(70 days)
The GMK knee prosthesis 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. 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.
The GMK Sphere Total Knee System allows for medial-pivot rotation of the knee joint and is comprised of the following components: - Femoral Component Left and Right, Sizes 1-7 Co-Cr-Mo (ISO 5832-4) - Tibial tray fixed cemented Left and Right, 4 intermediate sizes . Co-Cr-Mo (ISO 5832-4) - Tibial Insert Fixed Flex and Congruent, Left and Right, Sizes 1-6, 10mm-20mm . UHMWPE (ISO 5834 -2) Type 1, Ti6Al4V (ISO 5232-3)
The provided text does not contain detailed information about specific acceptance criteria with numerical thresholds, nor does it describe a study where a medical device's performance is measured against such criteria.
Instead, the document is a 510(k) summary for the GMK Sphere Total Knee System, which focuses on demonstrating substantial equivalence to predicate devices. This type of submission relies on showing that the new device has the same intended use and technological characteristics as a legally marketed predicate device, or that any differences do not raise new questions of safety or effectiveness.
Here's a breakdown of what the document does provide in relation to performance and equivalence:
1. Acceptance Criteria and Reported Device Performance (as inferred from the substantial equivalence claim):
The document states that "A review of the mechanical data indicates that the GMK Sphere is equivalent to devices currently cleared for use and is capable of withstanding expected in vivo loading without failure." This implies that the acceptance criteria are essentially equivalence to predicate devices in terms of mechanical performance and the ability to withstand physiological loads without failure.
| Acceptance Criteria (Inferred from Equivalence) | Reported Device Performance |
|---|---|
| Instability due to design and surface area | Equivalent to cleared predicate devices |
| Constraint measurements | Equivalent to cleared predicate devices |
| Contact pressures and areas | Equivalent to cleared predicate devices |
| Dynamic physiological loads | Capable of withstanding expected in vivo loading without failure (equivalent to predicates) |
| Modular connection | Equivalent to cleared predicate devices |
| Range of Motion (ASTM 2083) | Equivalent to cleared predicate devices |
2. Sample size used for the test set and the data provenance:
- Sample Size: Not specified. The document mentions "mechanical data" but does not detail the number of samples or specific tests performed, or the number of simulated uses, etc..
- Data Provenance: Not specified. It's likely laboratory testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
This information is not applicable and not provided. The testing described is mechanical, not involving human interpretation of data for ground truth establishment.
4. Adjudication method for the test set:
Not applicable, as it's mechanical testing.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
No, an MRMC study was not done. This type of study is typically for evaluating diagnostic devices where reader performance is a key factor. This document is for a Class II knee prosthesis.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
Not applicable. This device is a physical implant, not an algorithm.
7. The type of ground truth used:
For mechanical testing of implants, the "ground truth" is typically defined by engineering standards (e.g., ASTM standards for range of motion, fatigue life, strength) and the performance characteristics of predicate devices that have been deemed safe and effective.
8. The sample size for the training set:
Not applicable. This is not a machine learning device that requires a training set.
9. How the ground truth for the training set was established:
Not applicable.
In summary:
The provided text describes a 510(k) submission for a knee prosthesis, which focuses on demonstrating substantial equivalence to previously cleared devices through mechanical performance testing. It does not describe a study that uses acceptance criteria with specific numerical thresholds met by the device's performance in a way that would be typical for, for example, an AI/ML-driven diagnostic device. The "acceptance criteria" here are implicitly linked to the performance of the legally marketed predicate devices, and the "study" is the mechanical testing conducted and reviewed to support the equivalence claim.
§ 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.