Open and Closed Fractures
Post-traumatic joint contracture which has resulted in loss of range of motion
Fractures and disease which generally may result in joint contractures or motion and fractures requiring distraction
Pseudoarthrosis or non-union of long bones
Limb lengthening by epiphyseal or metaphyseal distraction
Correction of bony or soft tissue deformity
Correction of segmental bony or soft tissue defects
Joint arthrodesis
Management of comminuted intra-articular fractures of the distal radius

The Stryker Hoffmann LRF System is indicated in adults for:

Osteotomy
Revision procedure where other treatments or devices have been unsuccessful
Bone reconstruction procedures
Fusions and replantations of the foot
Charcot foot reconstruction
Lisfranc dislocations

Device Description

Originally cleared in K113327, the Hoffmann LRF System is an external fixation device that consists of carbon and aluminum full/open rings and ring segments, aluminum foot rings, threaded rods and threaded rod connecting nuts, telescopic struts, static struts and connection bolts, posts and connecting nuts, wires and wire bolt offset adapters, pin bolts and pin adapters, and washers.

Modifications to the previously cleared telescopic strut and wire bolt components, as part of the currently marketed Hoffmann LRF (Limb Reconstruction Frame) System in K113327, were cleared in K130334.

Additional components (carbon foot ring, foot arch, hinge coupling) were cleared in K130907 as a line extension to the currently marketed Hoffmann LRF (Limb Reconstruction Frame) System in K113327.

This Traditional 510(k) submission is being supplied to the U.S. FDA to provide authorization to market the inclusion of additional components to the previously cleared Hoffmann LRF (Limb Reconstruction Frame) System, in K130907. The additional components of this submission will consist of the following: constrained hinge strut, universal hinge strut, motor struts, spherical washer, hinge bolt, self-locking nut, half hinge, universal joint, adjustment instrument, slotted plate and buckle.

This external fixation system may also be used with the components of other Stryker Trauma AG external fixation systems such as the Monticelli Spinelli External Fixation System, the Hoffmann II, Hoffman II MRI and Hoffmann 3 External Fixation System, and the Apex Fixation Pins.

AI/ML Overview

The provided FDA 510(k) summary for the Hoffmann LRF (Limb Reconstruction Frame) System describes a medical device, not an AI/ML-driven diagnostic or prognostic tool. Therefore, the information requested about acceptance criteria for AI models, sample sizes for training/test sets, expert ground truth, MRMC studies, standalone performance, and data provenance is not applicable in this context.

This submission is for additional components to an existing external fixation device, and the evaluation relies on non-clinical laboratory testing to demonstrate substantial equivalence to predicate devices, rather than clinical performance data or AI model validation.

Here's the relevant information from the document as it pertains to the device's performance demonstration:

1. A table of acceptance criteria and the reported device performance

Acceptance Criteria (Implied by standard)	Reported Device Performance (Summary)
Compliance with ASTM F1541-02	Testing demonstrated substantial equivalence to the predicate device components.
Sufficient mechanical strength/durability for intended use (implied by specific tests)	Passed Static Cantilever Bending Test, Dynamic Cantilever Bending Test, Dynamic Frame Testing.

Note: The document states "Testing demonstrated that the Hoffmann LRF (Limb Reconstruction Frame) System added components are substantially equivalent to the predicate device components." The specific quantitative acceptance values (e.g., maximum deflection, fatigue life cycles) from ASTM F1541-02 and the precise performance metrics achieved are not detailed in this summary. The "acceptance criteria" here are implied by the standard itself and the need to show equivalence.

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Sample Size: The document does not specify the number of components or test units used for each non-clinical test (Static Cantilever Bending, Dynamic Cantilever Bending, Dynamic Frame Testing).
Data Provenance: This relates to non-clinical laboratory testing of mechanical properties, not patient data. It was performed by Stryker Trauma AG, headquartered in Switzerland, though the specific lab location is not stated. These are "prospective" engineering tests designed to evaluate the physical properties of the device components.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable. Ground truth, in the context of AI models, refers to expert-labeled data. For a physical medical device, "ground truth" for non-clinical testing is typically defined by engineering specifications, material properties, and established test standards (e.g., ASTM F1541-02). The "experts" would be the engineers and technicians conducting and analyzing the mechanical tests. Their qualifications are not specified but would be standard for mechanical engineering and materials testing.

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

Not applicable. Adjudication methods are used to resolve discrepancies in expert labeling for AI ground truth. For mechanical testing, if there were issues, they would typically involve repeated tests, calibration checks, or review by senior engineers. The document does not mention an adjudication method.

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 device is an external fixation system, not an AI-assisted diagnostic or prognostic tool. No human readers, cases, or AI assistance are involved in its performance evaluation as described here.

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 model. The "standalone" testing refers to the non-clinical mechanical tests where the device components were tested without human intervention impacting the mechanical properties being measured.

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

The "ground truth" for this device's performance in non-clinical testing is based on:

Engineering Specifications: The design parameters and material specifications of the device components.
Standardized Test Methods: Adherence to established industry standards like ASTM F1541-02, which provides defined procedures and expected performance envelopes for external skeletal fixation devices.
Predicate Device Performance: The mechanical performance of the legally marketed predicate devices, against which the new components are shown to be "substantially equivalent."

8. The sample size for the training set

Not applicable. There is no training set as this is not an AI/ML device.

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

Not applicable. There is no training set for an AI/ML device.

Summary

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Image /page/0/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular border with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized image of an eagle or bird with three overlapping profiles, creating a sense of depth and movement.

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

November 10, 2014

Stryker Trauma AG Ms. Nesli Karakaya Associate Regulatory Affairs Manager Bohnackerweg 1 CH-2545 Selzach Switzerland

Re: K140961 Trade/Device Name: Hoffmann LRF (Limb Reconstruction Frame) System Regulation Number: 21 CFR 888.3030 Regulation Name: Single/multiple component metallic bone fixation appliances and accessories Regulatory Class: Class II Product Code: KTT Dated: September 29, 2014 Received: October 8, 2014

Dear Ms. Karakaya:

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 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 803); good manufacturing practice requirements as set

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Page 2 – Ms. Nesli Karakaya

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 contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. 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 Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Lori A. Wiggins -S

for

Mark N. Melkerson Director Division of Orthopedic Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120 Expiration Date: January 31, 2017 See PRA Statement below.

510(k) Number (if known) K140961

Device Name

Hoffmann LRF (Limb Reconstruction Frame) System

Indications for Use (Describe)

The Stryker Hoffmann LRF (Limb Reconstruction Frame) System is indicated in pediatric patients and adults for the treatment and fixation of:

· Open and Closed Fractures
· Post-traumatic joint contracture which has resulted in loss of range of motion
· Fractures and disease which generally may result in joint contractures or motion and fractures requiring distraction
Pseudoarthrosis or non-union of long bones
· Limb lengthening by epiphyseal or metaphyseal distraction
· Correction of bony or soft tissue deformity
· Correction of segmental bony or soft tissue defects
· Joint arthrodesis
· Management of comminuted intra-articular fractures of the distal radius

The Stryker Hoffmann LRF System is indicated in adults for:

· Osteotomy
Revision procedure where other treatments or devices have been unsuccessful
Bone reconstruction procedures
· Fusions and replantations of the foot
· Charcot foot reconstruction
· Lisfranc dislocations

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

2 Prescription Use (Part 21 CFR 801 Subpart D)

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

PLEASE DO NOT WRITE BELOW THIS LINE -- CONTINUE ON A SEPARATE PAGE IF NEEDED.

FOR FDA USE ONLY

Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)

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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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510(k) Summary

Proprietary Name:	Hoffmann LRF (Limb Reconstruction Frame) System
Common Name:	External Fixation Device
Classification Name and Reference:	Single/multiple component metallic bone fixationappliances and accessories 21 CFR §888.3030
Regulatory Class:	Class II
Product Codes:	KTT-Appliance, fixation, nail/blade/plate combinationmultiple components
Sponsor:	Stryker Trauma AGBohnackerweg 1CH-2545 SelzachSwitzerland
Contact Information:	Nesli Karakaya, RACAssociate Regulatory Affairs ManagerBohnackerweg 1CH-2545 SelzachSwitzerlandPhone: +41 32 641 69 30 Fax: +41 32 641 66 60nesli.karakaya@stryker.com
Date Prepared:	April 10, 2014

Description:

Modifications to the previously cleared telescopic strut and wire bolt components, as part ● of the currently marketed Hoffmann LRF (Limb Reconstruction Frame) System in K113327, were cleared in K130334.
Additional components (carbon foot ring, foot arch, hinge coupling) were cleared in . K130907 as a line extension to the currently marketed Hoffmann LRF (Limb Reconstruction Frame) System in K113327.
This Traditional 510(k) submission is being supplied to the U.S. FDA to provide ● authorization to market the inclusion of additional components to the previously cleared Hoffmann LRF (Limb Reconstruction Frame) System, in K130907. The additional components of this submission will consist of the following: constrained hinge strut,

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universal hinge strut, motor struts, spherical washer, hinge bolt, self-locking nut, half hinge, universal joint, adjustment instrument, slotted plate and buckle.

Intended Use:

The Hoffmann LRF (Limb Reconstruction Frame) System is intended for fixation of fractures, joint contractures, fusions, limb lengthening, deformity correction, bone and soft tissue reconstruction in pediatric patients and adults.

Indications:

The Stryker Hoffmann LRF (Limb Reconstruction Frame) System is indicated in pediatric patients and adults for the treatment and fixation of:

Open and Closed Fractures ●
Post-traumatic joint contracture which has resulted in loss of range of motion ●
Fractures and disease which generally may result in joint contractures or loss of range ● of motion and fractures requiring distraction
Pseudoarthrosis or non-union of long bones
. Limb lengthening by epiphyseal or metaphyseal distraction
Correction of bony or soft tissue deformity ●
Correction of segmental bony or soft tissue defects .
Joint arthrodesis
Management of comminuted intra-articular fractures of the distal radius

The Stryker Hoffmann LRF System is indicated in adults for:

Osteotomy .
Revision procedure where other treatments or devices have been unsuccessful ●
Bone reconstruction procedures .
Fusions and replantations of the foot ●
Charcot foot reconstruction ●
Lisfranc dislocations

Summary of Technologies:

Device comparison showed that the proposed device is substantially equivalent in intended use, materials and performance characteristics to the following predicate devices:

. Hoffmann LRF (Limb Reconstruction Frame) System- K113327/ K130334/ K130907
. External Fixation System (Smith and Nephew)- K031181

Non-Clinical Testing:

Non-clinical laboratory testing was performed for the Hoffmann LRF (Limb Reconstruction Frame) System on the additional components and component compatibility. Testing was

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performed with compliance to ASTM F1541-02 - "Standard Specification and Test Methods for External Skeletal Fixation Device." Testing demonstrated that the Hoffmann LRF (Limb Reconstruction Frame) System added components are substantially equivalent to the predicate device components. Testing included the following:

Static Cantilever Bending Test ●
Dynamic Cantilever Bending Test
. Dynamic Frame Testing

Clinical Testing: Clinical testing was not required for this submission.

Conclusion: The Hoffmann LRF (Limb Reconstruction Frame) System is substantially equivalent to the predicate devices identified in this premarket notification.

Regulation Number and Section

§ 888.3030 Single/multiple component metallic bone fixation appliances and accessories.

(a)
Identification. Single/multiple component metallic bone fixation appliances and accessories are devices intended to be implanted consisting of one or more metallic components and their metallic fasteners. The devices contain a plate, a nail/plate combination, or a blade/plate combination that are made of alloys, such as cobalt-chromium-molybdenum, stainless steel, and titanium, that are intended to be held in position with fasteners, such as screws and nails, or bolts, nuts, and washers. These devices are used for fixation of fractures of the proximal or distal end of long bones, such as intracapsular, intertrochanteric, intercervical, supracondylar, or condylar fractures of the femur; for fusion of a joint; or for surgical procedures that involve cutting a bone. The devices may be implanted or attached through the skin so that a pulling force (traction) may be applied to the skeletal system.(b)
Classification. Class II.