(148 days)
The GMK® Total Knee System is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components.
This knee replacement system is indicated in the following cases:
- · Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis.
- · Avascular necrosis of femoral condyle.
- · Post traumatic loss of joint configuration.
- · Primary implantation failure.
The tibial augments are to be attached to the tibial baseplate with both the fixing cylinders and bone cement.
In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components.
This modification to the original Medacta GMK® (Global Medacta Knee) Total Knee System is a line extension to include the GMK® Revision SC (Semiconstrained) liners. The GMK® Revision SC liners work with components from the GMK® Total Knee System and from the GMK® Revision, a previously cleared Special 510(k) to the GMK® Total Knee System.
The GMK® Revision SC Liners, the subject of this 510(k), are a set of tibial inserts which work with the GMK® Revision femoral PS components and the GMK® tibial baseplates. These liners provide the surgeon with an additional option. The GMK® Revision SC Liners are offered in six sizes with seven thicknesses from 10 mm to 26 mm. The GMK® Revision SC Liners are attached to the GMK® tibial baseplates of the same size from the GMK® Total Knee System using a support peg made of CoCrMo. The device is used to replace the articular surface of the tibial plateau in the knee joint by limiting the movement of the prosthetic femoral component in translation and rotation. The GMK® Revision SC Liners attached to the GMK® tibial baseplates can also be combined with an extension stem, an offset connector and tibial wedges.
The provided text describes a 510(k) submission for a medical device (GMK® Total Knee System- Revision Semi-Constrained Liners), focusing on proving substantial equivalence to a predicate device rather than a standalone performance study with a defined acceptance criteria for diagnostic accuracy. Therefore, several of the requested sections (e.g., sample size for test/training sets, ground truth establishment, expert qualifications, MRMC study) are not applicable or cannot be extracted from this document, as they relate to studies typically conducted for devices that perform a measurement or diagnostic function.
However, I can provide information based on the performance testing conducted to demonstrate substantial equivalence.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Static & Dynamic Testing (A/P Direction) | Based on standards, FDA guidance, and comparison to predicate device system. (Details not specified, assumed to be within acceptable ranges for knee implants) | Met all acceptance criteria. |
| Static Testing (M/L Direction) | Based on standards, FDA guidance, and comparison to predicate device system. (Details not specified) | Met all acceptance criteria. |
| Pullout Testing (SC liner to tibial baseplate) | Based on standards, FDA guidance, and comparison to predicate device system. (Details not specified) | Met all acceptance criteria. |
| Rotary/Laxity Testing | Based on standards, FDA guidance, and comparison to predicate device system. (Details not specified) | Met all acceptance criteria. |
| Varus/Valgus Testing | Based on standards, FDA guidance, and comparison to predicate device system. (Details not specified) | Met all acceptance criteria. |
| Range of Motion | Comparable to predicate device. | Evaluated in comparison to predicate; testing met acceptance criteria. |
| Contact Area | Comparable to predicate device. | Evaluated in comparison to predicate; testing met acceptance criteria. |
2. Sample size used for the test set and the data provenance
- Sample Size: The document states "The testing was conducted on the worst case component size and option/design based on engineering analysis." This implies a limited physical sample size, likely representative units for specific configurations, rather than a large statistical sample of clinical data.
- Data Provenance: The testing was conducted by the manufacturer (Medacta International SA), likely in their own or contracted testing facilities. This is a retrospective analysis of the device's mechanical and functional properties against established engineering and regulatory benchmarks, not clinical data provenance.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. This document describes mechanical performance testing of a knee implant component, not a diagnostic device requiring expert interpretation for ground truth.
4. Adjudication method for the test set
Not applicable. This is not a study requiring adjudication of expert opinions. The "ground truth" for these tests would be the established engineering standards and design specifications.
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
Not applicable. This is a medical device (implantable knee component), not an AI-assisted diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. This is a medical device (implantable knee component), not an algorithm. The "standalone" performance here refers to the device's mechanical integrity and function.
7. The type of ground truth used
The ground truth used for this type of submission is based on:
- Established standards (e.g., ISO, ASTM for medical devices, though not explicitly stated which ones).
- FDA guidance documents for knee prostheses.
- Comparison to the predicate device system (GMK® Total Knee System, K090988), meaning the performance of the new device should be within the established parameters or comparable to the predicate.
- Design specifications and risk analysis outcomes defined by the manufacturer.
8. The sample size for the training set
Not applicable. This is not a machine learning or AI device.
9. How the ground truth for the training set was established
Not applicable.
§ 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.