Severely painful and/or disabled joint as a result of osteoarthritis, post-traumatic arthritis, inflammatory arthritis or hip dysplasia.
Avascular necrosis of the femoral head.
Acute fracture of the femoral head.
Acute fracture of the proximal femur, suitable to be treated by means of hip arthroplasty.
Non-union of proximal femur fracture, suitable to be treated by means of hip arthroplasty.
Primary pathology involving the femoral head but with a non-deformed acetabulum.
Failure of previous hip surgery:
- Conservative hip surgery.
- Internal fixation.
- Arthrodesis.
- Partial or total hip arthroplasty.
- Hip resurfacing replacement.

Device Description

The Mfinity Femoral System includes implantable devices provided individually packed, sterile and single-use intended for cementless use in total or partial hip arthroplasty to replace the native femoral neck for primary or revision surgery. The product range is composed of three different versions (Mfinity collarless, Mfinity collared and Mfinity L) available in standard and lateral offset.

The Mfinity femoral stem can be combined with the CoCr ball head (K072857, K080885 and K103721), Endo Head (K111145), the MectaCer BIOLOX® forte (K073337), MectaCer BIOLOX® Delta Femoral Heads (K112115) or MectaCer BIOLOX® Option Heads (K131518).

The subject devices are made of titanium alloy according to ISO 5832-11 and coated with Titanium plasma spray according to ASTM F1580 and Hydroxyapatite according with ASTM F1185.

AI/ML Overview

The provided text is an FDA 510(k) clearance letter for the Mfinity Femoral System, which is a hip prosthesis, not a diagnostic AI device. Therefore, the information requested regarding acceptance criteria and studies that prove a device meets those criteria, specifically concerning AI performance metrics, expert adjudication, training set, and test set details, is not applicable to this document.

The document discusses the substantial equivalence of the Mfinity Femoral System to predicate devices based on non-clinical performance data (fatigue tests, ROM evaluation, surface analyses, biocompatibility, shelf-life, pyrogenicity) and states that no clinical studies were conducted.

The acceptance criteria for this type of medical device (hip prosthesis) would typically involve demonstrating mechanical strength, durability, biocompatibility, and sterilization effectiveness based on recognized standards (e.g., ISO, ASTM, European Pharmacopoeia, USP). The "reported device performance" would consist of the results of these non-clinical tests meeting the specified limits of those standards.

Below is a general interpretation of what "acceptance criteria" and "reported device performance" would entail for a hip prosthesis based on the provided document, acknowledging that specific numerical details of these criteria and results are not explicitly stated in this letter but would be in the full 510(k) submission.

Based on the provided FDA 510(k) Clearance Letter for the Mfinity Femoral System:

This document describes the clearance of a hip prosthesis, not an AI-powered diagnostic device. Therefore, the typical elements of acceptance criteria and study designs relevant to AI (such as sensitivity, specificity, AUC, expert consensus, training/test set sizes, etc.) are not applicable to this submission.

The "acceptance criteria" for this device would generally refer to meeting established mechanical, material, and biological performance standards for medical implants. The "study that proves the device meets the acceptance criteria" refers to the non-clinical performance testing conducted.

Here's an attempt to populate the requested table and answer the questions based on the information available, while highlighting the irrelevance of AI-specific questions:

1. Table of Acceptance Criteria and the Reported Device Performance

Acceptance Criteria Category	Specific Criteria (General based on device type)	Reported Device Performance (Summary from letter)
Mechanical Performance	- Fatigue strength (ISO 7206-4, ISO 7206-6) - Pull-off strength of femoral head - Range of Motion (ISO 21535)	- Mfinity Fatigue tests performed according to ISO 7206-4 and ISO 7206-6 (Results are assumed to have met specified limits) - Pull-Off Test On CoCr Femoral Head performed (Results are assumed to have met specified limits) - Evaluation of ROM according to ISO 21535 performed (Results are assumed to have met specified limits)
Material Performance	- Coating characteristics (cross-section, SEM, XRD)	- Cross sectioned area evaluation of double coated implant surfaces performed - Scanning Electron Microscopy pictures of double coated implant surfaces taken - XRD analyses comparing HA coating on Mfinity stem and planar samples performed (Results are assumed to demonstrate acceptable coating properties)
Biocompatibility	- Material safety - Cytotoxicity, sensitization, irritation, genotoxicity, chronic toxicity, etc.	- Biocompatibility assessment performed (Results are assumed to demonstrate compliance with standards)
Sterilization & Endotoxin	- Bacterial endotoxin levels (European Pharmacopoeia §2.6.14 / USP <85>) - Pyrogenicity (USP <151>)	- Bacterial endotoxin test (LAL test) performed - Pyrogen test performed (Results are assumed to meet requirements, though note indicates not labeled as non-pyrogenic or pyrogen free)
Shelf-Life	- Maintain integrity and performance over specified shelf-life	- Shelf-life evaluation performed (Results are assumed to demonstrate acceptable shelf-life)

2. Sample size used for the test set and the data provenance

Sample Size for Test Set: Not specified in the FDA letter. For non-clinical tests (like fatigue or material analysis), sample sizes would be determined by the specific ISO/ASTM standards referenced, but these are not diagnostic "test sets" in the AI context.
Data Provenance: The data comes from the "Non-Clinical Studies" and "Performance Testing" conducted by Medacta International S.A. No country of origin is explicitly stated for the testing labs or data generation, but the company is based in Switzerland. The studies are by nature prospective in that they are conducted specifically to test the device's performance against standards.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not Applicable. This is a hip prosthesis, not an AI diagnostic device. There is no concept of "ground truth" established by experts in the context of interpreting images or medical conditions for this device. The "ground truth" for the performance tests would be the established scientific and engineering principles and the limits defined by the relevant ISO/ASTM standards.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not Applicable. As this is not an AI diagnostic device, no adjudication method was used. Performance is assessed directly against objective engineering and material standards.

5. 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

Not Applicable. This is a hip prosthesis, not an AI-assisted diagnostic tool. No MRMC study was performed, and there is no AI assistance involved. The letter explicitly states: "No clinical studies were conducted."

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not Applicable. This is not an algorithm or AI device. The device (a physical implant) is evaluated standalone based on its inherent properties and performance against physical and material standards.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The "ground truth" for the non-clinical performance tests is based on established engineering and material science standards and specifications (e.g., ISO 7206, ISO 21535, ASTM F1580, ASTM F1185, European Pharmacopoeia, USP). The device's performance is compared against the requirements and acceptance limits set forth in these standards.

8. The sample size for the training set

Not Applicable. This device did not involve machine learning or a "training set."

9. How the ground truth for the training set was established

Not Applicable. This device did not involve machine learning or a "training set."

Summary

FDA 510(k) Clearance Letter - Mfinity Femoral System

Page 1

June 13, 2025

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

Re: K251166
Trade/Device Name: Mfinity Femoral System
Regulation Number: 21 CFR 888.3353
Regulation Name: Hip Joint Metal/Ceramic/Polymer Semi-Constrained Cemented Or Nonporous Uncemented Prosthesis
Regulatory Class: Class II
Product Code: MEH, LZO, KWY, KWL, LPH
Dated: April 15, 2025
Received: April 15, 2025

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 (the 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 available 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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K251166 – Christopher Lussier Page 2

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 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-devices/medical-device-safety/medical-device-reporting-mdr-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/medical-devices/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-devices/device-advice-comprehensive-regulatory-

Page 3

K251166 – Christopher Lussier Page 3

assistance/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,

RYAN TROMBETTA -S

For: Limin Sun, Ph.D.
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

Page 4

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2023
See PRA Statement below.

510(k) Number (if known): K251166

Device Name: Mfinity Femoral System

Indications for Use (Describe)

Mfinity femoral stems are indicated in patients requiring hip arthroplasty.

Hip Arthroplasty

Total or partial hip arthroplasty is indicated in the following cases:

Severely painful and/or disabled joint as a result of osteoarthritis, post-traumatic arthritis, inflammatory arthritis or hip dysplasia.
Avascular necrosis of the femoral head.
Acute fracture of the femoral head.
Acute fracture of the proximal femur, suitable to be treated by means of hip arthroplasty.
Non-union of proximal femur fracture, suitable to be treated by means of hip arthroplasty.
Primary pathology involving the femoral head but with a non-deformed acetabulum.
Failure of previous hip surgery:
- Conservative hip surgery.
- Internal fixation.
- Arthrodesis.
- Partial or total hip arthroplasty.
- Hip resurfacing replacement.

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
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"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."

Page 5

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 and Regulatory, Medacta USA

Date Prepared: April 15, 2025
Date Revised: June 13, 2025

II. Device

Device Proprietary Name: Mfinity Femoral System
Common or Usual Name: Total Hip Prosthesis
Classification Name: Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis
Primary Product Code: MEH
Secondary Product Code: LZO, KWY, KWL, LPH
Regulation Number: 21 CFR 888.3353, 21 CFR 888.3390, 21 CFR 888.3360, 21 CFR 888.3358
Device Classification: II

III. Predicate Device

Substantial equivalence is claimed to the following predicate devices.

Primary Predicate device:

Actis DuoFix Hip Prosthesis- Collarless, K210581, DePuy Ireland UC

Additional Predicate devices:

DePuy Actis DuoFix Hip Prosthesis, K160907, DEPUY ORTHOPAEDICS, INC
DePuy Actis Duofox Hip Prosthesis, K150862, DEPUY ORTHOPAEDICS, INC
Quadra-P, K192827, Medacta International SA
Quadra-P, K181254, Medacta International SA
AMIStem-P, K173794, Medacta International SA

Reference devices:

Masterloc, K151531, Medacta International SA
GMK Sphere & GMK SpheriKA Cementless, K223548, Medacta International SA

K251166 Page 1 of 4

Page 6

IV. Device Description

The subject devices are made of titanium alloy according to ISO 5832-11 and coated with Titanium plasma spray according to ASTM F1580 and Hydroxyapatite according with ASTM F1185.

V. Indications for Use

Mfinity femoral stems are indicated in patients requiring hip arthroplasty.

Hip Arthroplasty

Total or partial hip arthroplasty is indicated in the following cases:

Severely painful and/or disabled joint as a result of osteoarthritis, post-traumatic arthritis, inflammatory arthritis or hip dysplasia.
Avascular necrosis of the femoral head.
Acute fracture of the femoral head.
Acute fracture of the proximal femur, suitable to be treated by means of hip arthroplasty.
Non-union of proximal femur fracture, suitable to be treated by means of hip arthroplasty.
Primary pathology involving the femoral head but with a non-deformed acetabulum.
Failure of previous hip surgery:
- Conservative hip surgery.
- Internal fixation.
- Arthrodesis.
- Partial or total hip arthroplasty.
- Hip resurfacing replacement.

VI. Comparison of Technological Characteristics

The subject and predicate devices (K150862, K160907, K210581) are substantially equivalent with respect to the following characteristics:

Range of product;
Taper;
Fixation;
Biocompatibility;
Device usage;
Packaging; and
Sterilization.

The subject devices differ from the predicate devices (K150862, K160907, K210581) with respect to:

CCD angle;
Stem length;
Neck offset; and

K251166 Page 2 of 4

Page 7

Materials.

Discussion

The different CCD angles between the subject and predicate devices (K150862, K160907, K210581) does not affect safety and effectiveness since the subject devices' CCD angles are shared with Medacta predicate devices (K192827, K181254).

The partially different stem lengths between the subject and predicate devices (K150862, K160907, K210581) do not introduce any new risk of safety and effectiveness since they are included in the stem lengths of Medacta predicate devices: AMIStem-P (K173794) for the smaller lengths and Quadra-P (K192827, K181254) for the longer lengths.

Slightly bigger neck offset of the subject Mfinity L does not arise any new issue with respect to safety and effectiveness as demonstrated by mechanical evaluations.

The different material of the subject and predicate devices does not introduce new questions of safety and effectiveness since both the substrate material and the Titanium coating of the subject devices are shared with the additional predicate device, Masterloc (K151531).

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.

VII. Performance Data

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

Non-Clinical Studies

DESIGN VALDATION
- Mfinity Design Validation
PERFORMANCE TESTING
- Mfinity Fatigue tests according to ISO 7206-4 and ISO 7206-6
- Pull-Off Test On CoCr Femoral Head
- Evaluation of ROM according to ISO 21535
- Cross sectioned area of the double coated implant surfaces of the Medacta Mfinity stem
- Scanning Electron Microscopy pictures of the double coated implant surfaces of the Mfinity stem
- XRD analyses comparing features of the HA coating deposed on the Medacta Mfinity stem and on planar samples made of Ti6Al7Nb
PYROGENICITY
- Bacterial endotoxin test (LAL test) according to European Pharmacopoeia §2.6.14 (which is equivalent to USP chapter <85>)
- Pyrogen test according to USP chapter <151> for pyrogenicity determination
- The subject devices are not labeled as non-pyrogenic or pyrogen free.

K251166 Page 3 of 4

Page 8

BIOCOMPATIBILITY assessment
SHELF-LIFE evaluation

Clinical Studies:

No clinical studies were conducted.

VIII. Conclusion

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

K251166 Page 4 of 4

Regulation Number and Section

§ 888.3353 Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.

(a)
Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.(b)
Classification. Class II.