(207 days)
Components in the Genesis, Genesis II, and Profix Knee Systems are indicated for: 1) Rheumatoid arthritis; 2) Post-traumatic arthritis, osteoarthritis, or degenerative arthritis in older patients whose age, weight, and activity level are compatible with an adequate long-term result. 3) Failed osteotomies, unicompartmental replacement, or total knee replacement. 4) The posterior stabilized knee system is designed for use in patients in primary and revision surgery, where the anterior and posterior cruciate ligaments are incompetent and the collateral ligaments remain intact. 5) The constrained knee system is designed for use in patients in primary and revision surgeries, where the posterior cruciate ligament and one or both of the collateral ligaments (i.e. medial collateral and/or lateral collateral ligaments) are absent or incompetent. The devices that are the subject of this premarket notification are intended for cemented use only and are for single use only. The Orthopaedic Division of Smith & Nephew, Inc. will utilize the VHP sterilization process to terminally sterilize all orthopaedic implant components manufactured from UHMWPE material in the Genesis Knee System, the Genesis II Knee System, and the Profix Knee System (tibial articular inserts, all polyethylene tibial bases, patellae, and flex-lok pegs).
There have been no changes in indications for use, design, or material property changes to any Geness, Genesis II, or Profix Knee System UHMWPE components that will be sterilized using the VHP® process. The VHP sterilization process uses hydrogen peroxide (H2O2) vapor for sterilization Genesis Knee System, Genesis II Knee System, and Profix Knee System components (tibial articular inserts, all polyethylene tibial bases, patellar, and flex-lok pegs) manufactured from UHMWPE using the Century SL VHP® Sterilizer. Sterilization is achieved by a series of H2O2 gas injections at deep vacuum set points. Aeration of the medical devices after sterilization is conducted by a series of chamber evacuations.
Acceptance Criteria and Study for Smith & Nephew UHMWPE Components Sterilization
This document describes the acceptance criteria and the study that demonstrates the Smith & Nephew UHMWPE Components of the Genesis, Genesis II, and Profix Knee Systems meet these criteria after being sterilized with the VHP® Sterilization Process.
1. Acceptance Criteria and Reported Device Performance
The core acceptance criterion for the VHP® sterilization process is its ability to achieve a Sterility Assurance Level (SAL) of at least 10⁻⁶ for the UHMWPE components.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Microbicidal effectiveness of vaporized hydrogen peroxide. | Test results demonstrated the VHP® sterilization process is capable of terminally sterilizing UHMWPE orthopaedic implants. (Implies microbicidal effectiveness). |
| No detrimental effects of the VHP sterilization cycle on UHMWPE materials and product packaging. | The effects of the VHP sterilization cycle on UHMWPE materials in which the product is packaged were evaluated and found acceptable (Implies no detrimental effects). |
| Process validation to demonstrate effectiveness and reproducibility, resulting in a SAL of at least 10⁻⁶. | Process validation efforts demonstrated that the VHP® sterilization process is effective and reproducible, resulting in a SAL of at least 10⁻⁶. The VHP sterilization process was also demonstrated to be safe, reproducible, predictable, and effective in sterilizing UHMWPE orthopaedic implants packaged and sealed in Tyvek Mylar pouches. |
2. Sample Size and Data Provenance
The document does not explicitly state the specific sample sizes used for the "numerous tests" conducted. It also does not specify the country of origin of the data or whether the studies were retrospective or prospective.
3. Number of Experts and Qualifications for Ground Truth
The document does not mention the use of experts to establish ground truth for a test set in the context of validating the sterilization process. The ground truth for sterilization is typically established through recognized microbiological methods and standards, rather than expert interpretation of medical images or clinical outcomes.
4. Adjudication Method
Not applicable. Adjudication methods are typically used in studies involving subjective assessment (e.g., medical image interpretation) where multiple readers might have differing opinions. For sterilization validation, the results are generally objective and based on established laboratory protocols.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This type of study is relevant for evaluating the impact of AI on human reader performance in diagnostic tasks, not for validating a sterilization process.
6. Standalone Performance (Algorithm Only)
This study focuses on the standalone performance of the VHP® sterilization process itself, without human intervention during the sterilization cycle. The performance metrics reported directly reflect the capabilities of the process to achieve sterility. The statement, "Test results demonstrated that the VHP® sterilization process is capable of terminally sterilizing UHMWPE orthopaedic implants and verifies achievement of a SAL of 10," confirms its standalone capability.
7. Type of Ground Truth Used
The ground truth used for this study is based on microbiological efficacy testing and sterility assurance level (SAL) determination. This involves standardized methods to challenge the sterilization process with known microbial loads and evaluate its ability to eliminate them to a specified probability (10⁻⁶ in this case). This is an objective, science-based ground truth.
8. Sample Size for Training Set
Not applicable. This is not a study involving machine learning or AI where a "training set" would be used. The "training" for the VHP® sterilization process refers to the development and optimization of the sterilization cycle parameters, which is a process engineering activity rather than an AI training process.
9. How Ground Truth for Training Set Was Established
Not applicable, as there is no "training set" in the AI sense for this type of study. The development of the VHP® sterilization process and its parameters would have relied on iterative testing and validation using microbiological indicators and standard sterility testing protocols to ensure efficacy and reproducibility. These protocols establish the "ground truth" for effective sterilization parameters.
§ 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.