The iTotal Identity® Cruciate Retaining (CR) Knee Replacement System (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, patellofemoral 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, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.
· Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

The iTotal PS Knee Replacement System (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, patellofemoral or bicompartments.

The Indications for Use include:

· Painful joint disease due to osteoarthritis, traumatoid arthritis, polyarthritis, polyarthritis or osteonecrosis of the knee.

· Post traumatic loss of joint function.

· Moderate varus, valgus or flexion deformity.
· Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.

· Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

Device Description

iTotal Identity® Cruciate Retaining (CR) Knee Replacement System (KRS) and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System (KRS) are patient specific tri-compartmental faceted knee replacements systems. The iTotal Identity CR KRS is a faceted posterior cruciate ligament retaining knee replacement system. It is a semi-constrained, cemented knee implant which consists of femoral, tibial, and patellar components. iTotal Identity® PS KRS is a semi-constrained, cemented knee implant consisting of femoral, tibial, patellar and articular tibial insert components.

Using patient imaging 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 and tray keel stem extension manufactured from titanium (Ti6AL4V-ELI) alloy, a tibial tray keel cap manufactured from polyethylene (UHMWPE) and either one or two polyethylene inserts (Two piece is CR only). The polyethylene inserts may be manufactured from either UHMWPE or iPoly® XE (a highly cross-linked vitamin E stabilized UHMWPE). The patellar component is provided in either a round or oval dome shape and may be manufactured from either UHMWPE or iPoly® XE.

For user convenience, single-use, patient-specific ancillary orthopedic manual surgical instruments designed for use with the proposed iTotal Identity® CR KRS or iTotal Identity® PS KRS are provided to assist in the positioning of the total knee replacement components intraoperatively and in guiding the cutting of bone. In addition, reusable orthopedic manual surgical instruments are provided separately.

AI/ML Overview

The provided document is a 510(k) summary for a medical device (Conformis iTotal Identity® Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System). It describes a modification to an already cleared device, specifically changing the raw material for the patellar component and tibial inserts.

*Crucially, this document does not describe an AI/ML-based device or a study involving human readers or ground truth established by experts in an AI/ML context.

Therefore, I cannot extract the information requested regarding:

Acceptance criteria related to AI/ML device performance metrics (e.g., sensitivity, specificity, AUC).
Sample sizes for test sets where AI performance is evaluated against ground truth.
Number of experts for ground truth establishment or their qualifications.
Adjudication methods for test sets.
MRMC comparative effectiveness studies or effect sizes for human reader improvement with AI.
Standalone algorithm performance.
Type of ground truth (expert consensus, pathology, outcomes data).
Training set sample size or ground truth establishment for the training set.

What the document does describe regarding "acceptance criteria" and "study that proves the device meets the acceptance criteria" relates to the material equivalency of a knee implant component, not an AI system.

Here's a breakdown of what can be gleaned from the document regarding the device and its "proof":

1. Acceptance Criteria and Reported Device Performance (related to material equivalency):

The document states:

"The difference between the subject raw material and the predicate raw material is that the subject raw material will not be mechanically annealed."
Acceptance Criteria (implicit for material equivalency): The new raw material (iPoly® XE without mechanical annealing) must have "no statistically significant impact on the physical or chemical properties when compared to the predicate material" and "raises no new issues regarding safety or effectiveness."
Reported Device Performance (for material equivalency): "Testing to compare the subject raw material to the predicate material was conducted." and "The absence of an annealing step in the processing of the raw material does not have a statistically significant impact on the physical or chemical properties when compared to the predicate material and supports that the materials are equivalent."

2. Sample Size and Data Provenance:
Not applicable in the context of AI/ML. The "data" refers to physical and chemical properties of materials. The document does not specify the number of material samples tested or their provenance in terms of country or retrospective/prospective collection, as this is a material science characterization, not a clinical data study for AI.

3. Number of Experts and Qualifications for Ground Truth:
Not applicable. Ground truth here is established by material science testing and characterization, not expert human review of medical images for diagnostic purposes.

4. Adjudication Method:
Not applicable. This is not a study requiring adjudication of expert opinions.

5. MRMC Comparative Effectiveness Study:
Not applicable. No AI component or human reader study described.

6. Standalone Performance:
Not applicable. This is not an AI algorithm.

7. Type of Ground Truth Used:
The "ground truth" here is the established physical and chemical properties of the predicate material, against which the new material is compared. This is based on material characterization standards and laboratory testing, not medical expert consensus, pathology, or outcomes data in a clinical sense.

8. Sample Size for Training Set:
Not applicable. There is no training set for an AI/ML model.

9. How the Ground Truth for the Training Set Was Established:
Not applicable. There is no training set.

In summary, the provided text is for a material modification to a knee implant, demonstrating substantial equivalence through material testing, not for an AI/ML medical device. Therefore, most of the requested information regarding AI/ML device acceptance criteria and study methodology is not present in this document.

Summary

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December 22, 2020

Image /page/0/Picture/1 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

Conformis Inc. Mary Kruitwagen Sr. Regulatory Affairs Specialist 600 Technology Park Drive, 4th Floor Billerica, Massachusetts 01821

Re: K203447

Trade/Device Name: iTotal Identity® Cruciate Retaining (CR) Knee Replacement System, iTotal Identity® Posterior Stabilizing (PS) Knee Replacement System Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial polymer semi-constrained cemented prosthesis Regulatory Class: Class II Product Code: JWH, OOG, OIY Dated: November 19, 2020 Received: November 23, 2020

Dear Mary Kruitwagen:

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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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 comply with all the Act's

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requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

For Ting Song, Ph.D., R.A.C. Assistant Director DHT6A: Division of Joint Arthroplasty Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known)

K203447

Device Name

iTotal Identity® Cruciate Retaining Knee Replacement System

Indications for Use (Describe)

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, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.
· Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

Type of Use (Select one or both, as applicable)

Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

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Indications for Use

510(k) Number (if known)

K203447

Device Name

iTotal Identity® Posterior Stabilized Knee Replacement System

Indications for Use (Describe)

The Indications for Use include:

· Painful joint disease due to osteoarthritis, traumatoid arthritis, polyarthritis, polyarthritis or osteonecrosis of the knee.

· Post traumatic loss of joint function.

· Moderate varus, valgus or flexion deformity.
· Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.

· Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

Type of Use (Select one or both, as applicable)
-------------------------------------------------	-------------

X Prescription Use (Part 21 CFR 801 Subpart D)

| | Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

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Section 5: 510(k) Summary

The following 510(k) Summary is provided as per 21 CFR 807.92 requirements

Subject Device: (Proprietary/Trade name):	iTotal Identity® Cruciate Retaining (CR) Knee Replacement SystemiTotal Identity® Posterior Stabilized (PS) Knee Replacement System
Common Usual Name:	Knee Replacement System
Type of Submission:	Special 510(k)
Device Class:	II
Regulation Number:	888.3560
Regulation Description:	Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Primary Product Classification(Product Code) and Description:	JWHKnee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Secondary Product Classifications(Product Code) and Descriptions:	OOG, OIYKnee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Reviewing Agency:	Orthopedics
Date of Summary Preparation:	November 19 2020
Submitter's Name and Address:	Conformis Inc.600 Technology Park DriveFourth FloorBillerica, MA 01821USA
Telephone Number:	(781) 345-9001
Establishment RegistrationNumber(s):	30098446033004153240
Contact Name:	Mary Kruitwagen
Contact Telephone:	781-345-9038
Contact email:	Mary.Kruitwagen@conformis.com
Alternate Contact:	Kara Johnson
Alternate Contact Telephone:	781-832-5402
Alternate Contact email:	Kara.Johnson@conformis.com
Primary Predicate Device:	iTotal Identity® Cruciate Retaining (CR) Knee Replacement System
Primary Predicate Device 510(k):	K190562; August 8, 2019
Primary Predicate Device ProductClassification (ProCode) andDescription:	JWH, OOG, OIYKnee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Secondary Predicate Device:	iTotal Identity® Posterior Stabilized (PS) Knee Replacement System
Secondary Predicate Device 510(k):	K201023; June 16, 2020
Secondary Predicate Device Classification (ProCode) and Description:	Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Modification	This submission is to seek clearance for use of an alternate chemically and physically equivalent Highly Cross-Linked Vitamin E Stabilized Ultra-High Molecular Weight polyethylene raw material (iPoly® XE) for the manufacture of the patellar component and the tibial inserts.
Device Description	iTotal Identity® Cruciate Retaining (CR) Knee Replacement System (KRS) and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System (KRS) are patient specific tri-compartmental faceted knee replacements systems. The iTotal Identity CR KRS is a faceted posterior cruciate ligament retaining knee replacement system. It is a semi-constrained, cemented knee implant which consists of femoral, tibial, and patellar components. iTotal Identity® PS KRS is a semi-constrained, cemented knee implant consisting of femoral, tibial, patellar and articular tibial insert components.Using patient imaging 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 and tray keel stem extension manufactured from titanium (Ti6AL4V-ELI) alloy, a tibial tray keel cap manufactured from polyethylene (UHMWPE) and either one or two polyethylene inserts (Two piece is CR only). The polyethylene inserts may be manufactured from either UHMWPE or iPoly® XE (a highly cross-linked vitamin E stabilized UHMWPE). The patellar component is provided in either a round or oval dome shape and may be manufactured from either UHMWPE or iPoly® XE.For user convenience, single-use, patient-specific ancillary orthopedic manual surgical instruments designed for use with the proposed iTotal Identity® CR KRS or iTotal Identity® PS KRS are provided to assist in the positioning of the total knee replacement components intraoperatively and in guiding the cutting of bone. In addition, reusable orthopedic manual surgical instruments are provided separately.
Indications for Use	iTotal Identity® Cruciate Retaining (CR) Knee Replacement SystemThe iTotal Identity® Cruciate Retaining (CR) Knee Replacement System (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, patellofemoral or bicompartmental prosthesis.

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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, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.
Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

iTotal Identity® Posterior Stabilized (PS) Knee Replacement System

The Indications for Use include:

Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid ● arthritis, polyarthritis or osteonecrosis of the knee.
Post traumatic loss of joint function.
Moderate varus, valgus or flexion deformity.
Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral or ● bicompartmental implants.
. Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.

This implant is intended for cemented use only.

Technological Characteristics

The proposed and predicate devices are cemented knee implants that consist of three primary components; femoral, tibial, and patellar implants. Single-use, patient-specific ancillary surgical instruments are provided for use to assist with surgical implantation. Reusable ancillary surgical instruments, provided in a reusable instrument tray, assist with surgical implantation.

The subject devices iTotal Identity Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System are the same as the predicate devices with regards to:

Indications for Use ●
Device design
Device usage
Operating principles
Packaging
Sterilization methods

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Biocompatibility
. Shelf-life
. Femoral implant material
Tibial tray Material

The modification is to add an alternate iPoly® XE raw material which is a physically and chemically equivalent Highly Cross-linked Vitamin E Stabilized UHMWPE XE to manufacture the

Patellar component
Tibial inserts

The manufacture of the subject device is otherwise unchanged from the predicate devices.

Performance Data Testing to compare the subject raw material to the predicate material was conducted. The difference between the subject raw material and the predicate raw material is that the subject raw material will not be mechanically annealed. The absence of an annealing step in the processing of the raw material does not have a statistically significant impact on the physical or chemical properties when compared to the predicate material and supports that the materials are equivalent.

In conclusion, the subject raw material raises no new issues regarding safety or effectiveness. The performance of the modified devices is expected to be the same as the currently marketed predicate devices.

Substantial The modification to add an additional iPoly® XE raw material applies to the Equivalence patellar component and the tibial inserts. The Assessment of physical and chemical characterization of the predicate and subject materials shows equivalency of the subject material to the predicate material. Results support that the performance of the subject devices would be the same as the predicate devices.

The subject devices, iTotal Identity® Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System, are substantially equivalent to the predicate devices iTotal Identity® Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System.

Conclusion Based on the intended use, technological characteristics, and outcome of the performance data the subject devices, iTotal Identity® Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System, are substantially equivalent to the predicate devices iTotal Identity® Cruciate Retaining (CR) Knee Replacement System and iTotal Identity® Posterior Stabilized (PS) Knee Replacement System.

Regulation Number and Section

§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

(a)
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).(b)
Classification. Class II.