The Triathlon® X3™ UHMWPE Posterior Stabilized and Cruciate Retaining tibial inserts and the Triathlon® X3™ UHMWPE Patellar components are intended to be used with the cemented Triathlon® PS and CR femoral components and cemented Triathlon® Primary Cemented Tibial Tray in primary or revision total knee arthroplasty. The Triathlon® X3™ UHMWPE Patellar components are intended to be used with the femoral components of the previously released Duracon® Total Knee System The Triathlon® PS Total Knee System is intended to be used in situations where the posterior cruciate ligament is absent, or cannot be preserved. The Triathlon CR Total Knee System is intended to accommodate the posterior cruciate ligament (PCL) if it is present. The all polyethylene Triathlon® X3™ UHMWPE Patellar components are intended for implantation with bone cement only.
Device Story
Triathlon® X3™ UHMWPE components are orthopedic implants for total knee arthroplasty; designed as tibial inserts (Cruciate Retaining or Posterior Stabilized) and patellar components (Asymmetric or Symmetric). Implants replace bearing/articulating surfaces of proximal tibia and patella. Used in primary or revision surgery; implanted by orthopedic surgeons in hospital settings. Components function as part of a semi-constrained cemented prosthesis system to restore joint stability and function. Benefits include pain relief and improved mobility for patients with degenerative joint disease or trauma. Device performance validated through bench testing, including wear, fatigue, and shear testing.
Clinical Evidence
No clinical data. Substantial equivalence supported by bench testing including material properties testing, wear testing, disassembly force evaluation, multi-axis fatigue testing, patella shear testing, and finite element modeling of contact stresses.
Technological Characteristics
Components manufactured from X3™ UHMWPE (Ultra-High Molecular Weight Polyethylene). Designs include Cruciate Retaining and Posterior Stabilized tibial inserts, and Asymmetric and Symmetric patellar components. Intended for use with cemented femoral components and tibial trays. Semi-constrained design. Sterilization method not specified.
Indications for Use
Indicated for patients with painful, disabling knee joint disease (osteoarthritis, traumatic arthritis, avascular necrosis, rheumatoid arthritis); post-traumatic loss of joint function; moderate varus, valgus, or flexion deformity; revision of failed knee replacement; or distal femur/proximal tibia fractures. Posterior Stabilized components indicated for ligamentous instability or absent/non-functioning posterior cruciate ligament. Contraindicated in patients with active/latent infection, mental/neuromuscular disorders, compromised bone stock, skeletal immaturity, severe collateral ligament instability, or obesity.
Regulatory Classification
Identification
A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).
Predicate Devices
Triathlon® Tibial Inserts and Patellar
Reference Devices
Duracon® Total Knee System
Submission Summary (Full Text)
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K051146 (pg. 1 of 2)
Triathlon® X3™ UHMWPE Tibial and Patellar Components
510(k) Premarket Notification
# JUL 1 3 2005
### 510(k) Summary of Safety and Effectiveness
| Device: | Triathlon® X3™ UHMWPE Tibial Inserts and Patellar Components |
|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Classification: | 21 CFR 888.3560 - Knee joint, patellofemorotibial,<br>polymer/metal/polymer semi-constrained cemented prosthesis |
| Product Code | 87 JWH, |
| Predicate Devices: | Triathlon® Tibial Inserts and Patellar |
| Contact Person: | Karen Ariemma<br>Senior Regulatory Affairs Specialist<br>Howmedica Osteonics Corp.<br>325 Corporate Drive<br>Mahwah, NJ 07430<br>(201) 831-5718<br>(201) 831-6038 (FAX)<br>karen.ariemma@stryker.com |
### Date Summary Prepared: May 3, 2005
The Triathlon® X3TM UHMWPE Postcrior Stabilized and Cruciate Retaining tibial inserts and the Triathlon® X31™ UHMWPE Patellar components are intended to be used with the cemented Triathlon® PS and CR femoral components and cemented Triathlon® Primary Cemented Tibial Tray in primary or revision total knee arthroplasty. The Triathlon® X3™ UHMWPE Patellar components are intended to be used with the femoral components of the previously released Duracon® Total Knee System The Triathlon® PS Total Knee System is intended to be used in situations where the posterior cruciate ligament is absent, or cannot be preserved. The Triathlon® CR Total Knee System is intended to accommodate the posterior cruciate ligament (PCL) if is present. The all polyethylene Triathlon® X3™ UHMWPE Patellar components are intended for implantation with bone cement only.
### Indications:
- · Painful, disabling joint disease of the knee resulting from: noninflammatory degenerative joint disease (including osteoarthritis, traumatic arthritis or avascular necrosis) or, rheumatoid artlritis.
- · Post-traumatic loss of knee joint configuration and function.
- · Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
- · Revision of previous unsuccessful knee replacement or other procedure.
- · Fracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniques.
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K051146 (pg. 2 of 2)
Triathlon® X3™ UHMWPE Tibial and Patellar Components
# Additional Indications for Posterior Stabilized Components:
- · Ligamentous instability requiring implant bearing surface geometries with increased constraint.
- · Absent or non-functioning posterior cruciate ligament.
## Contraindications
- Any active or suspected latent infection in or about the knee joint. .
- · Distant foci of infection which may cause hematogenous spread to the implant site.
- · Any mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in postoperative care.
- · Bone stock compromised by disease, infection or prior implantation that cannot provide adequate support and/or fixation to the prosthesis.
- · Skeletal immaturity.
- · Severe instability of the knee joint secondary to the absence of collateral ligament integrity and function.
- Obesity. An overweight or obese patient can produce loads on the prosthesis that can lead to failure of the fixation of the device or to failure of the device itself.
### Device Description
The device includes tibial and patellar components of a total knee system. These components are used for the replacement of the bearing and/or articulating surfaces of the proximal tibia and patella. Tibial inserts will be made in Cruciate Retaining and Posterior Stabilized designs. Patellar components will be made in both Asymmetric and Symmetric designs.
#### Summary of Data
A risk analysis and research and development testing have been performed to demonstrate equivalence of the subject products to the predicate devices. Testing and analysis includes material properties testing, wear testing, disassembly force evaluation, multi-axis fatigue testing, patella shear testing and finite element modeling of contact stresses.
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH AND HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized symbol that resembles an abstract bird or a series of interconnected human figures.
JUL 1 3 2005
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
Ms. Karen Ariemma Senior Regulatory Affairs Specialist Howmedica Osteonics Corp. 325 Corporate Drive Mahwah, New Jersey 07430
Re: K051146
Trade/Device Name: Triathlon® X3™ UHMWPE Tibial Inserts and Patellar Components Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial, polymer/metal/polymer semi-constrained cemented prosthesis Regulatory Class: II Product Code: JWH Dated: May 3, 2005 Received: May 4, 2005
Dear Ms. Ariemma:
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. 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 (PMA), 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 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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); good manufacturing practice requirements as set north in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
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Page 2 - Ms. Karen Ariemma
This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally 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 contact the Office of Compliance at (240) 276-0210. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, 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/cdrl/industry/support/index.html.
Sincerely vours,
Sincerely yours,
Stypt Curda
Miriam C. Provost, Ph.D.
1 Miriam C. Provost, Ph.D. Acting Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
.. ..
Enclosure
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K051146 (pg. 1 of 2)
#### 510(k) Number (if known): _
Device Name: Triathlon® Knee System
Indications for Use:
The Triathlon® X3™ UHMWPE Posterior Stabilized and Cruciate Retaining tibial inserts and the Triathlon® X3™ UHMWPE Patellar components are intended to be used with the cemented Triathlon® PS and CR femoral components and cemented Triathlon® Primary Cemented Tibial Tray in primary or revision total knee arthroplasty. The Triathlon® X3™ UHMWPE Patellar components are intended to be used with the femoral components of the previously released Duracon® Total Knee System The Triathlon® PS Total Knee System is intended to be used in situations where the posterior cruciate ligament is absent, or cannot be preserved. The Triathlon CR Total Knee System is intended to accommodate the posterior cruciate ligament (PCL) if it is present. The all polyethylene Triathlon® X3™ UHMWPE Patellar components are intended for implantation with bone cement only.
#### Indications:
- · Painful, disabling joint disease of the knee resulting from: noninflammatory degenerative joint disease (including osteoarthritis, traumatic arthritis or avascular necrosis) or, theumatoid arthritis.
- · Post-traumatic loss of knee joint configuration and function.
- · Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
- · Revision of previous unsuccessful knee replacement or other procedure.
- · Fracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniques.
#### Additional Indications for Posterior Stabilized Components:
- · Ligamentous instability requiring implant bearing surface geometries with increased constraint.
- · Absent or non-functioning posterior cruciate ligament.
#### Contraindications
- · Any active or suspected latent infection in or about the knee joint.
- · Distant foci of infection which may cause hematogenous spread to the implant site.
- · Any mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in postoperative care.
- · Bone stock compromised by disease, infection or prior implantation that cannot provide adequate support and/or fixation to the prosthesis.
(Division Sign-Off)
Division of General, Restorative.
and Neurological Devices
Page 1 of 2
510(k) Number
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K051146 (pg. 2 of 2)
- · Skeletal immaturity.
- · Severe instability of the knee joint secondary to the absence of collateral ligament integrity and function.
- · Obesity. An overweight or obese patient can produce loads on the prosthesis that can lead to failure of the fixation of the device or to failure of the device itself.
Prescription Use X (Per 21 CFR 801.109)
OR
Over-the-Counter Use***_***__
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED) Concurrence of CDRH, Office of Device Evaluation (ODE)
> Page of
Stye Rurde
(Division Sign-Off) Division of General, Restorative, and Neurological Devices
**510(k) Number** K051146
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.