(89 days)
Reaxon Plus is indicated for repair of peripheral nerve discontinuities where gap closure can be achieved by flexion of the extremity.
Reaxon® Plus is a flexible and transparent chitosan based implant designed for repair of peripheral nerve discontinuities.
Reaxon® Plus was developed to provide a protective environment for axonal growth across a nerve gap. When hydrated, Reaxon® Plus is an easy to handle, soft, pliable, transparent chitosan tube. Reaxon® Plus is provided sterile, non-pyrogenic, for single use in double blister packages in a variety of sizes as shown below.
Here's an analysis of the provided text to extract information regarding acceptance criteria and the study proving the device meets them:
Disclaimer: The provided document is a 510(k) summary for a medical device (Reaxon® Plus, a nerve guide). Unlike a typical clinical trial report for an AI/ML diagnostic, this document focuses primarily on demonstrating substantial equivalence to a predicate device, largely through biocompatibility and mechanical testing, and then references a separate clinical trial for performance. Therefore, many of the typical acceptance criteria and study details for an AI/ML algorithm (e.g., algorithm-only performance, MRMC studies, detailed ground truth establishment for a diagnostic output) are not directly applicable or fully detailed in this type of submission. This response will extract what is present and note where information is not available due to the nature of the document.
Device Name: Reaxon® Plus (Nerve Guide)
Predicate Device: NeuraGen® Nerve Guide
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a nerve guide (physical implant) and not an AI/ML diagnostic, the "acceptance criteria" are related to biocompatibility, mechanical properties, and clinical performance for nerve regeneration, rather than diagnostic metrics like sensitivity/specificity. The document states that the new device has "similar safety and effectiveness as its predicate device."
| Acceptance Criteria Category | Acceptance Criteria (General) | Reported Device Performance (Reaxon® Plus) |
|---|---|---|
| Biocompatibility (ISO 10993) | No toxicity, irritation, sensitization, genotoxicity, or pyrogenicity; suitable local tissue response. | Cytotoxicity: No cytotoxicity (Grade 0.25N and re-open following removal of compressive forces (specific rebound measurement implied satisfactory). |
| Long-Term Stability/Degradation (Animal) | Slow, mild degradation; good stability; mild tissue response. | Slow degradation process; very mild tissue response. Low number of activated macrophages, good stability, marginal signs of degradation until 50 weeks, first significant macroscopic signs at 74/77 weeks. Stable biological tissue response at 3 months, further decreasing macrophages and thinner fibrotic layer. |
| Clinical Performance (Nerve Regeneration) | Achieve meaningful nerve regeneration for peripheral nerve discontinuities, including larger gaps. | Demonstrated nerve regeneration in finger nerve defects, including gaps up to 26 mm. |
| Static 2-PD: 50% of Reaxon® group achieved meaningful response (grade 2 or 3) at 6 months vs. 20% of control (autograft). | ||
| Moving 2-PD: 50% of Reaxon® group and 60% of control showed response (grade 2 or 3) at 6 months; 33% of Reaxon® had best score (grade 3) vs. 20% of control. | ||
| Semmes-Weinstein Monofilaments: 33% of Reaxon® group vs. 60% of control achieved normal/diminished perception of light touch at 6 months. No Reaxon® patients showed no sensation (grade 0), while 20% of control did. | ||
| Pain/Safety: Comparable pain/satisfaction/discomfort. 4 AE in test group, 2 in control; mostly moderate. One AE (wound dehiscence) in test group related to device (moderate severity). |
Note on "Acceptance Criteria": For the clinical performance aspect, the document doesn't define strict quantitative acceptance criteria (e.g., "s2-PD must be X or better in Y% of patients"). Instead, it compares the Reaxon® Plus (referred to as "Reaxon" in the clinical evaluation section) to the "gold standard autologous nerve grafting" and concludes that Reaxon® could provide faster nerve regeneration and showed positive results even for larger than 10 mm gaps. The "acceptance" is implicitly tied to demonstrating comparable or superior performance to the predicate/gold standard.
2. Sample Size Used for the Test Set and Data Provenance
- Biocompatibility/Mechanical Tests: Sample sizes are not explicitly stated for individual tests (e.g., how many samples were tested for suture retention), but methodologies describe using "triplicate monolayers," "group of five animals," "ten test guinea pigs," "three animals," etc.
- Long-term Animal Implantation: Wistar rats (specific number of animals or implants not given, though "after different implantation times (12, 24, 50 and 74/77 weeks)" implies multiple animals over time).
- Clinical Evaluation:
- Test Set Sample Size: 11 subjects (for the interim report). This small sample included 6 patients in the Reaxon® group and 5 patients in the Autograft (control) group.
- Data Provenance: The clinical trial used for the clinical evaluation of Reaxon® (which is stated to be "exactly the same nerve guide as Reaxon® Plus") was done in Europe (as suggested by the European approval mentioned). It appears to be a prospective clinical study, as it describes a "first interim clinical study report" with follow-up points at 3 and 6 months after inclusion of the first subject (inclusion of first subject until 31.12.2016).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- This question is not directly applicable to this device submission. For a physical implant like a nerve guide, "ground truth" for clinical performance is established by objective measurements of nerve function (e.g., 2-point discrimination, monofilament tests) and clinical outcomes, not expert consensus on image interpretation.
- The clinical trial collected objective measures of nerve regeneration and patient-reported outcomes.
4. Adjudication Method for the Test Set
- Not applicable in the typical sense for AI/ML diagnostics. Clinical trial data typically involves data collection by trained personnel at clinical sites following a protocol. It doesn't involve "adjudication" in the sense of resolving conflicting expert opinions on a diagnostic output. Data consistency and quality are typically managed through standard clinical trial monitoring and quality control processes.
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, an MRMC study was not done. This is a physical implant, not an AI-assisted diagnostic tool for human readers. The clinical study was a direct comparison of the device (Reaxon®) to traditional autografting for nerve repair.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
- Not applicable. This device is a physical nerve guide implant. There is no algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
-
Clinical Outcomes Data and Objective Measurements: For the clinical evaluation, the "ground truth" for nerve regeneration and function was established through:
- Static 2-point discrimination (s2-PD) measurements.
- Moving 2-point discrimination (m2-PD) measurements.
- Semmes-Weinstein monofilament test results (for sensory reinnervation).
- Pain assessment.
- Assessment of adverse events (safety).
- Comparison to the "current gold standard autologous nerve grafting."
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Bench and Animal Testing: For the non-clinical tests, the "ground truth" was derived from standard laboratory and animal model evaluations based on established scientific methods and relevant ISO standards (e.g., ISO 10993 for biocompatibility) and direct physical measurements for mechanical properties.
8. The sample size for the training set
- Not applicable. This is not an AI/ML device that requires a training set. The various pre-clinical tests (biocompatibility, mechanical) demonstrate performance of the manufactured device.
9. How the ground truth for the training set was established
- Not applicable. As there is no training set for an AI/ML algorithm, this question is not relevant. The "ground truth" for the device's design and performance claims is rooted in established scientific principles, ISO standards, and the results of the described pre-clinical and clinical studies.
§ 882.5275 Nerve cuff.
(a)
Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors).(b)
Classification. Class II (performance standards).