K013031 · Sulzer Orthopedics, Inc. · KRO · Dec 7, 2001 · Orthopedic
Device Facts
Record ID
K013031
Device Name
MOST OPTIONS SYSTEM
Applicant
Sulzer Orthopedics, Inc.
Product Code
KRO · Orthopedic
Decision Date
Dec 7, 2001
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 888.3510
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
The MOST System is intended to replace the proximal, distal or total femur and/or the proximal tibia, especially in cases that require extensive resection and restoration. Replacement of the distal femur would also include replacement of the proximal tibia and possible resurfacing of the patella, if necessary. Proximal femoral replacement components are available for press-fit or cemented applications. Components used for replacement of the distal femur and proximal tibia are available in a variety of sizes. Specific diagnostic indications for use of the MOST include: - metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, bone tumors) and trauma requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur and/or proximal tibia; - patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., avascular necrosis, osteoarthritis and inflammatory (IJD), e.g. rheumatoid arthritis, requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur and/or proximal tibia; and - revision cases requiring resection(s) and replacement(s) of the proximal, distal or total femur and/or proximal tibia.
Device Story
Modular orthopedic prosthesis system for extensive femoral/tibial resection and reconstruction; oncology and revision applications. Components include distal femoral replacements (condylar/hinged), proximal femoral replacements, proximal tibial replacements, intramedullary stems with Cancellous Structured Titanium (CSTi) coating, and all-poly patella. System utilizes hinge-type mechanism for femorotibial articulation. Implantation performed by orthopedic surgeons in clinical/surgical settings. Modularity allows intraoperative adjustment for bone loss. Provides structural restoration of limb; enables joint function in patients with severe bone loss or malignancy.
Clinical Evidence
No clinical data provided; substantial equivalence is based on bench testing and design comparison to legally marketed predicate devices.
Technological Characteristics
Modular orthopedic prosthesis; materials include metal (CSTi coated titanium) and polymer components. Features hinge-type articulation mechanism, intramedullary stems, and modular segments for varying resection lengths. Designed for cemented or press-fit application.
Indications for Use
Indicated for patients requiring extensive resection and replacement of proximal, distal, or total femur and/or proximal tibia due to metastatic bone disease (e.g., osteosarcoma, chondrosarcoma, giant cell tumor), trauma, non-inflammatory degenerative joint disease (e.g., avascular necrosis, osteoarthritis), inflammatory joint disease (e.g., rheumatoid arthritis), or revision surgery.
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).
Predicate Devices
Sulzer Orthopedics MOST™ System
Johnson & Johnson S-ROM® Noiles™ Rotating Hinge Knee System
Howmedica Osteonics® Modular Rotating Hinge Knee (MRS)
Submission Summary (Full Text)
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K013031
page 1 of 2
#### 510(k) SUMMARY
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 Sulzer Orthopedics MOST Options™ System
| Manufacturer: | Sulzer Orthopedics Inc.<br>9900 Spectrum Drive<br>Austin, Texas 78717<br>(512) 432-9900 |
|-------------------------|------------------------------------------------------------------------------------------------------------------------|
| Date: | September 7, 2001 |
| Contact Person: | Frances E. Harrison, RAC<br>Senior Regulatory Affairs Specialist |
| Classification Name: | Knee joint femorotibial metal/polymer constrained cemented<br>prosthesis - 21 CFR Part 888.3510 |
| | Hip joint metal/ceramic/polymer semi-constrained cemented or<br>nonporous uncemented prosthesis - 21 CFR Part 888.3353 |
| Common/Usual Name: | Total Hinged Knee for Total Knee Replacement<br>Femorotibial Prosthesis |
| Trade/Proprietary Name: | MOST Options™ System (MOST) |
### PRODUCT DESCRIPTION
The MOST Options System (MOST) is used for the replacement of the proximal, distal or total femur and/or the proximal tibia. Replacement of the distal femur would also include replacement of the proximal tibia and possible resurfacing of the patella, if necessary. Unlike primary hip and knee systems, this system can be used where extensive femoral and/or tibial resection and restoration is required (e.g., oncology cases). Modularity of the system allows for the resection of varying amounts of the femur and the proximal tibia (and patella, if necessary) before implantation. A total replacement is possible in cases where no part of the femur can be salvaged. Moreover, the system provides additional options for revision or severe bone loss of the tibia. The components of the MOST System include:
- . a distal femoral replacement (Condylar End or Hinged Femur) which mates with a tibial component via a hinge type mechanism (Hinge-Kit or 4mm Hinge Kit):
- a proximal femur replacement that is available in two designs to address the . presence or absence of the greater trochanter;
- intramedullary (I/M) stems with Cancellous Structured Titanium™ (CSTi™) and . MOST segments which will be used in conjunction with the proximal and distal femoral replacements, the Proximal Tibia and the MOST Revision Stem Adapter;
- an all poly patella; ●
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- a proximal tibia replacement (Proximal Tibia or Hinged Tibia) which mates with the . Proximal Tibia Insert and Hinged Tibia Insert, respectively and features a distal female taper for attachment of a MOST Revision Stem Adapter, Sulzer Revision Stems or Hinged Tibia Stem Plug (Hinged Tibia only);
- femoral and tibial spacers for use in conjunction with the Hinged Femur and Hinged . Tibia, respectively to augment uni-compartmental or bi-compartmental defects; and
- revision stem adapter with and without CSTi coating used to convert the MOST . taper to the Sulzer taper.
## SPECIFIC DIAGNOSTIC INDICATIONS
Components of the MOST System are intended to replace the proximal, distal or total femur and/or the proximal tibia, especially in cases that require extensive resection and restoration. Specific diagnostic indications for use of the MOST include:
- metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, bone . tumors ) and trauma requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur and/or proximal tibia;
- patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., . avascular necrosis, osteoarthritis and inflammatory (IJD), e.g. rheumatoid arthritis, requiring extensive resection(s) and replacement(s) of the proximal and/or distal femur and/or proximal tibia; and
- revision cases requiring resection(s) and replacement(s) of the proximal, distal or total . femur and/or proximal tibia.
#### SUBSTANTIAL EQUIVALENCE
The MOST Options System is similar to the following commercially available devices in terms of materials, general design features, and intended uses:
- Sulzer Orthopedics MOST™ System .
- Johnson & Johnson S-ROM® Noiles™ Rotating Hinge Knee System .
- Howmedica Osteonics® Modular Rotating Hinge Knee (MRS) .
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/2/Picture/13 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three stripes forming its wings and body. The eagle is enclosed in a circle with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
DEC 0 7 2001
Ms. Frances E. Harrison, RAC Senior Regulatory Affairs Specialist Sulzer Orthopedics, Inc. 9900 Spectrum Drive Austin, Texas 78717
Re: K013031
Trade/Device Name: MOST Options System Regulation Number: 21 CFR 888.3510; 21 CFR 888.3353 Regulation Name: Knee joint femorotibial metal/polymer constrained cemented prosthesis; Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis
Regulatory Class: II Product Code: KRO, LZO Dated: September 7, 2001 Received: September 10, 2001
Dear Ms. Harrison:
We have reviewed your Section 510(k) premarket notification of intent to market the device we nave rovious your becemined the device is substantially equivalent (for the indications ferenced above and have sure) to legally marketed predicate devices marketed in interstate for use stated in the enorosals) to 10gains actual device Amendments, or to commerce prior to rias 2011-11-11 in accordance with the provisions of the Federal Food, Drug, de necs that have boon require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The r ou may, mercesses maines 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 If your device is olassined (600 a00 voyals. Existing major regulations affecting your device can may be subject to back as back as a submit ons, 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 I lease of advised that I Drivisan that your device complies with other requirements of the Act that I Dr Has made a wond regulations administered by other Federal agencies. You must of any I vith 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 OF IT in the quality systems (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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This letter will allow you to begin marketing your device as described in your Section 510(k) This letter will anow you to begin maing of substantial equivalence of your device to a legally premaired notification. The PDF intelling of easification 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 and IT you desire specific ad roo for your witto diagnostic devices), please contact the Office of additionally 21 CHC Far 007.10 Tor questions on the promotion and advertising of Compliance at (301) 594-1699 of Compliance at (301) 594-4639. Also, please note the your devices, proced volisbranding by reference to premarket notification" (21CFR Part 807.97). regulation on this contrass on your responsibilities under the Act may be obtained from the Outcr general miormation turers, 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/cdrh/dsma/dsmamain.html
Sincerely yours,
Sincerely yours,
Mark McMillan
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): | K013031 |
|---------------------------|-------------|
| Device Name: | MOST System |
# Indications for Use:
The MOST System is intended to replace the proximal, distal or total femur and/or The MOST System is intendou to rep that require extensive resection and the proximal tibla, especially in odoco the rouve also include replacement of the restoration. Replacement of the usities with neelssary Proximal femoral
proximal tibia and possible resurfacing of the patella, if necessary Proximal femoral proximal tible and possible for press-fit or cemented applications.
replacement components are available for press-fit or cement within are replacement components are available in a proximal tible are Components used for replacemont of the distances for use of the MOST include:
- metastatic diseases (e.g., osteosarcomas, chondrosarcomas, giant cell tumors, 1. metastatic discases (c.g., octoboarders), and replacement(s) of the proximal and/or distal femur and/or proximal tibia;
- patient conditions of non-inflammatory degenerative joint disease (NIDJD), 2. patient conditions of non inflammatory and inflammatory (IJD), e.g. rheumatoid e.g., avascular necrosis, octobar.mn.org.inn.its) and replacement(s) of the proximal and/or distal femur and/or proximal tibia; and
- revision cases requiring resection(s) and replacement(s) of the proximal, distal 3. or total femur and/or proximal tibia.
# (PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation(ODE)
for Mark N. Melkerson
(Division Sign-Off)
Division of Ge
and Neurologic Devices
510(k) Number K013031
Prescription Use X OR Over-the Counter Use **__**
(Optional Format 1-2-96)
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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.
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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
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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.