(29 days)
The patient should be skeletally mature to receive a knee replacement. Patients should have adequate bone stock and size to support and accept the prosthesis.
The patient's need for knee replacement should be due to one or more of the following conditions:
- Non-inflammatory degenerative joint disease including osteoarthritis, or avascular necrosis.
- Inflammatory degenerative joint disease including rheumatoid arthritis.
- Functional deformity such as varus, valgus or flexion deformities.
- Revision procedures where other treatments or devices have failed.
- Fractures that are unmanageable using other techniques.
The World Knee replacement system is indicated for cemented fixation with bone cement (PMMA) only.
The World Knee system is a modular knee system consisting of a femoral component, meniscal insert, a patella and a tibial baseplate. The femoral component and tibial baseplate components are manufactured from cast cobalt chromium alloy and are intended for use with bone cement. The modular femoral peg is manufactured from wrought cobalt chromium alloy. The femoral component and meniscal inserts are available as posterior stabilised or cruciate retaining variants. Cruciate retaining meniscal inserts are available as standard or ultracongruent designs. All variants of the meniscal insert and patella are manufactured from UHMWPE.
Here's an analysis of the provided text regarding the acceptance criteria and study for the World Knee System, formatted to address your specific questions.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What was measured) | Reported Device Performance |
|---|---|
| Performance relative to predicate device | Performance is "equal or better than the predicate device" |
| Adequacy for anticipated in-vivo use | Confirmed "adequate for anticipated in-vivo use" |
| Substantial equivalence to predicate device | Claimed substantial equivalence based on intended use, indications for use, materials, and similar design. Similarities also stated for manufacturing process, geometry, fundamental design, body contact, and sterilization process. |
2. Sample Size Used for the Test Set and Data Provenance
The provided text does not contain information on a test set sample size or data provenance (e.g., country of origin, retrospective/prospective) related to clinical or human-use testing. The "Performance Testing" section states "Engineering evaluations were conducted," suggesting in vitro or simulation-based testing, not human subject data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This information is not applicable based on the provided text. The performance testing was described as "Engineering evaluations," implying a lack of ground truth established by medical experts for a clinical test set.
4. Adjudication Method for the Test Set
This information is not applicable as the text does not describe a clinical test set requiring expert adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, and Effect Size
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted or described in the provided text. The document focuses on engineering evaluations to demonstrate equivalence to a predicate device, not on human reader performance with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
The device is a knee prosthesis, not an algorithm. Therefore, the concept of "standalone (algorithm only)" performance is not applicable. The performance testing refers to the physical device's characteristics and its comparison to a predicate device.
7. The Type of Ground Truth Used
The "ground truth" for the performance evaluation appears to be based on engineering standards and direct comparison of physical and material properties to the predicate device, rather than clinical outcomes, pathology, or expert consensus from human subjects. The phrase "Engineering evaluations were conducted to verify that the performance...is equal or better than the predicate device" implies a comparative engineering assessment.
8. The Sample Size for the Training Set
This information is not applicable. The "World Knee System" is a physical medical device (a knee prosthesis), not an AI algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable as the device is not an AI algorithm.
§ 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.