The Modular Replacement System (MRS -- found substantially equivalent in K952970, K965164 and K972 al) has been successfully used in clinical situations where there is extensive bone loss due to tumor resection, and/or failed previous prosthesis, or trauma. These components can be used to replace the proximal femur, the distal femur, the proximal tibia, or to reconstruct the total femur in extreme clinical situations.
Device Story
Modular Replacement System (MRS) Cemented Stems are orthopedic implants used for segmental bone replacement in the proximal femur, distal femur, or proximal tibia. Stems are available in standard and small configurations, with straight or curved geometries and optional porous coating. Devices are implanted by orthopedic surgeons in clinical settings to address bone loss from tumor resection, trauma, or revision of failed prostheses. Stems utilize a Morse taper (2 degrees 52 minutes) to connect to other MRS/GMRS system components and are secured using bone cement. A recessed hole at the distal end allows for an optional cement centralizer. By providing structural support and restoring skeletal integrity, the system aims to improve patient mobility and function following extensive bone loss.
Clinical Evidence
Bench testing only. No clinical data provided. Substantial equivalence is supported by engineering analysis.
Technological Characteristics
Cemented femoral/tibial stems; Morse taper connection (2 degrees 52 minutes); available in straight/curved configurations; lengths 102mm-203mm; distal diameters 8mm-17mm; seat diameters 24mm-36mm; optional porous coating; intended for use with bone cement.
Indications for Use
Indicated for femoral and/or proximal tibial replacement in patients with extensive bone loss due to trauma, failed previous prosthesis, or tumor resection. Contraindicated in patients with pathological fracture, overt infection, inopportune biopsy incision, rapid disease progression, or neuromuscular disorders creating unacceptable risk of instability or fixation failure.
Regulatory Classification
Identification
A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits translation or rotation in one or more planes and has components that are linked together or affined. This generic type of device includes prostheses composed of a ball-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a ball at the head of a column rising from the stemmed tibial component. The ball, the column, the tibial plateau, and the stem for fixation of the tibial component are made of an alloy, such as cobalt-chromium-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the femoral component's flat outer surface. The flat outer surface of the tibial component abuts both a reciprocal flat surface within the cavity of the femoral component and flanges on the femoral component designed to prevent distal displacement. The stem of the femoral component is made of an alloy, such as cobalt-chromium-molybdenum, but the socket of the component is made of ultra-high molecular weight polyethylene. The femoral component has metallic runners which align with the ultra-high molecular weight polyethylene tracks that press-fit into the metallic tibial component. The generic class also includes devices whose upper and lower components are linked with a solid bolt passing through a journal bearing of greater radius, permitting some rotation in the transverse plane, a minimal arc of abduction/adduction. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).
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Modular Replacement System Cemented Stems Confidential
510(k) Premarket Notification
ん
| Confidential | | K040749<br>page 1 of |
|------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
| JUN 17 2004 | 510(k) Summary | |
| Submission Information | | |
| Name and Address of Sponsor: | Howmedica Osteonics Corp.<br>325 Corporate Drive<br>Mahwah, New Jersey 07430 | |
| For Information contact: | Margaret F. Crowe<br>Regulatory Affairs Consultant<br>Howmedica Osteonics Corp.<br>325 Corporate Drive<br>Mahwah, New Jersey 07430 | |
| Device Identification | | |
| Proprietary Name: | Modular Replacement System Cemented Stems | |
| Common Name: | Proximal Femoral Replacement<br>and<br>Modular Rotating Hinge Knee | |
| Classification Name and Reference: | Prosthesis, Hip, Semi-constrained Metal/Polymer<br>Porous Uncemented<br>21 CFR §888.3358<br>and<br>Knee joint femorotibial metal/polymer<br>constrained cemented prosthesis<br>21 CFR §888.3510 | |
| Proposed Regulatory Class: | Class II | |
| Device Product Code: | OR(87) LPH and KRO | |
### Intended Use
The Modular Replacement System (MRS -- found substantially equivalent in K952970, K965164 and K972 al) has been successfully used in clinical situations where there is extensive bone loss due to tumor resection, and/or failed previous prosthesis, or trauma. These components can be used to replace the proximal femur, the distal femur, the proximal tibia, or to reconstruct the total femur in extreme clinical situations.
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Modular Replacement System Cemented Stems ____________________________________________________________________________________________________________________________________ Confidential
page 20f
040749
It is the intention of Howmedica Osteonics Corp. to expand the indications for use of the standard Proximal/Distal Femoral Stems to include use in the proximal tibia. In order to accomplish this change, the product label for these stems will change to "Cemented Stem". In addition, a minor design change is being made - the diameter at the base of the male taper of these stems will be changed from 28mm to provide a minimal transition when assembled to a variety of components.
Likewise, it is the intention of Howmedica Osteonics Corp. to expand the indications for use for the Small Distal Femoral Stems to include use in the proximal tibia, and to expand the clinical situations where this product can be used to include failed previous prosthesis and trauma. In order to accomplish this change, the product label description for these devices will be changed to "Small Cemented Stem". In addition, the diameter at the base of the male taper of these small stems will be changed from 24mm to provide a minimal transition when assembled to a variety of components.
All of the stems currently cleared for use in the distal femur would also be available for use in the proximal tibia. All of these stems would be indicated for use with the other segments of the Modular Replacement System (MRS) and/or Global Modular Replacement System (GMRS™) in the treatment of extensive bone loss due to tumor resection, and/or failed previous prosthesis, or trauma. These stems are intended for use with bone cement.
Specific indications for these MRS Cemented Stems are discussed below:
#### Indications
Femoral and/or proximal tibial replacement due to
- . Trauma
- Failed previous prosthesis .
- Tumor resection .
#### Contraindications
- As related to Bone Tumors A.
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510(k) Premarket Notificati
Not all bone tumors may be treated successfully by segmental resection. Any condition that may have already resulted in either local or distant spread of the tumor may be a contraindication. Examples of such conditions include:
- pathological fracture; .
- overt infection; .
- inopportune placement of biopsy incision; and, .
- rapid disease progression beyond a respectable margin. .
- As related to Failed Previous Prosthesis and Trauma B.
- Any active or suspected latent infection in or about the hip joint. .
- Any mental or neuromuscular disorder which would create an unacceptable risk of . prosthesis instability, prosthesis fixation failure, or complication in postoperative care.
- Bone stock compromised by disease, infection, or prior implantation that cannot . provide adequate support and fixation of the prosthesis.
## Device Description
The following configurations of MRS Cemented Stems will be available:
## Standard Cemented Stems:
- Straight stem with 40mm porous coated body distal diameters/seat diameters are ◆ 11mm/24mm, 13mm/28mm, 15mm/32mm, 17mm/36mm - 127mm in length
- Straight stem without body distal diameters/seat diameters are 11mm/24mm, . 13mm/28mm, 15mm/32mm, 17mm/36mm - 127mm in length
- Curved stem with 40mm porous coated body distal diameters/seat diameters are . 11mm/24mm, 13mm/28mm, 15mm/32mm, 17mm/36mm - 127mm in length
- Curved stem without body distal diameters/seat diameters are 11mm/24mm, . 13mm/28mm, 15mm/32mm, 17mm/36mm - 127mm in length
- Curved stem with 40mm porous coated body distal diameters/seat diameters are . 11mm/24mm, 13mm/28mm, 15mm/32mm, 17mm/36mm - 203mm in length
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40749 page 4 of 4
Modular Replacement System Centeried Sions ___________________________________________________________________________________________________________________________________ Confidential
510(k) Premarket Notification
- Curved stem without body distal diameters/seat diameters are 11mm/24mm, . 13mm/28mm, 15mm/32mm, 17mm/36mm - 203mm in length
Standard cemented femoral stems will be used in the proximal femur, distal femur, and proximal tibia. These stems may be used with the standard and small distal femoral component, and standard and small proximal tibial component of the MRS and/or GMRS™ systems.
# Small Cemented Stems:
- Straight stem with 40mm porous coated body distal diameters/seat diameters are . 8mm/24mm, 9mm/24mm, 10mm/24mm - 102mm in length
- Straight stem without body distal diameters/seat diameters are 8mm/24mm, . 9mm/24mm, 10mm/24mm - 102mm in length
- Curved stem with 40mm porous coated body distal diameters/seat diameters are . 8mm/24mm, 9mm/24mm, 10mm/24mm - 102mm in length
- Curved stem without body distal diameters/seat diameters are 8mm/24mm, . 9mm/24mm, 10mm/24mm - 102mm in length
These stems may be used with the small Distal Femoral component, and small proximal tibial component of the MRS and/or GMRSTM systems.
All of the stems utilize a Morse taper to connect to the proximal femoral/distal femoral or proximal tibial components. The taper angle is 2 degrees 52 minutes. At the distal end of the larger stems is a recessed hole to allow the optional use of a cement centralizer.
Equivalent products include the existing MRS Proximal Femoral Stems, Distal Femoral Stems and Proximal Tibial Stems.
An engineering analysis was presented to support a claim of substantial equivalence to the predicate devices.
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Image /page/4/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract symbol that resembles an eagle or bird in flight, composed of three curved lines.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
JUN 1 7 2004
Ms. Margaret F. Crowe Regulatory Affairs Consultant Howmedica Osteonics Corp. 325 Corporate Drive Mahwah, New Jersey 07430
Re: K040749
Ko40747
Trade/Device Name: Modular Replacement System (MRS) Cemented Stems Regulation Number: 21 CFR 888.3510 Regulation Name: 21 CFTC 000.5010
Regulation Name: Knee joint femorotibial metal/polymer constrained cemented prosthesis Regulatory Class: II Product Code: KRO Dated: March 19, 2004 Received: March 23, 2004
Dear Ms. Crowe:
We have reviewed your Section 510(k) premarket notification of intent to market the device wt have teviewed your becarel be device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate 101 use stated in the encreation of tegally to regists of the Medical Device Amendments, or to conninered pror to rilly 20, 1978, is accordance with the provisions of the Federal Food, Drug, de necs that have boon require approval of a premarket approval application (PMA). and Cosmetic Act (710) market the device, subject to the general controls provisions of the Act. The 1 ou may, therefore, market the Act include requirements for annual registration, listing of general controls provision 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 rr your device is olassified (600 world). Existing major regulations affecting your device can
may be subject to such additional controls. Existing major regulations and the may be subject to such additions, Title 21, Parts 800 to 898. In addition, FDA may be found in the Our cements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean I lease be advised that I Dri 8 issuance or with other requirements of the Act that I DIT has made a acterimations administered by other Federal agencies. You must of any it catal statuter and regainents, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set CI IT rail 607); adomig (21 CFR Part 820); and if applicable, the electronic forth in the quality bytellis (Sections 531-542 of the Act); 21 CFR 1000-1050.
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Page 2 - Ms. Margaret F. Crowe
This letter will allow you to begin marketing your device as described in your Section 510(k) I his letter witi anow you to begin maileans your device of your device to a legally premaired notincation. The PDF intellig of the mailing of 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 If you desire spocitie acritor for your 201) 594-4659. Also, please note the regulation entitled, Connect the Office of Court Courtemarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small other general informational and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html
Sincerely yours,
Sincerely yours,
Mark A. Mulkerson
Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Number (if known): _ KOYO749
Device Name:___Modular Replacement System (MRS) Cemented Stems
Femoral and/or proximal tibial replacement due to
- Trauma .
- Failed previous prosthesis .
- Tumor resection .
(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
OR Prescription Use
Over-The-Counter Use__________________________________________________________________________________________________________________________________________________________ (Per 21 CFR 801.109) (Optional Format 1-2-96)
Mark A. Millheim
ថ្វើក្រោ sion Division of General, Restorative, and Neurological Devices
KO4 6799 510(k) Number_
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.
