N-K Flex System: · Components with CSTi porous coating are indicated for uncemented or cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments undergoing primary surgery for rehabilitating knees damaged as a result of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD). · Components without CSTi porous coating are indicated for cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments with conditions of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD), correctable varus-valgus deformity and moderate flexion contracture, or failed previous surgery where pain, deformity or dysfunction persists. · The N-K Flex femoral provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. When used with N-K Flex, NexGen Trabecular Metal™ CR Monoblock, 90-prefix NexGen CR, 00-prefix 10, 12 or 14mm or 90prefix 17 or 20mm Prolong " Highly Crosslinked Polyethylene CR articular surfaces, it is designed for use when load bearing ROM is expected to be less than or equal to 155 degrees. NexGen CR-Flex GSF Femoral Components: · This device is indicated for patients with severe knee pain and disability due to: -Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis. -Collagen disorders, and/or avascular necrosis of the femoral condyle. -Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy. - Moderate valgus, varus, or flexion deformities. - The salvage of previously failed surgical attempts or for a knee in which satisfactory stability in flexion cannot be obtained at the time of surgery. · This device is intended for cemented use only. · Specific uses with CR-Flex GSF femorals: - Provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. - The CR-Flex GSF femoral, when used with 90-prefix NexGen CR articular surfaces, 00-prefix 10, 12 or 14mm or 90-prefix 17 or 20mm Prolong Highly Crosslinked Polyethylene CR articular surfaces, or with Gender Solutions™ Natural-Knee® Flex Congruent articular surfaces, is designed for use with a functional posterior cruciate ligament and when load bearing range of motion (ROM) is expected to be less than or equal to 155 degrees.
Device Story
Semiconstrained, nonlinked condylar knee prosthesis; designed for maximum active flexion of 155 degrees. Femoral components modified to address specific distal femur anatomical features typical of male and female patients. Used by orthopedic surgeons in clinical settings for total knee arthroplasty. Provides increased flexion capability for patients desiring greater range of motion. Benefits include restoration of joint function, pain relief, and correction of deformities. Output is the physical implant system replacing damaged joint surfaces.
Clinical Evidence
No clinical data provided; bench testing only.
Technological Characteristics
Semiconstrained, nonlinked condylar knee prosthesis. Materials include metal and polymer. Features CSTi porous coating for uncemented use or non-coated for cemented use. Designed for 155-degree flexion. Compatible with specific NexGen CR articular surfaces and Prolong Highly Crosslinked Polyethylene.
Indications for Use
Indicated for skeletally mature patients with intact medial/lateral collateral ligaments requiring primary knee surgery for NIDJD or IJD, or salvage of failed prior surgery. Includes patients with severe knee pain/disability due to RA, OA, traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis, or post-traumatic joint loss. Contraindicated if collateral ligaments are not intact.
Regulatory Classification
Identification
A knee joint patellofemorotibial metal/polymer porous-coated uncemented 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 is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra high molecular weight polyethylene tibial bearing is rigidly secured to the metal tibial base plate.
Special Controls
*Classification.* Class II (special controls). The special control is FDA's guidance: “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA.” See § 888.1 for the availability of this guidance.
Predicate Devices
Gender Solutions Natural-Knee Flex System (K070214)
{0}------------------------------------------------
# KO71107 (ps 1 of 3)
### Summary of Safety and Effectiveness
JUL - 6 2007
| Submitter: | Zimmer, Inc.<br>P.O. Box 708<br>Warsaw, IN 46581-0708 |
|---------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Contact Person: | Brandon Hipsher, RAC<br>Senior Associate, Corporate Regulatory Affairs<br>Telephone: (574) 371-8083<br>Fax: (574) 372-4605 |
| Date: | April 18, 2007 |
| Trade Name: | Gender Solutions™ Natural-Knee® Flex System;<br>NexGen® Complete Knee Solution CR-Flex Gender<br>Solutions Female (GSF) Femoral Component |
| Common Name: | Total Knee Prosthesis |
| Classification Name<br>and Reference: | Knee joint patellofemorotibial<br>polymer/metal/polymer semiconstrained cemented<br>prosthesis<br>21 CFR § 888.3560 |
| | Knee joint patellofemorotibial metal/polymer<br>porous-coated uncemented prosthesis<br>21 CFR § 888.3565 |
| Predicate Devices: | Gender Solutions Natural-Knee Flex System,<br>manufactured by Zimmer, Inc., K070214, cleared<br>March 16, 2007.<br>NexGen Knee Gender Solutions Female (GSF)<br>Femoral Components, manufactured by Zimmer,<br>Inc., K060370, cleared April 28, 2006. |
| Device Description: | The Gender Solutions Natural-Knee Flex (N-K<br>Flex) and NexGen CR-Flex GSF components are<br>semiconstrained, nonlinked condylar knee<br>prosthesis that are designed to have a maximum<br>active flexion of 155 degrees. The GSM and GSF<br>femoral component designations indicate that the<br>design of the femoral components has been<br>modified to address specific anatomical features of |
:
. .
{1}------------------------------------------------
Kc71107 (pg. 2 of 3)
the distal femur that can be seen in patients of either gender, but are more typical of male and female patients, respectively.
Intended Use:
N-K Flex System:
- · Components with CSTi porous coating are indicated for uncemented or cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments undergoing primary surgery for rehabilitating knees damaged as a result of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD).
- · Components without CSTi porous coating are indicated for cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments with conditions of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD), correctable varus-valgus deformity and moderate flexion contracture, or failed previous surgery where pain, deformity or dysfunction persists.
- · The N-K Flex femoral provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. When used with N-K Flex, NexGen Trabecular Metal™ CR Monoblock, 90-prefix NexGen CR, 00-prefix 10, 12 or 14mm or 90prefix 17 or 20mm Prolong " Highly Crosslinked Polyethylene CR articular surfaces, it is designed for use when load bearing ROM is expected to be less than or equal to 155 degrees.
NexGen CR-Flex GSF Femoral Components:
- · This device is indicated for patients with severe knee pain and disability due to:
- -Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis.
- -Collagen disorders, and/or avascular necrosis of the femoral condyle.
- -Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy.
{2}------------------------------------------------
K071107 (pg. 3 of 3)
| | - Moderate valgus, varus, or flexion<br>deformities.<br>- The salvage of previously failed surgical<br>attempts or for a knee in which satisfactory<br>stability in flexion cannot be obtained at the<br>time of surgery.<br>• This device is intended for cemented use only.<br>• Specific uses with CR-Flex GSF femorals:<br>- Provides increased flexion capability for<br>patients who have both the flexibility and<br>desire to increase their flexion range.<br>- The CR-Flex GSF femoral, when used with<br>90-prefix NexGen CR articular surfaces, 00-<br>prefix 10, 12 or 14mm or 90-prefix 17 or<br>20mm Prolong Highly Crosslinked<br>Polyethylene CR articular surfaces, or with<br>Gender Solutions™ Natural-Knee® Flex<br>Congruent articular surfaces, is designed for<br>use with a functional posterior cruciate<br>ligament and when load bearing range of<br>motion (ROM) is expected to be less than or<br>equal to 155 degrees. |
|----------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Comparison to Predicate Device: | Except for changes in component compatibility, the<br>subject components are identical to the predicate<br>device. |
| Performance Data (Nonclinical<br>and/or Clinical): | Non-Clinical Performance and Conclusions: |
| | Mechanical testing of the subject devices<br>demonstrates that they are substantially equivalent<br>to the predicate devices. |
| | Clinical Performance and Conclusions: |
| | Clinical data and conclusions were not needed for<br>these devices. |
.
. .
{3}------------------------------------------------
Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three lines representing its wings and head. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
JUL -6 2007
JUL
Zimmer, Inc. % Mr. Brandon Hipsher, RAC Senior Associate, Corporate Regulatory Affairs P.O. Box 708 Warsaw, Indiana 46581
Re: K071107
Trade/Device Name: Gender Solutions™ Natural-Knee® Flex System; NexGen® Complete Knee Solution CR-Flex Gender Solutions™ Female (GSF) Femoral Component Regulation Number: 21 CFR 888.3565 Regulation Name: Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis Regulatory Class: Class II Product Codes: MBH, JWH Dated: June 1, 2007 Received: June 4, 2007
Dear Mr. Hipsher:
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. Iisting 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
{4}------------------------------------------------
Page 2 - Mr. Brandon Hipsher, RAC
forth 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. 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) 276-0120. 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 toll-free number (800) 638-2041 or (240) 276-3150 or the Internet address http://www.fda.gov/cdrh/industry/support/index.html.
Sincerely yours, Mark N. Melkerson Director Division of General, Restorativ and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
{5}------------------------------------------------
## K071107
#### Indications for Use
#### 510(k) Number (if known):
#### Device Name:
Gender Solutions™ Natural-Knee® Flex System; NexGen® Complete Knee Solution CR-Flex Gender Solutions™ Femoral Component
#### Indications for Use:
Gender Solutions "Natural-Knee" Flex System:
- · Components with CST porous coating are indicated for uncemented use in skeletally mature individuals with intact medial and lateral collateral ligaments undergoing primary surgery for rehabilitating knees damaged as a result of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD).
- · Components without CSTi are indicated for cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments with conditions of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (ID), correctable varus-valgus deformity and moderate flexion contracture, or failed previous surgery where pain, deformity or dysfunction persists.
- · The N-K Flex femoral provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. When used with N-K Flex, NexGen Trabecular Metal" CR Monoblock, 90-prefix NexGen CR, 00-prefix 10, 12 or 14mm or 90-prefix 17 or 20mm Prolong "Highly Crosslinked Polyethylene CR articular surfaces, it is designed for use when load bearing ROM is expected to be less than or equal to 155 degrees.
NexGen® Complete Knee Solution CR-Flex Gender Solutions™ Femoral Component:
- · This device is indicated for patients with severe knee pain and disability due to:
- Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis,
- Collagen disorders, and/or avascular necrosis of the femoral condyle.
- Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy.
- Moderate valgus, varus, or flexion deformities.
- The salvage of previously failed surgical attempts or for a knee in which satisfactory stability in flexion cannot be obtained at the time of surgery.
- · This device is intended for cemented use only.
- · Specific uses with CR-Flex GSF femorals:
- Provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range.
- The CR-Flex GSF femoral, when used with 90-prefix NexGen CR articular surfaces, 00-prefix 10, 12 or 14mm or 90-prefix 17 or 20mm Prolong Highly Crosslinked Polyethylene CR articular surfaces, or with Gender Solutions Natural-Knee Flex Congruent articular surfaces, is designed for use with a functional posterior cruciate ligament and when load bearing range of motion (ROM) is expected to be less than or equal to 155 degrees.
Prescription Use X (Part 21 CFR 801 Subpart D) AND/OR
Over-The-Counter Use (21 CFR 807 Subpart C)
(Please do not write below this line - Continue on another page if needed)
Concurrence of CDRH, Office of Device Evaluation (ODE)
| (Division Sign-Off)<br>Division of General, Restorative,<br>and Neurological Devices | Page 1 of 1 |
|--------------------------------------------------------------------------------------|-------------|
|--------------------------------------------------------------------------------------|-------------|

| 510(k) Number | K071107 |
|---------------|---------|
|---------------|---------|
Predicate graph will load when search results are available.
Embedding visualization will load when search results are available.
PDF viewer will load when search results are available.
Loading panels...
Select an item from Submissions
Click any panel, subpart, regulation, product code, or device to see details here.
Section Matches
Results will appear here.
Product Code Matches
Results will appear here.
Special Control Matches
Results will appear here.
Loading collections...
Loading
My Alerts
You will receive email notifications based on the filters and frequency you set for each alert.
Sort by:
Create Alert
Search Filters
Agent Token
Create a read-only bearer token for Claude, ChatGPT, or other agents that can call HTTP APIs.
Copy this now. It will not be shown again.
Connected apps
Apps you authorized through browser sign-in. Disconnecting revokes their access immediately.
Learn the FDA Browser
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.