The MyKnee UNI-ST blocks are based on CT or MRI scans of the knee and they are intended for use as anatomical cutting blocks or pin positioners specifically designed for each patient to assist in the intraoperative positioning of the tibial unicompartmental component and to guide the marking of the bone before cutting.

The MyKnee UNI-ST blocks are intended for use with MOTO Partial Knee systems when the clinical evaluation complies with clear indications for use. MyKnee UNI-ST blocks are intended for single use only.

Device Description

MyKnee UNI-ST are a line extension to the currently marketed MyKnee Cutting Blocks (K093806), MyKnee PPS-Pin Positioners (K170106) and MyKnee R Pin Positioners (K220705).

The MyKnee UNI-ST are single use, patient-specific tibial cutting blocks which allows the surgeon to carry out the tibial resection according to the preoperative 3D plan based on CT or MRI images of the patient's knee.

The MyKnee UNI-ST cutting blocks are available in left and right medial configuration with a range of sizes covering the whole MOTO tibial implant portfolio for which they are intended for use with.

Identically to the predicate devices, the MyKnee UNI-ST are manufactured from medical grade nylon for sintering and they can be provided in both non-sterile and sterile version.

AI/ML Overview

This is a 510(k) premarket notification for a medical device called "MyKnee UNI-ST," which are patient-specific tibial cutting blocks used in knee replacement surgery. The submission claims substantial equivalence to a legally marketed predicate device.

The provided text does not contain acceptance criteria or a study that rigorously proves the device meets specific performance criteria in terms of accuracy or clinical outcomes. Instead, it focuses on demonstrating substantial equivalence to a predicate device through non-clinical testing and leveraging existing data.

Here's an analysis based on the information provided, highlighting the absence of some requested details:

Table of acceptance criteria and the reported device performance:

Acceptance Criteria: Not explicitly stated as quantifiable metrics. The "performance data" section describes the types of tests performed rather than specific pass/fail criteria with numerical thresholds.
Reported Device Performance: The document only states that "performance testing was conducted to written protocols" and that "the comparison of technological characteristics and performance data provided within the submission supports the substantial equivalence of the subject devices respect to the predicate devices." No specific numerical results (e.g., accuracy in mm or degrees) from these tests are provided in this summary.

Acceptance Criterion (Implied/General)	Reported Device Performance (Summary)
Functionality for intended use	Verified in sawbone workshop.
Mechanical Resistance	Dimensional analysis showed no new worst-case compared to predicate.
Accuracy of placement & resection	Validated in cadaver testing.
Biocompatibility	Leveraged data from predicate devices.
Shelf-life	Leveraged data from predicate devices.
Sterilization	Leveraged data from predicate devices.

Sample size used for the test set and the data provenance:
- Sawbone workshop: Sample size not specified.
- Dimensional analysis: Sample size not specified.
- Cadaver testing: Sample size not specified.
- Data provenance: Not specified (e.g., country of origin). The testing seems to be internal ("conducted to written protocols"). It is not explicitly stated if it was retrospective or prospective, though cadaver and sawbone testing are typically prospective experiments.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not specified. The document does not describe a process for establishing ground truth by external experts for the performance tests mentioned (sawbone, dimensional analysis, cadaver). The validation was likely performed by internal R&D or clinical engineers.
Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable/Not specified. This typically applies to studies involving human interpretation or clinical endpoints adjudicated by experts. The performance tests described (sawbone, dimensional analysis, cadaver) are objective measurements without an adjudication process for consensus on observed outcomes.
If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No. This device is a physical cutting block for surgery, not an AI-assisted diagnostic or interpretive tool. Therefore, an MRMC study is not relevant or mentioned.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is a physical device, and its function involves direct interaction with a surgeon (human-in-the-loop for its application). The "accuracy of placement & resection" validated in cadaver testing is a form of performance evaluation for the device itself, but it's not an "algorithm-only" performance in the AI sense.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the sawbone and cadaver testing, the "ground truth" would likely be derived from objective measurements taken post-procedure against the pre-operative plan generated by the MyKnee system (which the cutting blocks implement). This involves comparing the actual bone cut/pin placement to the planned bone cut/pin placement, using precise measurement tools. It's an engineering ground truth based on design specifications and pre-operative planning, rather than a clinical ground truth like pathology or patient outcomes.
The sample size for the training set:
- Not applicable. This device is a patient-specific physical cutting block. It does not use machine learning or AI that requires a "training set" in the computational sense. Each block is custom-designed based on an individual patient's CT or MRI scan.
How the ground truth for the training set was established:
- Not applicable, as there is no "training set" for an AI or machine learning model. The "ground truth" for the design of each individual MyKnee UNI-ST block is the patient's anatomical data from their CT or MRI scan, which is used to generate the 3D model for the custom block.

Summary

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June 9, 2023

Medacta International S.A. % Christopher Lussier Senior Director, Quality, Regulatory and Clinical Research Medacta USA 6386 Global Drive, Suite 101 Memphis, Tennessee 38141

Re: K231037

Trade/Device Name: MyKnee UNI-ST Regulation Number: 21 CFR 888.3560 Regulation Name: Knee Joint Patellofemorotibial Polymer Semi-Constrained Cemented Prosthesis Regulatory Class: Class II Product Code: JWH Dated: April 11, 2023 Received: April 12, 2023

Dear Christopher Lussier:

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.

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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); 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 (QS) 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 medical devices and radiation-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.

Peter G.	Digitally signed by Peter G. Allen -S
Allen -S	Date: 2023.06.0915:09:46 -04'00'

FOR: Lixin Liu 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

Submission Number (if known)

K231037

Device Name

MyKnee UNI-ST

Indications for Use (Describe)

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)

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510(k) Summary

I. Submitter

Medacta International SA Strada Regina 6874 Castel San Pietro (CH) Switzerland Phone (+41) 91 696 60 60 Fax (+41) 91 696 60 66

Contact Person: Stefano Baj, Regulatory and Compliance Director, Medacta International SA Applicant Correspondent: Chris Lussier, Senior Director, Quality, Regulatory, and Clinical Research, Medacta USA

Date Prepared: April 11, 2023

II. Device

Device Proprietary Name:	MyKnee UNI-ST
Common or Usual Name:	Prosthesis, Knee, Patellofemorotibial, Semi-Constrained, Cemented, Polymer/Metal/Polymer
Classification Name:	Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis
Primary Product Code	JWH
Regulation Number:	21 CFR 888.3560
Device Classification	II

III. Predicate Device

Substantial equivalence is claimed to the following primary predicate device:

A MyKnee Cutting Blocks, K093806, Medacta International SA.
Additionally, the following reference device is used within the submission:
A MyKnee R Pin Positioners, K220705, Medacta International SA.

IV. Device Description

MyKnee UNI-ST are a line extension to the currently marketed MyKnee Cutting Blocks (K093806), MyKnee PPS-Pin Positioners (K170106) and MyKnee R Pin Positioners (K220705).

The MyKnee UNI-ST cutting blocks are available in left and right medial configuration with a range of sizes covering the whole MOTO tibial implant portfolio for which they are intended for use with.

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Identically to the predicate devices, the MyKnee UNI-ST are manufactured from medical grade nylon for sintering and they can be provided in both non-sterile and sterile version.

V. Indications for Use

VI. Comparison of Technological Characteristics

The subject MyKnee UNI-ST cutting blocks are substantially equivalent to the predicate device, MyKnee cutting blocks (K093806), with regards to the following characteristics:

Checking features:
Applicable images file:
Manufacturing process:
Material:
. Biocompatibility:
Device usage:
Shelf-life: and
. Packaging.

The subject MyKnee UNI-ST cutting blocks differs respect to the predicate, MyKnee cutting blocks (K093806), with regards to the following characteristics:

Sizes:
. Anchoring points; and
Instruments compatibility. ●

Discussion

The technological differences between the subject and predicate devices do not raise new questions of safety and effectiveness.

Medacta International SA has not made any change to the manufacturing process, material, device usage, biocompatibility, sterility, shelf life, and packaging of the subject devices with respect to the predicate devices.

The comparison of technological characteristics and performance data provided within the submission supports the substantial equivalence of the subject devices respect to the predicate devices.

Performance Data VII.

Based on the risk analysis, performance testing was conducted to written protocols. The following validations are provided in support of the substantial equivalence determination:

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Non-Clinical Studies

Design validation
- Sawbone workshop verifying the functionality of the subject devices for their intended O use:
- Dimensional analysis to demonstrate that the subject devices do no not introduce a new o worst case with respect to mechanical resistance; and
- Cadaver testing validating the accuracy of the subject devices' placement on the bone and o the accuracy of the resection performed.
Biocompatibility data, shelf-life and sterilization studies submitted in support of the . predicate devices were leveraged.

Clinical Studies:

No clinical studies were conducted.

Conclusion VIII.

The information provided above supports that the subject devices are substantially equivalent to the predicate devices.

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.