ITOTAL CRUCIATE RETAINING (CR) KNEE REPLACEMENT SYSTEM
Applicant
Conformis, Inc.
Product Code
JWH · Orthopedic
Decision Date
Apr 19, 2012
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 888.3560
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
The iTotal® CR Knee Replacement System (iTotal CR KRS) is intended for use as a total knee replacement in patients with knee joint pain and disability whose conditions cannot be solely addressed by the use of a prosthetic device that treats only one or two of the three knee compartments, such as a unicondylar, patello-femoral or bi-compartmental prosthesis. The indications for use include : - Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid arthritis or osteonecrosis of the knee. - Post traumatic loss of joint function. - Moderate varus, valgus or flexion deformity in which the ligamentous structures can be returned to adequate function and stability. - Failed osteotomies, hemiarthoplasties, and unicondylar, patello-femoral or bi-compartmental implants. The iTotal CR KRS is intended for cemented use only.
Device Story
The iTotal CR KRS is a patient-specific, tricompartmental, posterior cruciate ligament (PCL) retaining, semi-constrained cemented knee replacement system. Input data consists of patient CT or MR scans. Proprietary and off-the-shelf software processes these images to design patient-specific implants and ancillary surgical instruments (nylon jigs) that match individual patient anatomy. The system comprises a CoCrMo femoral component, a CoCrMo metal-backed tibial tray, UHMWPE tibial inserts, and a UHMWPE patellar component. Used in clinical settings by orthopedic surgeons, the patient-specific instruments assist in intra-operative component positioning and bone marking/cutting. The device aims to provide a bone-preserving approach for patients with severe knee pain or disability. Clinical benefit is derived from the patient-specific fit, which addresses geometric and anatomic requirements. The modified device features an updated tibial interlock design (double undercut with central spine) compared to the predicate.
Clinical Evidence
No clinical data was required to demonstrate substantial equivalence. Evidence is based on non-clinical laboratory testing, specifically tibial tray/insert interlock assembly/disassembly testing and cadaveric design validation.
Indicated for patients with knee joint pain and disability requiring total knee replacement due to osteoarthritis, traumatic arthritis, rheumatoid arthritis, osteonecrosis, post-traumatic loss of function, or failed prior partial/bi-compartmental implants. Suitable for moderate varus, valgus, or flexion deformity where ligamentous stability is achievable. Contraindicated for conditions treatable by unicondylar or patello-femoral prostheses alone.
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
iTotal Cruciate Retaining Knee Replacement System (K094050)
iTotal Cruciate Retaining Knee Replacement System (K103117)
iTotal Cruciate Retaining Knee Replacement System (K112780)
Submission Summary (Full Text)
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# 1|5
| K120316 | #/5 APR 19 2012 |
|--------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 510(K) SUMMARY | 4/13/12 |
| Submitter's Name<br>and Address | ConforMIS Inc.<br>11 North Ave.<br>Burlington, MA 01803 |
| Establishment<br>Registration Number | 3004153240 |
| Date of Summary | January 30, 2012 |
| Contact Person | Amita S. Shah, Vice President, Quality Assurance & Regulatory<br>Affairs |
| Telephone Number | (781) 345-9164 |
| Fax Number | (781) 345-0104 |
| Name of the Device | ConforMIS iTotal® CR Knee Replacement System (iTotal CR<br>KRS) |
| Common or Usual<br>Name | Cruciate Retaining Total Knee Replacement System |
| Classification Name | Knee joint patellofemorotibial polymer/metal/polymer semi-<br>constrained cemented prosthesis |
| Regulation Number<br>Device Classification | 21 CFR 888.3560<br>Product Code:<br>JWH, Knee joint patellofemorotibial polymer/metal/polymer semi-<br>constrained cemented prosthesis.<br>OOG, Knee joint patellofemorotibial polymer/metal/polymer semi-<br>constrained cemented prosthesis.<br>Intended to be used to assist in the implantation of a specific knee<br>arthroplasty device or a set of specific knee arthroplasty devices.<br>Indicated to include guiding alignment, making or establishing cuts,<br>selecting, sizing, attaching, positioning or orienting implant<br>components. |
1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 - 1999 -
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ConforMIS iTotal CR Knee Replacement System
4/13/12
# 510(k) Summary continued
Indications for Use
K120316
The iTotal® CR Knee Replacement System (iTotal CR KRS) is intended for use as a total knee replacement in patients with knee joint pain and disability whose conditions cannot be solely addressed by the use of a prosthetic device that treats only one or two of the three knee compartments, such as a unicondylar, patello-femoral or bi-compartmental prosthesis. The indications for use include :
- t Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid arthritis or osteonecrosis of the knee.
- . Post traumatic loss of joint function.
- Moderate varus, valgus or flexion deformity in which the ♥ ligamentous structures can be returned to adequate function and stability.
- Failed osteotomies, hemiarthoplasties, and unicondylar, . patello-femoral or bi-compartmental implants.
ConforMIS iTotal CR Knee Replacement System (ITOTAL CR
The iTotal CR KRS is intended for cemented use only.
ldentification of the Legally Marketed Device (Predicate Device)
KRS) Device Class: III Product Code: JWH, OOG Regulation Number: 21 CFR 888.3560 510(k) number: K103117,K094050 and K112780
Device Description The iTotal CR Knee Replacement System (hereafter referred to as the "iTotal CR KRS") is a patient specific tricompartmental faceted posterior cruciate ligament (PCL) retaining knee replacement system. The iTotal CR KRS is a semi-constrained cemented knee implant which consists of a femoral, tibial and patellar component. The product design incorporates a bone preserving approach with minimal bone resection of the tibia and femur for the treatment of severe pain and/or disability of a knee damaged by osteoarthritis or trauma.
> Using patient imaging (either CT or MR scans) and a combination of proprietary and off the shelf software a patient-specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component is manufactured from cobalt chromium molybdenum ("CoCrMo") alloy. The tibial component includes a metal tray manufactured from CoCrMo alloy and two polyethylene inserts manufactured
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K120316
ConforMIS iTotal CR Knee Replacement System
4/13/12
from UHMWPE. The patellar component is manufactured from UHMWPE.
For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding the marking of bone before cutting.
The function and general design features of the patient specific ancillary instruments remain similar to those described in the predicate 510k i.e. K094050, K103117 and K112780.
The product subject of this premarket notification is substantially equivalent to the iTotal Cruciate Retaining Knee Replacement System (K094050 cleared September16, 2010, K103117 cleared January 7, 2011 and K112780 cleared December15, 2011) and other currently marketed, cemented total knee replacement systems. The following testing was performed to establish substantial equivalence:
Tibial interlock assembly and disassembly testing -
- Design validation via cadaveric testing
Substantial Equivalence:
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K120316#4/5
### K120316
## ConforMIS iTotal CR Knee Replacement System
4/13/12
## 510(k) Summary continued
### Device Comparison
| | Predicate<br>iTotal CR Knee Replacement<br>System<br>(K103117) | Modified Device<br>iTotal CR Knee Replacement<br>System<br>(This submission) |
|------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| Components | Femoral Component Tibial Implant Metal Backed Tibial Component Patellar component | Femoral Component Tibial Implant Metal Backed<br>Tibial Component Patellar component |
| Materials | Femoral Implant: CoCrMo Metal Backed Tibial Components: Tibial tray: CoCrMo Tibial Inserts: UHMWPE All Polymer Patellar Component:<br>UHMWPE | Femoral Implant: CoCrMo Metal Backed Tibial Components: Tibial tray: CoCrMo Tibial Inserts: UHMWPE All Polymer Patellar Component:<br>UHMWPE |
| Design | Knee joint patellofemorotibial semi-<br>constrained cemented prosthesis | Knee joint patellofemorotibial semi-<br>constrained cemented prosthesis |
| Principle of<br>Operation | Cemented Use fixed Bearing Design | Cemented Use fixed Bearing Design |
| Patient Matched | Yes | Yes |
| Patellar Design/<br>Dimensions | Symmetrical, offered in various sizes | Symmetrical, offered in various sizes |
| Tibial Implant<br>interlock design | Interference fit Anterior lip Tray undercut design | Interference fit Anterior lip Double Undercut with Central Spine |
| Minimum<br>Thickness of<br>Tibial Insert<br>(UHMWPE) | 6 mm | 6 mm |
| Posterior Cruciate<br>Ligament (PCL)<br>Sparing | Yes | Yes |
| Instrumentation | Patient specific Nylon jigs | Patient specific Nylon jigs |
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#### 510(k) Summary continued
Description and Nonclinical Testing: The determination of substantial equivalence Conclusion of for this device was based on a detailed device description. The Testing following non-clinical laboratory testing was performed demonstrating that the device is safe and can be considered substantially equivalent to the predicate device for the intended use: Tibial tray/insert interlock assembly/disassembly testing . Cadaveric testing . Safety and The determination of substantial equivalence for this device was Performance based on a detailed device description. Non-clinical laboratory testing was performed demonstrating that the device is safe and can be considered substantially equivalent to the predicate device for the proposed intended use. Clinical data is not necessary to demonstrate substantial equivalence. Conclusion: Based on the testing conducted it is concluded that the modified device is substantially equivalent to the iTotal Cruciate Retaining Knee Replacement System, K094050 cleared September 16, 2010, K103117 cleared January 7, 2011 and K112780 cleared December15, 2011.
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Image /page/5/Picture/0 description: The image shows a partial view of a logo and some text. The logo is a circular emblem with a stylized image of an eagle or similar bird, surrounded by text that reads "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA". To the right of the logo, the word "DEPART" is visible, suggesting that the image is part of a larger document or graphic.
### DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
Food and Drug Administration 10903 New Hampshire Avenue Document Control Room -WO66-G609 Silver Spring, MD 20993-0002
ConforMIS, Incorporated % Ms. Amita S. Shah 11 North Avenue Burlington, Massachusetts 01803
APR 1.9 2012
Re: K120316
Trade/Device Name: iTotal CR Knee Replacement System Regulation Number: 21 CFR 888.3560
Regulation Name: Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Regulatory Class: Class II Product Code: JWH. OOG Dated: January 30, 2012 Received: February 01, 2012
Dear Ms. Shah:
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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to 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 or uny I ederal the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set
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#### Page 2 - Ms. Amita S. Shah
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.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
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) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.
Sincerely yours,
urs,
Ka
elkerson
Mark N. Melkerson Director Division of Surgical, Orthopedic and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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#### Indications for Use
510(k) Number (if known): K120316
Device Name: iTotal CR Knee Replacement System
Indications for Use:
The iTotal® CR Knee Replacement System (iTotal CR KRS) is intended for use as a total knee replacement in patients with knee joint pain and disability whose conditions cannot be solely addressed by the use of a prosthetic device that treats only one or two of the three knee compartments, such as a unicondylar, patello-femoral or bicompartmental prosthesis. The indications for use include:
- Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid arthritis or . osteonecrosis of the knee.
- Post traumatic loss of joint function.
- Moderate varus, valgus or flexion deformity in which the ligamentous structures can . be returned to adequate function and stability.
- Failed osteotomies, hemiarthoplasties, and unicondylar, patello-femoral or bi-. compartmental implants.
The iTotal CR KRS is intended for cemented use only.
Over-The-Counter Use Prescription Use AND/OR (21 CFR 801 Subpart C) (Part 21 CFR 801 Subpart D) (PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE OF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Oveal
(Division Sign-Off) Division of Surgical, Orthopedic, and Restorative Devices
510(k) Number
Special 510(k) - Modified iTotal® CR Knee Replacement System Page 24 of 86
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.