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.

AI/ML Overview

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.

Acceptance Criteria (Implied by Substantial Equivalence for a Bone Screw System)	Reported Device Performance (Nexa bone screw system vs. Predicate)
Intended Use Equivalence: Same indications for use.	Meets: Nexa and Charlotte Snap-Off Screw have the same indications for use (fixation of fractures, fusions, or osteotomies of bones of the hand and foot).
Technological Characteristics Equivalence: - Same principle of operation. - Similar design (shape, size). - Same materials. - Single-use. - Surgical implantation duration (>30 days).	Meets: - Both are screw fixation devices. - Similar in shape and size. - Both use Titanium (6AL-4V ELI / 6AL-4V alloy). - Both are single-use. - Both are intended for surgical implantation longer than 30 days.
Safety and Effectiveness: No new questions of safety or effectiveness are raised.	Meets: The submission asserts "no new materials are introduced" and "the new device is substantially equivalent to the predicate device," implying no new safety/effectiveness concerns.

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.

Summary

{0}------------------------------------------------

K053394 r½

510 (k) Summary

DEC 1 4 2005

Summary of 510 (k) safety and effectiveness information upon which the substantial equivalence determination is based:

Prepared:	December 6, 2005
Applicant:	Nexa Orthopedics, Inc., (dba FuturaBiomedical, LLC)10675 Sorrento Valley Road, Suite 100San Diego, CA 92121
Telephone:	858-866-0660
Fax:	858-866-0661
Contact:	Louise M. Focht
Device Name:	Nexa bone screw system
Device Trade Name:	Nexa bone screw system
Device Classification:	Class II
Reviewing Panel:	Orthopedic
Regulation Number	888.3040
Product Code:	87 HWC
Predicate Device:	K043583 - Charlotte Snap-off ScrewSystem
Registration Number:	2030833
Owner Operator Number:	9028319

Device Description:

Indications for Use:

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

Comparison to Predicate Device:

{1}------------------------------------------------

KC53374 P²/₂

The legally marketed predicate device to which this device is substantially equivalent is the Wright Medical Charlotte Snap-Off Screw

Regulatory Class: II 87 HWC Product Code:

Table 1. Comparison of Nexa Orthopedics and Wright Medical Snap off screw.

Item	Nexa Orthopedics	Wright Medical
Product Name	Nexa bone screw system	Charlotte Snap-Off Screw
Use	Single use	Single use
Fixation	Screw	Screw
Material	Titanium 6AL-4V ELI	Titanium alloy 6AL-4V
Sizes	6 sizes	3 sizes
Indications for use	The Nexa bone screw system provides fixation for fractures, fusions, or osteotomies of bones of the hand and foot.	The Charlotte Snap Off Screw is indicated for fixation of bone fractures or for bone reconstruction. Examples include:Fixation of Small Bone FragmentsWeil osteotomyMono-cortical fixationOsteotomies and fractures fixation in the foot and hand.

Similarities of the Nexa Orthopedics bone screw system and Wright Medical Snap-Off Screw include:

Both devices are: intended for single use only; intended for surgical implantation longer than 30 days; both devices are screws for fixation of fractures, fusions, or osteotomies, of bones of the hand and foot; both devices are made of industry standard materials, no new materials are introduced in either product; Both devices are comparably sized; both devices have the same indications for use.

Summary:

The device and the predicate device have similar design characteristics and intended use. The new device is substantially equivalent to the predicate device.

{2}------------------------------------------------

Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo features a stylized caduceus, which is a symbol often associated with medicine and healthcare. The caduceus is depicted with three lines forming the wings and a snake-like form at the bottom. The text "DEPARTMENT OF HEALTH AND HUMAN SERVICES . USA" is arranged in a circular pattern around the caduceus.

Public Health Service

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC 1 4 2005

Mr. Louise M. Focht Nexa Orthopedics, Inc., 10675 Sorrento Valley Road, Suite 100 San Diego, California 92121

Re: K053394

Trade/Device Name: Nexa bone screw system Regulation Number: 21 CFR 888.3040 Regulation Name: Smooth or threaded metallic bone fixation fastener. Regulatory Class: II Product Code: HWC Dated: December 5, 2005 Received: December 6, 2005

Dear Mr. Focht:

We have reviewed your Section 510(k) premarket notification of intent to market the indication We have reviewed your Section 9 ro(x) premained in substantially equivalent (for the indications referenced above and have determined the arrest of the devices marketed in interstate for use stated in the encrosule) to regary maneroup of the Medical Device Amendments, or to commerce prior to May 28, 1970, the charger and the Federal Food, Drug, 1994, Drug, devices that have been reclassified in accerance wear a premarket approval application (PMA).)
and Cosmetic Act (Act) that do not require approval of a premisions of the Act, and Cosment Act (Act) that do not require the general controls provisions of the Act. The You may, merelore, market the devices, belject of the ments for annual registration, listing of general controls provisions of the necessor and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it If your device is classified (seculove) me. Existing major regulations affecting your device can
may be subject to such additional controls. Existing major may be subject to such additional controller Entrologically - - 000 to 898. In addition, FDA may be found in the Ood neements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean Please be advised that I Dri 3 issualite of wouldevice complies with other requirements of the Act
that FDA has made a determination that your device complies with other requ that IDA has made a decerminations administered by other Federal agencies. You must or any rederal statutes and regulations admiding, but not limited to: registration and listing (21 Comply with an the Free STOQuentiality, 2001 manufacturing practice requirements as set CFR in the quality systems (DS) regulation (21 CFR Part 820); and if applicable, the electronic form in the quality systems (Sections 531-542 of the Act); 21 CFR 1000-1050. product radiation control pro herems (2001) (2006) 100 marketing your device as described in your Section 510(k) This letter with anow you to begin manieting of substantial equivalence of your device to a legally

{3}------------------------------------------------

Page 2 - Mr. Louise M. Focht

marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please If you desire spoonly and (240) 276-0120. Also, please note the regulation entitled, Connect the Office of Course to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small other general international and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

r Mark N. Melkerson Acting Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

{4}------------------------------------------------

Indications for Use

510 (k) Number (If Known): K053394
Device Name: Nexa bone plate and screw system

Indications for Use:

・

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

Prescription Use X
(Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Countor Usc (21 CFR 801 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE OF NEEDED)

(Division Sign-Off)

Division of General, Reand Neurological Device

510(k) Number K053394

Regulation Number and Section

§ 888.3040 Smooth or threaded metallic bone fixation fastener.

(a)
Identification. A smooth or threaded metallic bone fixation fastener is a device intended to be implanted that consists of a stiff wire segment or rod made of alloys, such as cobalt-chromium-molybdenum and stainless steel, and that may be smooth on the outside, fully or partially threaded, straight or U-shaped; and may be either blunt pointed, sharp pointed, or have a formed, slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a guide pin for insertion of other implants, or it may be implanted through the skin so that a pulling force (traction) may be applied to the skeletal system.(b)
Classification. Class II.