Posterior Shear Test of Insert/Tray Interlocking Mechanism | Substantial equivalence to predicate CR version | Test results indicate substantial equivalence to predicate. |
| 4. Medial/Lateral Shear Test of Insert/Tray Interlocking Mechanism | Substantial equivalence to predicate CR version | Test results indicate substantial equivalence to predicate. |
Note: The text explicitly states, "All implant components are the same between the two versions, except for the tibial inserts and the femoral components." Furthermore, for the Femoral/Tibial Insert Contact Area Test, while not explicitly stated, contact area is a fundamental characteristic for knee implants, and the goal for the CR version is to demonstrate comparable contact mechanics to existing designs. The mention that "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" implies a design intent to maintain similar contact characteristics. The overarching goal is substantial equivalence, which implies comparable performance in these tests to the predicate device.
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify a "test set" in the context of patient data. The performance testing described is mechanical (bench) testing of the device components. The sample size for these mechanical tests (e.g., number of implants or constructs tested) is not provided.
The data provenance is not applicable as this is a device modification submission based on mechanical testing and design comparison, not clinical trial data involving patients.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. Ground truth for mechanical testing is established by engineering specifications and objective measurements, not expert consensus.
4. Adjudication Method for the Test Set
Not applicable, as this is mechanical testing, not a clinical study involving human assessment that would require adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This is a 510(k) submission for a medical device modification (cruciate-retaining version of a total knee system), not an AI/software as a medical device (SaMD) or diagnostic imaging product that would typically involve an MRMC study comparing human readers with and without AI assistance.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop)
No, this is not applicable. The device is a physical knee implant, not an algorithm.
7. Type of Ground Truth Used
For the mechanical performance tests, the "ground truth" implicitly used is the performance characteristics of the legally marketed predicate device (K123339, NovoKnee Total Knee System - PS version). The goal is to demonstrate that the novel CR version performs equivalently in these mechanical tests.
8. Sample Size for the Training Set
Not applicable. There is no "training set" in the context of an algorithm or machine learning for this physical device.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set.
§ 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.