The Nexus Spine Stable-C Interbody System is an anterior cervical interbody fusion system indicated for use in sketally mature patients with cervical disease (DDD) at one level from C2-T1. DDD is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies. The Stable-C Interbody System is a stand alone system intended to be used with the bone anchors provided. The system is intended to be used with autogenous or allogenic bone graft comprised of cancellous, cortical, and/or corticocancellous bone graft to facilitate fusion. The system is to be used in patients who have had six weeks of non-operative treatment.

Device Description

The Stable-C Interbody System is an anterior cervical interbody device comprised of an interbody cage (lordotic angles of 0, °6°, and 12°) made from titanium alloy (Ti-6Al-4V) per ASTM F3001 and two fixation anchors made from titanium alloy (Ti-6-Al-4V ELI) per ASTM F136. The integrated fixation anchors may not provide adequate stability for all situations. The Surgeon should consider the appropriate fixation required for each patient and determine if additional supplemental fixation may be needed. When used without the supplied fixation, the Stable-C is intended for use with supplemental fixation (e.g., anterior plate, posterior pedicle screws). The device is offered in a variety of sizes to accommodate patient anatomy. The devices and instruments are provided clean and non-sterile for steam sterilization at the user's facility.

The subject system seeks to gain clearance for updated indications for use and design changes to the previously cleared device.

AI/ML Overview

The provided document is a 510(k) premarket notification for a medical device called the "Stable-C Interbody System," which is an anterior cervical interbody fusion system. It is important to note that this document is for a physical medical implant (an intervertebral fusion device), not an artificial intelligence (AI) or software-as-a-medical-device (SaMD) product.

Therefore, the requested information regarding "acceptance criteria" and "the study that proves the device meets the acceptance criteria" in the context of AI/SaMD (e.g., test sets, data provenance, expert ground truth, MRMC studies, standalone performance, training sets) is not applicable to this submission.

The "acceptance criteria" and "study that proves the device meets the acceptance criteria" for a traditional medical device like the Stable-C Interbody System are based on:

Substantial Equivalence: The primary method for clearance is demonstrating substantial equivalence to a legally marketed predicate device. This involves comparing:
- Indications for Use
- Technological Characteristics (e.g., materials, design, operating principles)
- Performance Data (bench testing, and in some cases, animal or clinical data if differences in technological characteristics raise new questions of safety or effectiveness).
Performance Testing: Bench testing (e.g., mechanical, durability, material properties) to ensure the device performs as intended and is safe.
Biocompatibility: Ensuring the materials used are biocompatible.
Sterilization: Validation of sterilization methods.

Based on the provided document, here's what can be extracted regarding the "acceptance criteria" and "study" for this physical device:

1. A table of "acceptance criteria" and "reported device performance":

Since this is a physical implant, the "acceptance criteria" are not quantitative thresholds like sensitivity/specificity for an AI model. Instead, they are met through equivalence and performance testing.

Acceptance Criteria Category	Reported Device Performance / Assessment Method
Substantial Equivalence	Demonstrated equivalence to predicate devices: - Primary Predicate: Nexus Spine, LLC, Stable-C Interbody System (K181621) - Secondary Predicates: Aesculap ArcadiusXP C Spinal System (K153629), Genesys Spine AIS-C Cervical Stand-Alone System (K181295) - Justification: "Insignificant differences" between subject device and primary predicate; Indications for Use expanded similar to Genesys Spine predicate; Materials identical to primary predicate. "Slight geometry differences" were addressed by testing. Conclusion: "does not raise new questions about safety and effectiveness."
Mechanical Performance	Confirmatory bench performance testing performed: - Dynamic axial compression per ASTM F2077-18 - Dynamic axial compression shear per ASTM F2077-18 - Reported Outcome: "Testing has confirmed that the proposed design changes and change in indications do not raise new issues of safety and effectiveness." (Implying the device met relevant performance specifications for these tests, although specific numerical results/acceptance limits are not detailed in this summary for confidentiality reasons).
Biological Performance	Additional cadaveric testing conducted: - Reported Outcome: "Cadaveric validation have shown that the subject Stable-C Interbody devices perform equivalent to the predicate devices." (This is likely to demonstrate the functional biomechanical performance in a more realistic anatomical setting, implicitly meeting "acceptance" by demonstrating equivalence to the established predicate).
Materials	- Interbody cage: titanium alloy (Ti-6Al-4V) per ASTM F3001 - Fixation anchors: titanium alloy (Ti-6-Al-4V ELI) per ASTM F136 - Reported Outcome: "The Materials of the subject device are identical to those of the primary predicate." (This implies biocompatibility and material strength are accepted based on the predicate).
Device Configuration	- Varied sizes available to accommodate patient anatomy. - Provided clean and non-sterile for steam sterilization at user's facility (implies sterilization validation was performed, a standard requirement). - Integrated fixation anchors, but supplemental fixation advisable if anchors don't provide adequate stability (addressing a potential use-case limitation).

2. Sample size used for the test set and the data provenance, etc.:

Sample Size for Test Set: This concept doesn't apply to this type of device in the same way it would for AI where a distinct "test set" of images/data is used. For physical devices, "test samples" refer to the number of physical devices produced and subjected to mechanical/biological testing. The document states "confirmatory bench performance testing was performed on the subject Stable-C interbody devices" but does not specify the number of devices or "samples" tested in the summary. For cadaveric testing, it "was conducted on the subject IBDs," again without specifying the number of cadaveric specimens.
Data Provenance (e.g., country of origin, retrospective/prospective): Not applicable for physical device bench testing. Cadaveric testing would typically be performed in a lab setting.

3. Number of experts used to establish the ground truth... and qualifications:

Not applicable. Ground truth for a physical implant is established by engineering specifications, material standards, and biomechanical principles, not by expert interpretation of images for disease.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

Not applicable. Adjudication methods are for human reader performance assessments in image interpretation, which is not relevant here.

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. MRMC studies are for AI/SaMD products used to assist human interpretation of medical images.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Not applicable. This device is a physical implant; there is no "algorithm" to be evaluated for standalone performance.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

For physical implants, "ground truth" is typically defined by:
- Engineering Specifications: Device dimensions, material properties, tolerance limits.
- Validated Test Methods: Adherence to recognized standards (e.g., ASTM F2077-18 for spinal implants) which define how performance is measured and acceptable ranges.
- Biomechanical Equivalence: Demonstrating that the new device performs similarly to a predicate device in relevant biomechanical tests.

8. The sample size for the training set:

Not applicable. There is no AI model requiring a training set for this physical device.

9. How the ground truth for the training set was established:

Not applicable. Also related to AI model training.

In summary, the provided document is a regulatory submission for a traditional Class II medical device (a spinal implant) and its clearance pathways rely on demonstrating substantial equivalence and meeting specified physical and mechanical performance characteristics, not on methodologies typically associated with the evaluation of AI or SaMD products.

Summary

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August 21, 2023

Nexus Spine, LLC % Christine Scifert Partner MRC Global 9085 E. Mineral Cir., Suite 110 Centennial, Colorado 80112

Re: K231763

Trade/Device Name: Stable-C Interbody System Regulation Number: 21 CFR 888.3080 Regulation Name: Intervertebral Body Fusion Device Regulatory Class: Class II Product Code: OVE Dated: June 15, 2023 Received: June 16, 2023

Dear Christine Scifert:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely.

Brent Showalter -S

Brent Showalter, Ph.D. Assistant Director DHT6B: Division of Spinal Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K231763

Device Name Stable-C Interbody System

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)

☑ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

Stable-C Interbody System August 7, 2023

Company: Nexus Spine, LLC 2825 East Cottonwood Parkway Suite 330 Salt Lake City, UT 84121

Primary Contact: Christine Scifert - Partner MRC Global 9085 E. Mineral Cir., Suite 110 Centennial, CO 80112 Phone: (901) 831-8053 Email: christine.scifert@AskMRCGlobal.com
Company/Secondary Jared Crocker Contact: Vice President of Quality and Regulatory Affairs Nexus Spine, LLC Phone: (801) 702-8592 jared.crocker@nexusspine.com
- Stable-C Interbody System Trade Name: Common Name: Intervertebral Fusion Device With Integrated Fixation, Cervical
  - Classification: Class II
  - Regulation: 21 CFR 888.3080 (Intervertebral Fusion Device With Integrated Fixation, Cervical)
- Panel: Orthopedic Product Code: OVE Primary Predicate: Nexus Spine, LLC Stable-C Interbody System – K181621

Device Description:

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plate, posterior pedicle screws). The device is offered in a variety of sizes to accommodate patient anatomy. The devices and instruments are provided clean and non-sterile for steam sterilization at the user's facility.

The subject system seeks to gain clearance for updated indications for use and design changes to the previously cleared device.

Indications for Use:

The Nexus Spine Stable-C Interbody System is an anterior cervical interbody fusion system indicated for use in skeletally mature patients with cervical disc disease (DDD) at one level from C2-T1. DDD is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies. The Stable-C Interbody System is a stand alone system intended to be used with the bone anchors provided. The system is intended to be used with autogenous or allogenic bone graft comprised of cancellous, cortical, and/or corticocancellous bone graft to facilitate fusion. The system is to be used in patients who have had six weeks of non-operative treatment.

Substantial Equivalence:

The subject Nexus Spine Stable-C Interbody System is substantially equivalent to the following predicate devices:

Primary Predicate:

Nexus Spine, LLC, Stable-C Interbody System K181621 ●

Secondary Predicate:

Aesculap ArcadiusXP C Spinal System - K153629
. Genesys Spine AIS-C Cervical Stand-Alone System - K181295

There are insignificant differences between the subject Stable-C Interbody System and the primary predicate (K181621). The Indications for Use for the subject device have been expanded to specify use of the integrated anchors, similar to the predicate Genesys Spine AIS-C Stand Alone System (K181295). The Materials of the subject device are identical to those of the primary predicate. There are slight geometry differences between the subject and predicate devices but testing and cadaveric validation have shown that the subject Stable-C Interbody devices perform equivalent to the predicate devices. Thus, it can be concluded that the subject does not raise new questions about safety and effectiveness.

Performance Testing:

Confirmatory bench performance testing was performed on the subject Stable -C interbody devices dynamic axial compression and dynamic axial compression shear per ASTM F2077-18. Additional cadaveric testing was conducted on the subject IBDs. Testing has confirmed that the proposed design changes and change in indications do not raise new issues of safety and effectiveness and therefore, the subject device is substantially equivalent to the previously cleared device.

Conclusion:

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Based on the performance analysis and the comparison to the predicate devices, the subject device is determined to be substantially equivalent to the predicate devices.

Regulation Number and Section

§ 888.3080 Intervertebral body fusion device.

(a)
Identification. An intervertebral body fusion device is an implanted single or multiple component spinal device made from a variety of materials, including titanium and polymers. The device is inserted into the intervertebral body space of the cervical or lumbosacral spine, and is intended for intervertebral body fusion.(b)
Classification. (1) Class II (special controls) for intervertebral body fusion devices that contain bone grafting material. The special control is the FDA guidance document entitled “Class II Special Controls Guidance Document: Intervertebral Body Fusion Device.” See § 888.1(e) for the availability of this guidance document.(2) Class III (premarket approval) for intervertebral body fusion devices that include any therapeutic biologic (e.g., bone morphogenic protein). Intervertebral body fusion devices that contain any therapeutic biologic require premarket approval.
(c)
Date premarket approval application (PMA) or notice of product development protocol (PDP) is required. Devices described in paragraph (b)(2) of this section shall have an approved PMA or a declared completed PDP in effect before being placed in commercial distribution.