The CLS, Wagner Revision and AlloClassic Zweymuller femoral stems will be used in conjunction with the Zirconia Ceramic Total Head. This stem/head combination is intended for prosthetic replacement of the proximal portion of the femur during total hip arthroplasty in which the ball head articulates with a polyethylene acetabular component. Specific diagnostic indications include: - Patient conditions of inflammatory degenerative joint disease (e.g., rheumatoid arthritis) and noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis); - Those patients with failed previous surgery where pain, deformity, or dysfunction persist; and, - Revision of previously failed hip arthroplasty. The CLS Stem, Wagner Revision Stem and AlloClassic Zweymuller Stem are intended for use with or without bone cement.
Device Story
Zirconia Ceramic Total Head designed for articulation with polyethylene acetabular components in total hip arthroplasty. Device consists of spherical zirconia ceramic head with 12/14 taper, compatible with specific Ti-6Al-7Nb alloy femoral stems (CLS, Wagner Revision, AlloClassic Zweymuller). Used by orthopedic surgeons in clinical settings for proximal femoral replacement. Head provides bearing surface for hip joint; intended to address joint disease or revision needs. Static compression testing confirms burst strength meets requirements.
Clinical Evidence
Bench testing only. Static compression testing performed to evaluate burst strength of zirconia ceramic heads.
Technological Characteristics
Zirconia ceramic spherical head; 12/14 taper; 28mm and 32mm diameters; short, medium, and long neck lengths. Compatible with Ti-6Al-7Nb alloy femoral stems featuring Sulzer 12/14 (5°38' cone angle) Morse taper trunnions. Non-software device.
Indications for Use
Indicated for patients requiring total hip arthroplasty due to inflammatory degenerative joint disease (e.g., rheumatoid arthritis), noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis), failed previous surgery with persistent pain/deformity/dysfunction, or revision of failed hip arthroplasty.
Regulatory Classification
Identification
A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.
Predicate Devices
APR Hip System (Sulzer Orthopedics Inc.)
Natural Hip System (Sulzer Orthopedics Inc.)
Submission Summary (Full Text)
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## 510(k) SUMMARY
K973837
In accordance with the Food and Drug Administration Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21 CFR 807, this is to serve as a Summary of Safety and Effectiveness for the use of zirconia ceramic heads with the femoral stems listed below.
| Submitter: | Sulzer Orthopedics Inc.<br>9900 Spectrum Drive<br>Austin, Texas 78717<br>(512) 432-9900 |
|-------------------------|--------------------------------------------------------------------------------------------------------------------------------|
| Date: | September 30, 1997 |
| Contact Person: | Jacquelyn Hughes<br>Manager, Regulatory Affairs |
| Classification Name: | Hip joint metal/ceramic/polymer semi-constrained cemented or<br>nonporous uncemented prosthesis, 21 CFR 888.3353 |
| Common/Usual Name: | Total Hip Prosthesis, Semi-constrained |
| Trade/Proprietary Name: | Zirconia Ceramic Total Head (12/14) for use with the CLS<br>Stem, Wagner Revision Stem, and, AlloClassic Zweymuller<br>Stem SL |
#### SPECIFIC DIAGNOSTIC INDICATIONS
The CLS, Wagner Revision and AlloClassic Zweymuller femoral stems will be used in conjunction with the Zirconia Ceramic Total Head. This stem/head combination is intended for prosthetic replacement of the proximal portion of the femur during total hip arthroplasty in which the ball head articulates with a polyethylene acetabular component. Specific diagnostic indications include:
- Patient conditions of inflammatory degenerative joint disease (e.g., rheumatoid . arthritis) and noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis):
- . Those patients with failed previous surgery where pain, deformity, or dysfunction persist; and,
- Revision of previously failed hip arthroplasty. ●
The CLS Stem. Wagner Revision Stem and AlloClassic Zwevmuller Stem, are intended for use with or without bone cement.
### PRODUCT DESCRIPTION
The CLS Stem. Wagner Revision Stem and AlloClassic Zwevmuller Stem are all designed for use with ceramic heads. These stems are manufactured from Ti-6A1-7Nb alloy and have the same proximal taper which is machined per the specifications of the 12/14 Sulzer taper.
The Zirconia Ceramic Total Head is a spherical head with a 12/14 taper, making it compatible with the above stems. The heads are available in 28mm and 32mm diameters and three neck lengths; short, medium and long.
Static compression testing demonstrated that the burst strength of the zirconia heads exceeds FDA requirements.
### SUBSTANTIAL EQUIVALENCE
The CLS Stem, the Wagner Revision Stem, and the AlloClassic Zweymuller Stem when used with the Zirconia Ceramic Total Head are substantially equivalent to the APR and Natural Hip Systems (Sulzer Orthopedics Inc.).
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Image /page/1/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized image of three human profiles facing to the right, with flowing lines beneath them.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
Ms. Shavawn Evans Parduhn ·Regulatory Affairs Specialist Sulzer Orthopedics Inc. 9900 Spectrum Drive Ausitn, Texas 78717
K973837 Re : CLS Stem, Wagner Revision Stem, AlloClassic Zweymuller Stem, SL for use with Zirconia Ceramic Heads Regulatory Class: II Product Code: LZO October 7, 1997 Dated: Received: October 8, 1997
Dear Ms. Parduhn
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). You may, therefore, market the device, subject to the general controls provisions of the Act and the following limitation that the package insert must reflect that the Metoxit Zirconia Ceramic Femoral Heads are to be used only with Ti-6Al-7Nb hip stems with the Sulzer 12/14 (5°38' cone angle) Morse taper trunnions.
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.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical General regulation (21 CFR Part 820) and that, Devices: through periodic (QS) inspections, the Food and Drug
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Page 2 - Ms. Shavawn Evans Parduhn
Failure to Administration (FDA) will verify such assumptions. comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal Laws or Requlations.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification immediately. An FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address "http://www.fda.gov/cdrh/dsmamain.html".
Sincerely yours,
Celia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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Page 1 of 1
510(k) Number (if known):
Device Name: CLS Stem, Wagner Revision Stem and AlloClassic Zweymuller Stem for Use With Zirconia Ceramic Total Heads
# Indications For Use:
The CLS, Wagner Revision and AlloClassic Zweymuller femoral stems will be used in conjunction with the Zirconia Ceramic Total Head. This stem/head combination is intended for prosthetic replacement of the proximal portion of the femur during total hip arthroplasty in which the ball head articulates with a polyethylene acetabular component. Specific diagnostic indications include:
- Patient conditions of inflammatory degenerative joint disease (e.g., rheumatoid arthritis) and . noninflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis);
- Those patients with failed previous surgery where pain, deformity, or dysfunction persist; and, .
- Revision of previously failed hip arthroplasty. .
The CLS Stem, Wagner Revision Stem and AlloClassic Zweymuller Stem are intended for use with or without bone cement.
#### (PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use X
OR
Over-The-Counter Use
(Optional Format 1-2-96)
correpa
Division Sign-Om
ision
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Division of General Restorative Devices
510(k) Number
510(k) Number K973837
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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.
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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.
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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.