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The Nexa bone screw system provides fixation of fractures, fusions, or osteotomies of bones of the hand and foot.

The Nexa Orthopedics bone screw system consists of screws made of Titanium (6AL-4V ELI) intended to be implanted into the bones of the foot, and hand. The screws are provided in 6 sizes. The screws are used for fixation of fractures, fusions, or osteotomies of bones of the hand and foot. The design of the Nexa bone screw system is similar in shape and size to the Wright Medical Charlotte Snap-Off Screw. No new materials arc used in the development of this implant.

This document describes a medical device submission (K053394) for the Nexa bone screw system. This is a premarket notification (510(k)), which aims to demonstrate that a new device is substantially equivalent to a legally marketed predicate device. This type of submission generally does not involve clinical studies with acceptance criteria for device performance as would be seen for new, high-risk devices.

Instead, substantial equivalence is established by comparing the new device's design, materials, indications for use, and technological characteristics to those of a predicate device. The "acceptance criteria" here are therefore about demonstrating this substantial equivalence, rather than meeting specific performance metrics from a clinical trial.

Based on the provided text, there is no study described that proves the device meets specific performance acceptance criteria in the way you might expect for a diagnostic or AI-powered device. This 510(k) is for a bone screw system, which is a physical implant, and the primary demonstration of safety and effectiveness relies on its similarity to an already approved device.

Here's an analysis based on your requested information, highlighting what is (and isn't) present in the provided text:

Description of Acceptance Criteria and Proving Device Meets Criteria (Based on Substantial Equivalence)

The "acceptance criteria" for K053394 are implicitly tied to the demonstration of substantial equivalence to the predicate device, the Wright Medical Charlotte Snap-Off Screw (K043583). The study performed is a comparison study of device characteristics. The "device performance" in this context refers to the characteristics and intended use being sufficiently similar to the predicate.

1. Table of Acceptance Criteria and Reported Device Performance

Given this is a 510(k) for a physical implant, the "acceptance criteria" are not reported as numerical performance metrics (like sensitivity, specificity, etc.) but rather as successful demonstration of similarity in key attributes to the predicate device.

Summary: The comparison table in the submission (Table 1) acts as the "study" demonstrating that the Nexa bone screw system meets the implicit acceptance criteria of substantial equivalence by showing its characteristics align with the predicate device.

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

Not applicable. This is not a study involving a "test set" of patient data in the context of diagnostic or AI performance. The "test set" here would be the physical device itself being compared to the predicate's specifications and historical performance. Data provenance similarly is not applicable as there is no patient data or clinical outcomes data presented.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts

Not applicable. Ground truth for a physical implant's design and material equivalence is established by engineering and material specifications, not expert consensus on patient cases.

4. Adjudication Method for the Test Set

Not applicable. There is no "test set" requiring adjudication in this type of submission.

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

Not applicable. This device is a physical bone screw, not an AI-powered diagnostic or assistive tool.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Not applicable. This is not an algorithm or AI device.

7. The Type of Ground Truth Used

For this 510(k) submission, the "ground truth" is primarily based on:

• Engineering specifications and material science: Verification that the materials (Titanium 6AL-4V ELI) and design (shape, sizes) of the Nexa screw meet established standards and are comparable to the predicate.
• Predicate device's established safety and effectiveness: The Charlotte Snap-Off Screw, being a legally marketed device, serves as the benchmark for what is considered safe and effective for its indicated uses.
• Regulatory definitions: Adherence to FDA regulations for Class II devices and product codes.

8. The Sample Size for the Training Set

Not applicable. There is no "training set" in the context of an AI/algorithm. For an implant like this, manufacturing quality control would involve testing samples from production batches, but this is distinct from a "training set" in AI.

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

Not applicable, as there is no training set.

In summary: The provided document is a 510(k) premarket notification for a physical bone screw system. The "study" for acceptance involves a comparison of the new device's characteristics (materials, design, intended use) to those of a legally marketed predicate device to demonstrate substantial equivalence. It does not involve clinical performance studies with patient data, AI algorithms, or expert ground truth adjudication as described in your prompt criteria, which are more relevant to diagnostic or AI-powered devices. The FDA's acceptance of this 510(k) indicates that they agreed the device is substantially equivalent to the predicate, and therefore, does not raise new questions of safety or effectiveness.

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