(30 days)
Indicated for intractable pain resulting from traumatic arthritis, osteoarthritis, rheumatoid arthritis, trauma-induced osteoarthritis of the radial/carpal joint. To replace functionality of the joint due to deformity or elements stated above. The Universal Total Wrist is intended for cemented use.
The KMI Universal Total Wrist (UTW) System (both predicate and extra small) consists of the following components: the radial implant, the carpal plate implant, the carpal polymer component, and two bone screws. The system will now be offered in 4 (four) sizes: 'extra small', 'small', 'medium' and 'large'), each with 3 (three) matching polymer component sizes, which are available in yarvina thicknesses (height); standard, +1 and + 2, It is constructed of materials that have a long clinical history of proven acceptance and performance. This system is intended for use with cement and will be promoted as such in the UTW Surgical Protocol.
Here's an analysis of the provided text regarding the Universal Total Wrist System, focusing on acceptance criteria and supporting studies:
Based on the provided documents, this 510(k) submission (K030037) is a Special 510(k) Notification for a modification to an already cleared device, the Universal Total Wrist System. Specifically, it's for introducing an "extra small" size. Special 510(k)s often rely heavily on demonstrating substantial equivalence to a predicate device and may not involve extensive new clinical or performance studies in the same way a novel device might.
Therefore, the concept of "acceptance criteria" and "study proving the device meets the acceptance criteria" in the traditional sense (e.g., performance metrics with defined thresholds for a new device) is not directly applicable or explicitly detailed in these documents for the modified device. Instead, the "acceptance criteria" here are implicitly met by demonstrating substantial equivalence to the predicate device. The "study" is more accurately described as a comparison and analysis against the predicate.
Here's the breakdown of the information as requested, tailored to the context of a Special 510(k) for a size modification:
Acceptance Criteria and Device Performance (Based on Substantial Equivalence)
| Acceptance Criteria (Demonstrated Equivalence to Predicate) | Reported Device Performance (Extra Small Universal Total Wrist System) |
|---|---|
| Identical Design to predicate UTW implants (small, medium, large). | The extra small size has an identical design to the predicate Universal Total Wrist System (K961051, K020554). |
| Identical Materials to predicate UTW implants. | The extra small size is constructed of identical materials as the predicate. |
| Identical Operating Principle to predicate UTW implants (functioning as a wrist joint metal/polymer prosthesis). | The extra small size has an identical operating principle as the predicate, providing wrist joint replacement. |
| Identical Packaging and Sterilization Materials and Processes to predicate UTW implants. | The extra small size is packaged and sterilized using identical materials and processes as the predicate. |
| Intended Use consistent with predicate (replacing functionality due to intractable pain from various arthropathies). | The extra small size is indicated for the same intended use as the predicate: intractable pain from traumatic arthritis, osteoarthritis, rheumatoid arthritis, or trauma-induced osteoarthritis of the radial/carpal joint, for cemented use. |
Study Details (Comparison for Substantial Equivalence)
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Sample size used for the test set and the data provenance:
- Test Set: No clinical test set in the traditional sense is described. The "test set" for this submission consists of the engineering drawings and specifications of the "extra small" implant.
- Data Provenance: The comparison is based on the design specifications and material properties of the new "extra small" component and the previously cleared "small" (predicate) component. The provenance is internal manufacturing and design data from Kinetikos Medical, Inc. This is a retrospective comparison against an already cleared predicate device.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- No external experts were explicitly mentioned as being used to establish "ground truth" for this engineering comparison. The "ground truth" for the comparison is the design and material specifications of the predicate device, which were previously reviewed and cleared by the FDA. The manufacturer's internal engineering and quality assurance personnel would have performed the comparison.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- No adjudication method in the context of expert review is described. The comparison relies on documented specifications. The FDA's review process itself acts as an adjudication that the presented information supports substantial equivalence.
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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 implant (wrist prosthesis), not an AI-powered diagnostic tool. Therefore, an MRMC comparative effectiveness study involving human readers/AI is irrelevant and was not conducted.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- No. This is a physical medical device, not an algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The "ground truth" for this submission is the already established and FDA-cleared design, material, manufacturing, and performance characteristics of the predicate Universal Total Wrist System. The "extra small" size is demonstrating conformity to these established truths by being "identical" in all key aspects except size.
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The sample size for the training set:
- Not applicable. There is no "training set" as this is not a learning algorithm. The "training" for the predicate device would have involved a long clinical history of similar materials and designs, as explicitly stated: "It is constructed of materials that have a long clinical history of proven acceptance and performance." This refers to general knowledge about medical-grade materials, not a specific training dataset for this device.
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How the ground truth for the training set was established:
- Not applicable. As above, there's no "training set." The "ground truth" for the overall device's safety and effectiveness (as represented by the predicate) was established through previous FDA clearances based on established standards, material properties, mechanical testing, and clinical history of similar devices.
§ 888.3800 Wrist joint metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist 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 either a one-part radial component made of alloys, such as cobalt-chromium-molybdenum, with an ultra-high molecular weight polyethylene bearing surface, or a two-part radial component made of alloys and an ultra-high molecular weight polyethylene ball that is mounted on the radial component with a trunnion bearing. The metallic portion of the two-part radial component is inserted into the radius. These devices have a metacarpal component(s) made of alloys, such as cobalt-chromium-molybdenum. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.