The Wenzel Spine VariLift-C Interbody Fusion System is indicated for use in skeletally mature patients with cervical disc degeneration (DDD) and/or cervical spinal instability, as confirmed by imaging studies (radiographs, CT, MRI) that results in radiculopathy, myelopathy, and/or pain at one or multiple contiguous levels from C2/C3 to C7/T1. These DDD patients may have up to Grade 1 spondylolisthesis or retrolisthesis at the involved level(s). The Wenzel Spine VariLift-C Interbody Fusion System is used to facilitate intervertebral body fusion in the cervical spine and is placed in a unilateral or a bilateral fashion via an anterior approach using autogenous and/or allogeneic bone graft comprised of cancellous, and/or corticocancellous bone graft, or a bone void filler as cleared by FDA for use in intervertebral body fusion to facilitate fusion. When used at one disc level, the Wenzel Spine VariLift-C interbody Fusion System may be used with or without supplemental fixation. When used at multiple contiguous levels, the Wenzel Spine VariLift-C Interbody Fusion System is intended to be used with supplemental fixation. Patients should have at least six (0) weeks of non-operative treatment prior to treatment with an intervertebral fusion device.
Device Story
VariLift-C is a self-tapping, expandable, cylindrical-ovoid interbody fusion device; features interior sliding wedge; includes fenestrations for bony ingrowth. Implanted via anterior approach in unilateral or bilateral fashion; used with autogenous/allogeneic bone graft or cleared bone void filler. Facilitates intervertebral body fusion in cervical spine. Used in clinical settings by surgeons. Provides structural support to vertebral endplates; promotes fusion; potentially alleviates radiculopathy, myelopathy, or pain associated with DDD or spinal instability. Used with or without supplemental fixation depending on number of levels treated.
Clinical Evidence
No clinical data provided. Substantial equivalence is supported by bench testing and comparison of technological characteristics to predicate devices.
Technological Characteristics
Cylindrical-ovoid, self-tapping, expandable interbody fusion device. Material: Medical grade titanium alloy (Ti6Al4V) per ASTM F136. Features interior sliding wedge and fenestrations for bony ingrowth. Mechanical device; no software or energy source.
Indications for Use
Indicated for skeletally mature patients with cervical disc degeneration (DDD) and/or cervical spinal instability (C2/C3 to C7/T1) presenting with radiculopathy, myelopathy, or pain. Includes patients with up to Grade 1 spondylolisthesis or retrolisthesis. Requires 6 weeks of failed non-operative treatment.
Regulatory Classification
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.
Special Controls
*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.
VariLift-LX Interbody Fusion System, VariLift-C Interbody Fusion System (K180822)
Submission Summary (Full Text)
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September 27, 2023
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Wenzel Spine, Inc. % Justin Eggleton Vice President, Head of Musculoskeletal Regulatory Affairs MCRA 803 7th Street. NW Washington, District of Columbia 20001
# Re: K231076
Trade/Device Name: VariLift®-C Interbody Fusion System Regulation Number: 21 CFR 888.3080 Regulation Name: Intervertebral Body Fusion Device Regulatory Class: Class II Product Code: ODP Dated: August 9, 2023 Received: August 9, 2023
# Dear Justin Eggleton:
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" (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).
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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 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-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 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.
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-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,
# Katherine D. Kavlock -S
for
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) K231076
Device Name VariLift®-C Interbody Fusion System
#### Indications for Use (Describe)
The Wenzel Spine VariLift-C Interbody Fusion System is indicated for use in skeletally mature patients with cervical disc degeneration (DDD) and/or cervical spinal instability, as confirmed by imaging studies (radiographs, CT, MRI) that results in radiculopathy, myelopathy, and/or pain at one or multiple contiguous levels from C2/C3 to C7/T1. These DDD patients may have up to Grade 1 spondylolisthesis or retrolisthesis at the involved level(s).
The Wenzel Spine VariLift-C Interbody Fusion System is used to facilitate intervertebral body fusion in the cervical spine and is placed in a unilateral or a bilateral fashion via an anterior approach using autogenous and/or allogeneic bone graft comprised of cancellous, and/or corticocancellous bone graft, or a bone void filler as cleared by FDA for use in intervertebral body fusion to facilitate fusion. When used at one disc level, the Wenzel Spine VariLift-C interbody Fusion System may be used with or without supplemental fixation. When used at multiple contiguous levels, the Wenzel Spine VariLift-C Interbody Fusion System is intended to be used with supplemental fixation. Patients should have at least six (0) weeks of non-operative treatment prior to treatment with an intervertebral fusion device.
Type of Use (Select one or both, as applicable)
| <span style="font-size: large;">☑</span> Prescription Use (Part 21 CFR 801 Subpart D) | <span style="font-size: large;">☐</span> Over-The-Counter Use (21 CFR 801 Subpart C) |
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# 510(k) Summary
| Device Trade Name: | VariLift®-C Interbody Fusion System |
|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------|
| Manufacturer: | Wenzel Spine, Inc.<br>1130 Rutherford Ln #200<br>Austin, TX 78753 |
| Prepared by: | Justin Eggleton<br>MCRA, LLC<br>803 7th Street, NW, 3rd Floor<br>Washington, DC 20001<br>Office: 202.552.5800<br>jeggleton@mcra.com |
| Date Prepared: | September 25, 2023 |
| Classifications: | 21 CFR §888.3080 |
| Classification Name: | Intervertebral body fusion device |
| Common Name: | Intervertebral Fusion Device With Bone Graft, Cervical |
| Class: | II |
| Product Codes: | ODP |
| Primary Predicate: | K222276, CONDUIT™ Cervical Cage |
| Additional Predicate: | K180822, VariLift® -C Interbody Fusion System |
# Indications For Use:
The Wenzel Spine VariLift Cervical Interbody Fusion System is indicated for use in skeletally mature patients with cervical disc degeneration (DDD) and/or cervical spinal instability, as confirmed by imaging studies (radiographs, CT, MRI) that results in radiculopathy, myelopathy, and/or pain at one or multiple contiguous levels from C2/C3 to C7/T1. These DDD patients may have up to Grade 1 spondylolisthesis or retrolisthesis at the involved level(s).
The Wenzel Spine VariLift Cervical Interbody Fusion System is used to facilitate intervertebral body fusion in the cervical spine and is placed in a unilateral fashion via an anterior approach using autogenous and/or allogeneic bone graft comprised of cancellous, and/or corticocancellous bone graft, or a bone void filler as cleared by FDA for use in intervertebral body fusion to facilitate fusion. When used at one disc level, the Wenzel Spine VariLift-C interbody Fusion System may be used with or without supplemental fixation. When used at multiple
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contiguous levels, the Wenzel Spine VariLift-C Interbody Fusion System is intended to be used with supplemental fixation. Patients should have at least six (6) weeks of non-operative treatment prior to treatment with an intervertebral fusion device.
# Device Description:
The VariLift® Cervical Interbody Fusion device (VariLift-C) is a self-tapping, expandable device with an interior sliding wedge. VariLift-C is cylindrical-ovoid in shape, which is adapted to the general shape of the vertebral endplates. The grooved and fluted fusion device has fenestrations (graft windows) positioned between each of its four quadrants to allow bony ingrowth and contact with the endplates. The device is manufactured from medical grade titanium alloy (Ti6Al4V) per ASTM F136.
## Predicate Device:
Wenzel Spine, Inc. submits the following information in this Premarket Notification to demonstrate that, for the purposes of FDA's regulation of medical devices, VariLift-C Interbody Fusion System is substantially equivalent in indications, design principles, and performance to the following predicate devices:
#### Primary Predicate
| Manufacturer | Device Name | 510(k) number |
|--------------|------------------------|---------------|
| DePuy Spine | CONDUIT™ Cervical Cage | K222276 |
#### Additional Predicate:
| Manufacturer | Device Name | 510(k) number |
|--------------------|-------------------------------------------------------------------------|---------------|
| Wenzel Spine, Inc. | VariLift-LX Interbody Fusion System, VariLift-C Interbody Fusion System | K180822 |
## Performance Testing Summary:
The substantial equivalence of the VariLift-C interbody Fusion Device to the predicate devices is evidenced by having the same intended use, Indications for Use, material, principles of operation, and fundamental technology.
## Conclusion:
The subject device and the predicate devices have intended use, have similar technological characteristics, and are made of similar materials. The subject and predicate devices are packaged in similar materials and are sterilized using similar methods. VariLift-C Interbody Fusion System is as safe, and as effective, compared to the predicate devices.
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.