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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."

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."

• 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.

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Reaxon® Plus is indicated for repair of peripheral nerve discontinuities up to 10 mm and 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 up to 10mm and where gap closure can be achieved by flexion of the extremity.

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.

The provided text is a 510(k) Summary for the Reaxon® Plus device, a nerve cuff. This type of document is for regulatory purposes to demonstrate substantial equivalence to a predicate device, not typically for reporting on a clinical effectiveness study with acceptance criteria in the way medical AI devices often do (e.g., sensitivity, specificity for diagnostic tasks).

Therefore, some of the requested information, specifically related to "acceptance criteria" for diagnostic performance, "sample size for the test set," "number of experts," "adjudication method," "multi-reader multi-case (MRMC) comparative effectiveness study," "standalone performance," and "training set details" are not applicable or explicitly stated in this document because it outlines a series of biocompatibility and performance bench tests for a physical medical implant.

However, I can extract the "acceptance criteria" and "reported device performance" from the various tests conducted to demonstrate the safety and effectiveness of the Reaxon® Plus. These criteria are more about meeting safety standards and functional requirements compared to the predicate device.

Here's a breakdown of the available information:

1. Table of Acceptance Criteria and Reported Device Performance:

2. Sample Size Used for the Test Set and Data Provenance:

• Cytotoxicity: Triplicate monolayers of L-929 mouse fibroblast cells.
• Acute Systemic Toxicity: Five mice.
• Sensitization: Ten test guinea pigs per extract, five control guinea pigs per vehicle.
• Irritation/Intracutaneous Reactivity: Three rabbits, five separate injection sites on each.
• Subacute Toxicity: Animals (rats) – specific number not provided but states "animals were observed."
• Implantation (Local Tissue Response): Animals (rabbits) – specific number not provided.
• Pyrogenicity: Three rabbits.
• Genotoxicity (Bacterial Reverse Mutation): Triplicate plates for each of five tester strains (Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2uvrA) with and without metabolic activation. Parallel testing with negative and positive controls.
• Genotoxicity (Mouse Lymphoma Assay): Duplicate tests for each test extract and negative control.
• Genotoxicity (Mouse Peripheral Blood Micronucleus Study): Twelve mice per test article extract (six per sex), six animals per sex for negative control, and six animals per sex for positive control.
• Long-term Implantation: Wistar rats, 10 mm rat sciatic nerve defect. Number of animals not specified, but various implantation times (12, 24, 50, 74/77 weeks) indicate a longitudinal study.
• Dimensional/Visual Inspection: Reaxon® Plus tubes (number not specified).
• Suture Retention Strength: Reaxon® Plus tubes (number not specified).
• Compression and Rebound Analysis: 1 cm of each tube (number not specified).

Data Provenance: The studies are primarily in-vitro (cell cultures) and animal studies (mice, guinea pigs, rabbits, rats). The studies appear to be prospective, designed specifically for this regulatory submission. Country of origin not explicitly stated but Medovent GmbH is based in Germany.

3. Number of Experts Used to Establish Ground Truth and Qualifications:

Not applicable in the context of these biocompatibility and bench tests. The "ground truth" here is based on objective laboratory measurements, animal observations, and histological examinations by trained personnel.

4. Adjudication Method:

Not applicable. These are laboratory and animal studies with objective measurements, not subjective evaluations requiring adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No, this type of study was not conducted as it is not relevant for a physical implant like a nerve cuff. This study design is typically for diagnostic imaging devices where human interpretation is involved.

6. Standalone Performance Study:

Yes, all the listed studies represent standalone performance evaluations of the Reaxon® Plus device itself, often compared against established negative/positive controls or, for mechanical aspects, against its predicate device (NeuraGen® Nerve Guide). The "standalone" here refers to the device's intrinsic properties and biological interactions as measured in a controlled setting, not an algorithm's performance.

7. Type of Ground Truth Used:

The ground truth for these studies is based on:

• In-vitro measurements: (e.g., cell morphology, reactivity grades for cytotoxicity, revertant counts for genotoxicity)
• Animal observations and clinical signs: (e.g., systemic toxicity, dermal reactions, body weight, pyrogenic response, general health)
• Histopathology/Microscopic evaluation: (e.g., tissue response at implantation sites, cellular degeneration, macrophage presence, fibrotic layer thickness)
• Mechanical and Physical Measurements: (e.g., dimensions, force required for suture retention, compression force, rebound)

8. Sample Size for the Training Set:

Not applicable. This is not an AI/machine learning device that would have a training set.

9. How the Ground Truth for the Training Set Was Established:

Not applicable.

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