(332 days)
The Unity Total Knee System is intended for use in total knee arthroplasty in skeletally mature patients, to provide increased mobility and reduce pain by replacing the damaged knee joint articulation where there is evidence of sufficient sound bone to seat and support the components.
General total knee arthroplasty indications include:
- Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatoid arthritis or post-traumatic arthritis
- Post-traumatic loss of knee joint configuration and function
- Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function
- Revision of previous unsuccessful knee replacement or other procedure, where soft tissue stability is adequate
- Fracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniques
- The posterior stabilized variant is also indicated for PCL instability requiring implant bearing surface geometries with increased anterior-posterior constraint and absent or non-functioning posterior cruciate ligament
The Unity Total Knee System is indicated for cemented, single use only.
The Corin Unity Knee System is a fixed bearing total knee replacement system that consists of a femoral component, tibial insert, tibial tray and all-polyethylene patellar component for use in primary total knee arthroplasty. The Unity Knee System is provided in two variants, cruciate retaining (CR) and posterior stabilized (PS). The Unity CR Total Knee System is intended to accommodate the posterior cruciate ligament (PCL) if it is present. The Unity posterior stabilized variant is utilized when total knee replacement is indicated, and the posterior cruciate ligament is non-functioning or absent, resulting in joint instability. The Unity system patellar component is optional and is used in situations where replacement of the articular surface of the patella is required. The system also provides augment components including femoral wedges, tibial wedges, a short keel extension and stem extensions with offset connections.
The provided document describes the Unity™ Total Knee System, a medical device for knee arthroplasty. It states that "Clinical testing was not necessary to determine substantial equivalence between the Unity Total Knee System and the predicate devices." Therefore, the document does not contain information regarding acceptance criteria, reported device performance from a test set, sample sizes, expert involvement, adjudication methods, MRMC studies, standalone performance, or ground truth establishment relevant to an AI/ML-based device.
Instead, the document focuses on non-clinical testing to establish substantial equivalence to predicate devices. This type of evaluation is common for mechanical medical devices, where performance is assessed through bench testing rather than clinical trials with human subjects interacting with software.
Here's a breakdown of what the document does provide regarding the device's evaluation, as per your request related to acceptance criteria, but reinterpreted for a mechanical device:
1. A table of acceptance criteria and the reported device performance:
| Acceptance Criteria (from ASTM F2083) | Reported Device Performance |
|---|---|
| Component function for: | |
| - Femoral component | Expected to be safe and effective (based on testing) |
| - Tibial tray | Expected to be safe and effective (based on testing) |
| - Tibial insert | Expected to be safe and effective (based on testing) |
| Specific tests performed: | |
| - Fatigue | Results support safety and effectiveness |
| - Endurance | Results support safety and effectiveness |
| - Deformation | Results support safety and effectiveness |
| - Contact area | Results support safety and effectiveness |
| - Contact pressure | Results support safety and effectiveness |
| - Range of motion | Results support safety and effectiveness |
| - Constraint | Results support safety and effectiveness |
| - Wear testing of UHMWPE tibial insert | Results support safety and effectiveness |
| - Integrity of connecting mechanisms (static and dynamic shear, bending, mechanical stop, disassociation) | Results support safety and effectiveness |
Explanation: The "acceptance criteria" here are implied by adherence to industry standards, specifically ASTM F2083, which outlines specifications for total knee prostheses. The "reported device performance" is a general statement that the device met these criteria, thus deeming it "safe and effective for the proposed indications and substantially equivalent to the predicate devices."
2. Sample size used for the test set and the data provenance:
- Sample Size: Not applicable in the context of clinical data for AI/ML. For mechanical bench testing, the "sample size" would refer to the number of device components tested (e.g., number of femoral components, tibial trays, inserts). This information is not specified in the provided text, but it would typically be defined within the test protocols conforming to ASTM F2083.
- Data Provenance: Not applicable in the context of clinical data. The tests were performed "in accordance with ASTM F2083 Standard Specification for Total Knee Prosthesis." This implies controlled laboratory conditions for mechanical testing rather than patient data collection.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable as the evaluation was based on mechanical bench testing against engineering standards, not expert interpretation of clinical data.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable as the evaluation was based on mechanical bench testing against engineering standards, not expert adjudication of clinical findings.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No. This device is a mechanical total knee system, not an AI/ML diagnostic or assistive tool. Therefore, a MRMC study for AI assistance is not relevant to its evaluation.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No. This device is a mechanical total knee system.
7. The type of ground truth used:
- Engineering Standards and Specifications: The "ground truth" for this device's performance is established by the requirements and test methods outlined in ASTM F2083 Standard Specification for Total Knee Prosthesis. Compliance with these established industry standards (e.g., specific deflection limits, fatigue life, wear rates, constraint magnitudes) serves as the basis for determining the device's mechanical integrity and functional performance.
8. The sample size for the training set:
- Not applicable. This device is a mechanical knee prosthesis, not an AI/ML system that requires a "training set."
9. How the ground truth for the training set was established:
- Not applicable. This device is a mechanical knee prosthesis.
§ 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.