(90 days)
The Ascension® MUH is intended for replacement of the distal radioulnar joint:
Replacement of the distal ulnar head for rheumatoid, degenerative, or post-traumatic arthritis presenting the following:
- Pain and weakness of the wrist joint not improved by conservative treatment .
- Instability of the ulnar head with x-ray evidence of dorsal subluxation and erosive . changes
- Failed ulnar head resection .
The Ascension® MUH implant is a single-use, two-component, modular prosthesis designed for replacement of the ulnar head. Components will be available in three head sizes, and nine stem sizes which are assembled by means of a taper connection. Device components are made from cobalt chromium alloy meeting ASTM F1537 and titanium Ti6A14V ELI meeting ASTM F136, the same materials used to fabricate other ulnar head prostheses that have market clearance for sale in the United States.
The provided text is a 510(k) Summary for the Ascension® MUH ulnar head prosthesis, which is a medical device. This document focuses on demonstrating substantial equivalence to a predicate device rather than presenting a study proving the device meets specific performance acceptance criteria through clinical or analytical trials.
Therefore, the document does not contain the information requested regarding acceptance criteria and a study proving the device meets them, as typically understood for a novel device. The "study" here is a comparison to a legally marketed predicate device.
Here's an analysis of why the requested information is absent based on the provided text:
- Acceptance Criteria and Reported Device Performance: These are not provided because the submission is for substantial equivalence to a predicate device, not for demonstrating performance against defined metrics for a novel technology. The "performance" being assessed is the equivalent design, materials, and intended use to the predicate.
- Sample size and data provenance: No test set or data provenance is mentioned because this is a medical device comparison submission, not a study involving patient data or a test set in the conventional sense of a clinical trial or algorithm validation.
- Number of experts and qualifications: Not applicable. Ground truth establishment is not relevant for this type of submission focused on device comparison rather than diagnostic accuracy or clinical outcomes.
- Adjudication method: Not applicable.
- Multi Reader Multi Case (MRMC) comparative effectiveness study: Not applicable. This type of study is relevant for diagnostic devices or AI algorithms that assist human readers, not for a prosthetic device submission based on substantial equivalence.
- Standalone (algorithm-only) performance: Not applicable, as this is a physical prosthetic device, not an algorithm.
- Type of ground truth used: Not applicable, as there's no diagnostic or predictive component being evaluated.
- Sample size for the training set: Not applicable, as this is a physical medical device, not an AI model.
- How the ground truth for the training set was established: Not applicable.
Summary of Device Comparison (used as the "study" for substantial equivalence):
The "study" presented is a comparison of features between the Ascension® MUH implant and the predicate device, Avanta Orthopaedics, Inc., Ulnar Head Implant (K010786).
Acceptance Criteria (Implicit for Substantial Equivalence):
The implicit acceptance criteria for substantial equivalence, as demonstrated by the comparison table, are that the subject device (Ascension® MUH) must have:
- Same Indications For Use: Confirmed, as stated in the text.
- Same/Similar Design: Confirmed (two-piece modular implant, taper connection, stem in medullary canal, hemi articulation).
- Same/Similar Materials: Confirmed (cobalt chromium for head, titanium for stem – a different grade of titanium for the stem, but considered acceptable for substantial equivalence to CpTi).
- Same/Similar Performance Characteristics: Implied by the above similarities and the lack of new questions of safety or effectiveness.
- No new questions of safety or effectiveness: Implied by the FDA's determination of substantial equivalence.
Reported Device "Performance" (Comparison to Predicate):
Below is a table summarizing the comparison, which serves as the "proof" for substantial equivalence.
| Comparison Feature | Ascension® MUH (Subject Device) | Avanta Ulnar Head Implant (Predicate Device) |
|---|---|---|
| Design | Two-piece modular implant | Two-piece modular implant |
| Material (Head) | ASTM F1537 cobalt chromium | ASTM F1537 cobalt chromium |
| Material (Stem) | ASTM F136 Ti6Al4V ELI | CpTi |
| Assembly | Taper connection | Taper connection |
| Fixation | Stem in medullary canal | Stem in medullary canal |
| Articulation | Hemi | Hemi |
| Use | Single use only, surgical implantation longer than 30 days | Single use only, surgical implantation longer than 30 days |
| Sterilization by user | Resterilization of device is not recommended. | Resterilization of device is not recommended. |
| Packaging | Double barrier assembly in paperboard box | Double barrier assembly in paperboard box |
| Accessories | Sterilizable instrumentation available separately | Sterilizable instrumentation available separately |
| Stem surface finish | Roughened | Roughened |
| Available sizes | Three heads (3 diameters), Nine stems | Three heads (3 diameters), Six stems |
| Indications for Use | Identical to predicate device | See "Indications For Use" section |
| Functional Equivalence | Functionally identical | (Implied) |
| Sizing | Comparably sized (more stem options) | (Implied) |
Conclusion from the "Study":
The 510(k) summary explicitly states: "The Ascension® MUH is functionally identical, comparably sized, and has a similar design as compared to the Avanta Ulnar Head Implant. Individual components for the subject and predicate device are provided sterile in individual packages. The Ascension® MUH shares identical indications for use with the predicate device, and is fabricated from the same material as the predicate device. Therefore, the Ascension® MUH is substantially equivalent to the predicate device."
In summary, the provided document does not describe a performance study with acceptance criteria in the typical sense of evaluating a novel device's efficacy or safety against specific metrics. Instead, it presents a comparison to a predicate device to establish substantial equivalence based on design, materials, and intended use.
§ 888.3810 Wrist joint ulnar (hemi-wrist) polymer prosthesis.
(a)
Identification. A wrist joint ulnar (hemi-wrist) polymer prosthesis is a mushroom-shaped device made of a medical grade silicone elastomer or ultra-high molecular weight polyethylene intended to be implanted into the intramedullary canal of the bone and held in place by a suture. Its purpose is to cover the resected end of the distal ulna to control bone overgrowth and to provide an articular surface for the radius and carpus.(b)
Classification. Class II.