The Tera Lumbar Interbody Fusion System is indicated for intervertebral body fusion of the spine in skeletally mature patients who have had at least six months of non-operative treatment. The device systems are designed for use with allogenic bone graft comprised of cancellous and/or corticocancellous bone graft and/or autograft to facilitate fusion.

The Tera Lumbar Interbody Fusion System is intended for use at either one level or two contiguous levels in the lumbar spine, from L2 to S1, for the treatment of degenerative disc disease (DDD) with up to Grade I spondylolisthesis. DDD is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies.

The Tera Lumbar Interbody Fusion System is intended to be used with supplemental spinal fixation system cleared for use in the lumbosacral spine.

Device Description

The Tera Lumbar Interbody Fusion System consists of intervertebral body fusion devices intended for lumbar interbody fusion using a transforaminal lumbar interbody fusion surgical approach (TLIF), an oblique transforaminal interbody fusion surgical approach (Oblique TLIF), or a posterior lumbar interbody fusion surgical approach (PLIF). The devices are intended to improve stability of the spine while supporting fusion. The Tera Lumbar Interbody Fusion System cages are intended for use at one or two contiguous levels in the lumbar spine (L2-S1). The components are offered in different shapes and sizes to meet the requirements of the individual patient's anatomy and are provided sterile.

Tera Lumbar Interbody Fusion System cages are made of titanium alloy (Ti-6Al-4V ELI) per ASTM F3001 Standard Specification for Additive Manufacturing Titanium-6 Aluminum-4 Vanadium ELI (Extra Low Interstitial) with Powder Bed Fusion. All cages are manufactured using the L-PBF (laser powder bed fusion) additive manufacturing method. L-PBF allows for the formation of solid, non-porous cages with a layered porous lattice structure on the surfaces of the components, including the surfaces of the interior graft window. This intricate structure facilitates bone in-growth by providing a larger surface of implant/bone contact than a buffed surface. The cages are also titanium anodized to allow for identification of various heights by color.

Tera-T Ti Interbody cages, Tera-O Ti Interbody cages, and Tera-P Ti Interbody cages are also available with a Promimic HAnano Surface (hydroxyapatite (HA) coating). Cages are coated with a 20nm HA layer composed of crystalline hydroxyapatite particles that mimic human bone tissue through shape, composition, and structure. This surface treatment increases implant anchoring by facilitating osseointegration and enhancing early bone growth. All Tera Lumbar Interbody Fusion System implants are only available sterile packaged.

Non-sterile, reusable surgical instruments to support implantation of the system are provided for use with Tera Lumbar Interbody Fusion System devices are provided in steam sterilization trays.

AI/ML Overview

The provided text describes a 510(k) clearance for a medical device called the "Tera Lumbar Interbody Fusion System." This document is a regulatory approval for a physical medical device (an implant used in spinal fusion surgery), not a software or AI-driven diagnostic device.

Therefore, the requested information about acceptance criteria for AI/software performance, such as MRMC studies, ground truth establishment, training set details, or expert adjudication, is not applicable to this document. The clearance is based on mechanical performance testing and substantial equivalence to a predicate device.

Here's a breakdown of the relevant information provided in the document regarding the device's acceptance and testing:

Acceptance Criteria and Device Performance for Tera Lumbar Interbody Fusion System

The Tera Lumbar Interbody Fusion System is a physical medical device. Its acceptance criteria and performance are based on mechanical testing to demonstrate substantial equivalence to previously cleared predicate devices, rather than AI or software performance metrics.

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly present a table of acceptance criteria with specific numerical targets and reported values. Instead, it states that the device was tested against recognized ASTM standards, and its performance met the acceptance criteria of these standards.

Acceptance Criteria Category	Standard / Reference	Reported Device Performance
Mechanical Strength	ASTM F2077	Demonstrated substantial equivalence to predicate devices under various loading conditions. Performance met required criteria for intended use.
- Static Axial Compression	ASTM F2077	Passed / Met Criteria
- Static Axial Compression Shear	ASTM F2077	Passed / Met Criteria
- Dynamic Axial Compression	ASTM F2077	Passed / Met Criteria
- Dynamic Axial Compression Shear	ASTM F2077	Passed / Met Criteria
Subsidence	ASTM F2267	Passed / Met Criteria
Material Properties	ASTM F3001	Passed / Met Criteria (Tensile, Microstructure, Chemical Composition)
Biocompatibility	N/A (Standard implied)	Testing conducted, results satisfactory
Sterilization & Packaging	N/A (Standard implied)	Validation conducted, results satisfactory

Note: The document states, "Performance equivalence demonstrated that the subject device met the acceptance criteria of the standards and is substantially equivalent to the predicate devices." This indicates that the established acceptance criteria were the thresholds defined by the respective ASTM standards for intervertebral body fusion devices.

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

The document refers to "mechanical performance testing" and "worst-case analysis and resulting worst-case configuration mechanical testing." It doesn't specify a precise numerical sample size for the physical devices tested (e.g., "N units were tested"). However, typically, mechanical performance testing of medical implants involves a statistically sufficient number of samples to ensure robust results, often following specific sample size recommendations within the testing standards.

Test Set Sample Size: Not explicitly stated as a number of devices (e.g., "10 units"). However, "worst-case configuration mechanical testing" implies selected configurations representative of the most challenging conditions.
Data Provenance: The data is generated from in-vitro (laboratory) mechanical testing of the manufactured device. It is not patient or clinical data. No country of origin for data or retrospective/prospective status is applicable as it's not a clinical study.

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

This question is not applicable for this type of device clearance. Ground truth, in the context of AI/software, refers to human expert annotations or pathological diagnoses. For mechanical devices, "ground truth" is defined by the performance requirements of the relevant engineering standards (e.g., ASTM F2077, ASTM F2267, ASTM F3001). The "experts" in this context would be the engineers and technicians performing the tests and validating the results against the standard requirements.

4. Adjudication Method for the Test Set

This question is not applicable. Adjudication methods (e.g., 2+1, 3+1) are used for resolving discrepancies in human expert annotations for AI ground truth. For mechanical testing, the results are quantitative measurements against predefined thresholds in the standards.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, a MRMC study was NOT done. MRMC studies are specific to evaluating the impact of AI on human reader performance, typically in diagnostic imaging. This device is a physical implant, not a diagnostic AI tool.

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

This question is not applicable. This device is not an algorithm. The "standalone" performance here refers to the device's mechanical integrity on its own without human interaction during the test (other than setting up the test). The mechanical tests performed (static/dynamic compression, shear, subsidence) are essentially "standalone" evaluations of the device's physical properties.

7. The Type of Ground Truth Used

The "ground truth" for this device's performance validation is defined by the acceptance criteria specified in the relevant ASTM (American Society for Testing and Materials) standards for intervertebral body fusion devices and titanium alloys. These standards define the mechanical properties and performance thresholds that the device must meet.

8. The Sample Size for the Training Set

This question is not applicable. This device is a physical implant, not an AI model, so there is no "training set."

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

This question is not applicable as there is no training set for a physical medical device.

Summary

FDA 510(k) Clearance Letter - Tera Lumbar Interbody Fusion System

Page 1

U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

Doc ID # 04017.07.05

June 2, 2025

Acuity Surgical Devices, LLC
Chuck Forton
VP of New Product Development
8710 N. Royal Lane
Irving, Texas 75063

Re: K251335
Trade/Device Name: Tera Lumbar Interbody Fusion System (Various PNs)
Regulation Number: 21 CFR 888.3080
Regulation Name: Intervertebral Body Fusion Device
Regulatory Class: Class II
Product Code: MAX
Dated: April 29, 2025
Received: April 30, 2025

Dear Chuck Forton:

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 (the 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 available 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.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"

Page 2

June 2, 2025

Acuity Surgical Devices, LLC
Chuck Forton
VP of New Product Development
8710 N. Royal Lane
Irving, Texas 75063

Dear Chuck Forton:

K251335 - Chuck Forton Page 2

(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 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-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/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-devices/device-advice-comprehensive-regulatory-assistance/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).

Page 3

K251335 - Chuck Forton Page 3

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

Page 4

FORM FDA 3881 (6/20) Page 1 of 1

DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2023
See PRA Statement below.

510(k) Number (if known)
K251335

Device Name
Tera Lumbar Interbody Fusion System (Various PNs)

Indications for Use (Describe)

The Tera Lumbar Interbody Fusion System is intended to be used with supplemental spinal fixation system cleared for use in the lumbosacral spine.

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

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DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

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Page 5

510(k) Summary

K251335

Contact Details

Applicant Name: Acuity Surgical Devices LLC
Applicant Address: 8710 N. Royal Lane
Irving TX, 75063 United States
Applicant Contact No.: (512) 585-3537
Applicant Contact: Mr. Chuck Forton
Applicant Contact email: cforton@acuitysurgical.com

Date Prepared: May 16, 2025

Device Name

Device Trade Name: Tera Lumbar Interbody Fusion System (Various PNs)
Common Name: Intervertebral body fusion device
Classification Name: Intervertebral Fusion Device With Bone Graft, Lumbar
Regulation Number: 888.3080
Product Code(s): MAX

Legally Marketed Predicate Devices

510(k) Number	Product Code	Trade Name	Manufacturer
Primary Predicate Device
K221535	MAX	Align Lumbar Interbody Fusion Device	Acuity Surgical Devices LLC
Additional Predicate Devices
K243386	OVD	Ventris	Acuity Surgical Devices LLC
K222561	OVD	Align HA	Acuity Surgical Devices LLC

Device Description

Page 6

Non-sterile, reusable surgical instruments to support implantation of the system are provided for use with Tera Lumbar Interbody Fusion System devices are provided in steam sterilization trays.

Intended Use / Indications for Use

The Tera Lumbar Interbody Fusion System is intended to be used with supplemental spinal fixation system cleared for use in the lumbosacral spine.

Page 7

Indications for Use Comparison

The Tera Lumbar Interbody Fusion System has identical Indications for Use as the primary predicate device, Align Lumbar Interbody Fusion System (K221535) and similar Indications for Use to the additional predicate devices cleared in K243386 and K222561. The subject device is indicated for the same patient population, condition, and mechanism of action as the primary predicate device.

Technological Comparison

The Tera Lumbar Interbody Fusion System has the same indications, design, similar dimensions, and uses identical materials as the primary predicate device, K221535. The subject device also has identical or similar technological characteristics as the primary predicate device.

Differences between the subject device and primary predicate device include a change in the device name, updated implant cage inserter interface designs, additional implant heights and lordosis offerings, an update to instrument designs, additional instrument options, and an additional HA coating option. The additive manufacturing process was also changed to a new supplier, which is identical to the additional predicate device K243386.

The subject device has identical or similar characteristics to additional predicate devices K243386 and K222561 with similar size range and lordosis angle to K243386. The subject device comes with an optional HA coating, which is the same material as the additional predicate device cleared in K222561.

To ensure these technological characteristics do not affect the safety and effectiveness of the subject device, a worst-case analysis and resulting worst-case configuration mechanical testing was conducted on the new implant sizes and configurations. Based on the testing conducted including mechanical performance testing, design validation analysis, biocompatibility testing, and sterilization and packaging validation, it can be concluded that the subject device does not raise any new issues of safety and effectiveness as compared to the primary predicate K221535, and additional predicate devices K243386 and K222561.

The Tera Lumbar Interbody Fusion System is substantially equivalent to the legally marketed predicate device Align Lumbar Interbody Fusion System (K221535) under regulation 21 CFR 888.3080, product code MAX.

Page 8

Non-Clinical and/or Clinical Tests Summary & Conclusions

The subject device underwent mechanical performance testing to validate that the performance of the worst-case subject device is substantially equivalent to the previously cleared predicate devices. Test methods including static axial compression, static axial compression shear, dynamic axial compression, and dynamic axial compression shear per ASTM F2077 Test Methods for Intervertebral Body Fusion Devices, and subsidence testing per ASTM F2267 Standard Test Method for Measuring Load Induced Subsidence of Intervertebral Body Fusion Devices Under Static Axial Compression ensured that the design features of the subject device met the required mechanical strength criteria for their intended use. Additional testing included tensile testing, microstructure assessment, and chemical composition assessment per ASTM F3001. The performance testing demonstrated substantial equivalence between the subject and predicate devices. The results of the non-clinical testing did not identify any new or increased risks associated with the change in additive manufacturing supplier. Performance equivalence demonstrated that the subject device met the acceptance criteria of the standards and is substantially equivalent to the predicate devices.

Clinical Testing was Not Applicable.

The performance testing demonstrated substantial equivalence between the subject and predicate devices. The results of the non-clinical testing did not identify any new or increased risks associated with the change in additive manufacturing supplier. Performance equivalence demonstrated that the subject device met the acceptance criteria of the standards and is 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.