Formus Hip is a preoperative surgical planning software. It is intended to assist qualified medical professionals in the preoperative planning of orthopedic surgical procedures.

Device Description

Formus Hip is a semi-automated Software as a Medical Device (SaMD) that allows pre-operative planning of primary total hip arthroplasty in real time using the Zimmer Biomet Taperloc G7 system. Using a series of algorithms, the software creates a 3D model and relevant measurements derived from the patient's pre-dimensioned CT scan. Formus Hip generates a 3D model without any user input. Additional algorithms fit the femoral stem and acetabular cup based on the patient anatomy. The software allows the user to adjust the plan interactively to achieve the desired clinical targets.

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the Formus Hip device, as extracted from the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

Endpoint	Acceptance Criteria	Reported Device Performance
Image Processing Accuracy (3D models from image segmentation)
Average Dice score	≥ 0.9	Hemipelvis: 0.95Femur: 0.97
Average Mean Absolute Distance (MAD)	≤ 2 mm	Hemipelvis: 1.15Femur: 1.35
Average Hausdorff Distance (HD) in femoral head and acetabulum	≤ 5 mm	Femoral head: 2.84Acetabulum: 3.04
Image Processing Accuracy (3D models of the proximal shaft inner cortical surface)
Average MAD	≤ 2 mm	Inner cortical surface: 1.02
Average HD	≤ 5 mm	Inner cortical surface: 2.80
3D models generated from statistical shape modeling
Average Dice score	≥ 0.9	Hemipelvis: 0.95Femur: 0.97
Average MAD	≤ 2 mm	Hemipelvis: 1.25Femur: 1.49
Average HD in femoral head and acetabulum	≤ 5 mm	Femoral head: 2.47Acetabulum: 2.93
Implant Sizing
Proportion of implant sizes (cup and stem) within ±2 sizes of ground truth	≥ 80%	Cup: 98% (95% CI 0.885 - 0.974)Stem: 94% (95% CI 0.947 - 0.998)

2. Sample Sizes and Data Provenance

Image Processing Accuracy (Test Set):

Sample Size: 60 images (from 60 patients)
Data Provenance: Acquired in the US (retrospective, implied by "images acquired... to validate accuracy")

Implant Sizing (Test Set):

Sample Size: 133 images (from 133 patients)
Data Provenance: Implied to be retrospective, acquired via a variety of common clinical CT scanners. Country of origin for this specific dataset is not explicitly stated but is implicitly within the context of demonstrating generalizability for the US patient population.

3. Number and Qualifications of Experts for Ground Truth (Test Set)

Image Processing Accuracy:

Number of Experts: 3 radiologists (2 segmenters, 1 senior reviewer)
Qualifications: US-board registered radiologists experienced in 3D image segmentation.

Implant Sizing:

Number of Experts: Orthopaedic surgeons (specific number not given, but implied to be multiple).
Qualifications: Orthopaedic surgeons.

4. Adjudication Method for the Test Set

Image Processing Accuracy:

Method: 2+1 adjudication. Each bone surface was manually segmented by two radiologists. A third senior radiologist reviewed each pair of segmentations and selected the most accurate segmentation as the final manually segmented mesh (ground truth).

Implant Sizing:

Method: Not explicitly described as an adjudication process between multiple experts. Ground truth was obtained by orthopaedic surgeons using traditional templating methods. This implies a single expert's determination per case or a consensus if multiple were involved, but the mechanism for resolving discrepancies isn't detailed.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a MRMC comparative effectiveness study was not reported. The studies described focus on the standalone algorithm's performance against expert-derived ground truth.

6. Standalone Performance Study

Yes, a standalone (algorithm only without human-in-the-loop performance) was performed.
- The "Image Processing Accuracy" study compared automatically generated 3D models from Formus Hip to manually segmented 3D models (ground truth).
- The "Implant Sizing" study compared implant sizes recommended by Formus Hip to "ground truth" implant sizes determined by orthopaedic surgeons using traditional templating methods.

7. Type of Ground Truth Used

Image Processing Accuracy:

Type: Expert consensus (adjudicated manual segmentation by radiologists).

Implant Sizing:

Type: Expert determination (implant sizes determined by orthopaedic surgeons using traditional templating methods).

8. Sample Size for the Training Set

Image Segmentation Algorithm: CT scans of male and female subjects with typical and atypical bony anatomy between the ages of 21 and 94. The exact number is not provided, only the demographics.
Statistical Shape Models: Segmented 3D models of male and female subjects with typical and atypical bony anatomy between the ages of 18 and 89. The exact number is not provided, only the demographics.

9. How the Ground Truth for the Training Set Was Established

The document states that the AI-based automatic image segmentation algorithm was "trained on CT scans" and statistical shape models were "trained on segmented 3D models". However, the specific process for establishing the ground truth (e.g., manual segmentation by experts, pathology confirmation, etc.) for these training datasets is not explicitly detailed in the provided text. It only mentions that training datasets are independent from testing and validation datasets and tracked in a single record file.

Summary

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March 31, 2023

Image /page/0/Picture/1 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA logo on the right. The FDA logo includes the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG" and "ADMINISTRATION" in blue text.

Formus Labs, Ltd % Richie Christian Head of Regulatory and Quality Suite 5, Floor 3, 30 St Benedicts Street Eden Terrace AUCKLAND 1010 NEW ZEALAND

Re: K213272

Trade/Device Name: Formus Hip Regulation Number: 21 CFR 892.2050 Regulation Name: Medical Image Management And Processing System Regulatory Class: Class II Product Code: QIH Dated: February 23, 2023 Received: February 23, 2023

Dear Richie Christian:

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 requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part

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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,

Amir Khan

For

Jessica Lamb, Ph.D. Assistant Director Imaging Software Team DHT8B: Division of Radiological Imaging Devices and Electronic Products OHT8: Office of Radiological Health 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) K213272

Device Name Formus Hip

Indications for Use (Describe)

Formus Hip is a pre-operative planning software for orthopedic surgery. The standalone software application imports patient diagnostic imaging studies (e.g. pre-dimensioned CT scans) from PACS-systems or other conventional medias. The Formus Hip system contains an integrated database of orthopedic hip implant geometries that can be overlayed to assist surgeons in their planning of orthopedic hip surgeries. The software application further enables the healthcare professional to customize their preoperative planning by means of an interactive graphical user interface. Finalized plans can be printed to a PDF report. The qualified healthcare professional can digitally perform the surgical planning and also make it available as a printable report. Clinical judgment and experience with the software are required for its successful use.

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)

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Image /page/3/Picture/0 description: The image contains the logo for Formus. The logo consists of a stylized spine graphic on the left and the word "formus" in blue font on the right. The spine graphic is made up of a series of dots connected by a curved line.

SUBMITTER 1.

Formus Labs Ltd. Suite 5, Floor 3, 30 St Benedicts Street Eden Terrace Auckland 1010 New Zealand

Contact Person:	Richie Christian, Head of Regulatory and Quality
Email:	richie@formuslabs.com

Last Updated: 31 March 2023

1. DEVICE

Name of Device:	Formus Hip
Classification Name:	Medical image management and processing system
Common Name:	Orthopedic Pre-operative Planning Software
Regulation:	21 CFR §892.2050
Regulatory Class:	II
Product Code:	QIH

3. PREDICATE DEVICE

PeekMed (K182464) This predicate has not been subject to a design-related recall.

DEVICE DESCRIPTION 4.

Formus Hip uses an Al-based automatic image segmentation algorithm trained on CT scans of male and female subjects with typical and atypical bony anatomy between the ages of 21 and 94. Formus Hip also uses statistical shape models of the femur and pelvis trained on segmented 3D models of male and female subjects with typical and atypical bony anatomy between the ages of 18 and 89.

The training datasets are independent from testing and validation datasets. Training data and internal testing data are tracked in a single record file under version control where they are labelled as either training or testing. Code used for training and testing is read from this record file so that a data point is never mixed between the training and testing datasets. Validation data was sourced from different geographies and stored in locations separate from training and internal testing data to ensure independence.

INTENDED USE 5.

Formus Hip is a preoperative surgical planning software. It is intended to assist qualified medical professionals in the preoperative planning of orthopedic surgical procedures.

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Image /page/4/Picture/0 description: The image shows the logo for Formus. The logo consists of a stylized spine on the left and the word "formus" in blue on the right. The spine is made up of a series of dots that are connected by a curved line.

INDICATIONS FOR USE 6.

Formus Hip is a pre-operative planning software for orthopedic surgery. The standalone software application imports patient diagnostic imaging studies (e.g. pre-dimensioned CT scans) from PACSsystems or other conventional medias. The Formus Hip system contains an integrated database of orthopedic hip implant geometries that can be overlayed to assist surgeons in their planning of orthopedic hip surgeries. The software application further enables the healthcare professional to customize their preoperative planning by means of an interactive graphical user interface. Finalized plans can be printed to a PDF report. The qualified healthcare professional can digitally perform the surgical planning and also make it available as a printable report. Clinical judgment and experience with the software are required for its successful use.

7. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE

The table below provides a comparison of the technological characteristics of Formus Hip and the legally marketed predicate device (PeekMed, K182464).

Device	Subject Device	Predicate Device
	Formus Hip	PeekMed
	(K213272)	K182464
Manufacturer	Formus Labs Ltd.	Peek Health, S.A.
Product Code	QIH	LLZ
Regulation Number	21 CFR 892.2050	21 CFR 892.2050
Regulation Name	System, Image	System, Image
	Processing, Radiological	Processing, Radiological
Intended Use	Formus Hip is a preoperative surgical	PeekMed is a preoperative
	planning software. It is	planning software for surgery
	intended to assist qualified medical
	professionals in the preoperative
	planning of orthopedic surgical
	procedures.
Indications for Use	Formus Hip is a pre-operative planning	PeekMed is a software system
	software for orthopedic surgery. The	designed to help surgeons'
	standalone software application imports	specialists carry out the preoperative
	patient diagnostic imaging studies (e.g.	planning in a prompt and efficient
	pre-dimensioned CT scans) from	manner for several surgical
	PACS-systems or other conventional	procedures, based on their patients'
	medias. The Formus Hip system	imaging studies. The software imports
	contains an integrated database of	diagnostics imaging studies such as x-
	orthopedic hip implant geometries that	rays, CT or magnetic resonance image
	can be overlayed to assist surgeons in	(MRI). The import process can retrieve
	their planning of orthopedic hip	files from a CD ROM, a local folder or
	surgeries. The software application	the PACS. In parallel, there is a
	further enables the healthcare	database of digital representations
	professional to customize their	related to prosthetic materials supplied
	preoperative planning by means of an	by their producing companies.
	interactive graphical user interface.	PeekMed allows health professional to
	Finalized plans can be printed to a PDF	digitally perform the surgical planning
	report. The qualified healthcare	without adding any additional steps to
	professional can digitally perform the	that process. This software system
	surgical planning and also make it	requires no imaging study acquisition
	available as a printable report. Clinical	specification (no protocol). Experience
	judgment and experience with the	in usage and a clinical assessment are
	software are required for its successful	necessary for a proper use of the
	use.	software.
Device	Subject DeviceFormus Hip(K213272)	Predicate DevicePeekMedK182464
Patient Population	Adults (≥ 21 years)	Adults and pediatrics
End Users	Qualified medical professionals	Surgeons
Computer	Personal computer or workstation	Personal computer or workstation
Operating System	Windows with a Chrome browser	Windows or OS X
Radiological ImageFormat	DICOM	DICOM
Device Availability	Can be accessed from the Chromeinternet browser launched from astandalone PC or workstation withinternet access.	It can be set to start from a workstationor standalone for planning procedure
Image Source	Receive digital images from varioussources (including PACS system)	Receive digital images from varioussources (including PACS system)
Data Processing	The software processes pre-dimensioned CT imaging to producedigital representations of the patientanatomy to which digitalrepresentations of prostheticcomponents are overlapped.	The software processes data inorder to provide an overlap anddimensioning of digital representationof the prosthetic material
Digital Overlap ofProsthetic Material	Allows the overlap of the digitalrepresentation of prostheticcomponents	Allows the overlap of models and theintersection of the models
Interactive ModelPositioning	Yes	Yes
Interactive ModelDimensioning	Yes	Yes
Model Rotation	Yes	Yes
Support for DigitalProsthetic materialsProvided by theManufacturers	Yes	Yes
AnatomicalLandmarks	Yes	Yes
MedicalSubspecialities	Hip	Hip, Knee, Spine, Upper Limb, Foot-and-Ankle, Trauma
Pre-specifiedProcedures	Total Hip Arthroplasty	Total Hip Arthroplasty(Additional joint replacements andassociated procedures specific toproduct intended for expandedindications)
Pre-surgicalPlanning	Yes	Yes
Contact with thePatient	No	No
Control of LifeSupporting Devices	No	No
Human Interventionfor ImageInterpretation	Yes	Yes
Ability to AddAdditional Modules	Yes	Yes

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Image /page/5/Picture/0 description: The image shows the logo for Formus. The logo consists of a stylized spine graphic on the left and the word "formus" in blue on the right. The spine graphic is made up of a series of black circles connected by a blue line. The word "formus" is written in a sans-serif font.

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Image /page/6/Picture/0 description: The image shows the logo for Formus. The logo consists of a stylized spine on the left and the word "formus" in blue on the right. The spine is made up of a series of circles connected by a curved line.

NON-CLINICAL PERFORMANCE DATA 8.

Software verification and validation was performed per Formus Labs' design and development processes which confirmed that the product specifications have been met. Formus Hip is classified as a "moderate" level of concern since a failure or latent flaw could indirectly result in minor injury to the patient.

Dedicated system verification testing including but not limited to automated tests and regression tests has been performed against pre-defined acceptance criteria. Each test met its predefined acceptance criteria for all functions of the software.

Dedicated validation has been performed on image processing accuracy and implant sizing, as below.

Image Processing Accuracy

Dedicated validation has been performed on 60 images acquired (from 60 patients) in the US to validate accuracy of image processing by comparing automatically generated 3D models of the femur and hemipelvis to the 3D models generated via manual segmentation by a panel of US radiologists. The images were acquired on Philips - Brilliance Big Bore, LightSpeed VCT using Formus Labs' standard CT protocol. The demographic distribution of this dataset is provided below.

. Gender: Male: 34; Female: 26
Minimum: 41; Maximum: 88 Age:
. Ethnicity: Black or African American: 18; Hispanic: 16; White: 16; Not specified: 10

Ground truth was obtained by US-board registered radiologists (truthers) experienced in 3D image segmentation. Each bone surface was manually segmented by two radiologists. A third senior radiologist reviewed each pair of segmentation and selected the most accurate segmentation which was the final manually segmented mesh.

Difference between the automatic (Formus Hip generated) and manual 3D models were quantified using the Sorensen-Dice coefficient (Dice), Mean Absolute Distance (MAD) and Hausdorff Distance (HD). All acceptance criteria were met, as shown in the table below.

Endpoint	Acceptance Criteria	Results
3D models from image segmentation	The average Dice score must be equal or greater than 0.9	Hemipelvis: 0.95Femur: 0.97
	The average MAD must be equal or less than 2 mm	Hemipelvis: 1.15Femur: 1.35
	The average HD must be equal or less than 5 mm in the femoral head and acetabulum	Femoral head: 2.84Acetabulum: 3.04
3D models of the proximal shaft inner cortical surface	The average MAD must be equal or less than 2 mm	Inner cortical surface: 1.02
	The average HD must be equal or less than 5 mm	Inner cortical surface: 2.80
3D models generated from statistical shape modelling	The average Dice score must be equal or greater than 0.9	Hemipelvis: 0.95Femur: 0.97
	The average MAD must be equal or less than 2 mm	Hemipelvis: 1.25Femur: 1.49
	The average HD must be equal or less than 5 mm in the femoral head and acetabulum	Femoral head: 2.47Acetabulum: 2.93

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Image /page/7/Picture/0 description: The image shows the logo for Formus. The logo consists of a stylized spine on the left and the word "formus" in blue on the right. The spine is made up of a series of black dots connected by a blue line, and the word "formus" is written in a sans-serif font.

Consistency in performance across all subgroups (i.e., sex, age, body mass index, ethnicity, and CT scanner) was assessed to demonstrate generalisability of the device across the intended US patient population.

Implant Sizing

A validation on implant sizing was performed on 133 images (from 133 patients) in which the implant sizes recommended by Formus Hip were compared to the implant sizes (ground truth) determined by orthopaedic surgeons. The images were acquired via a variety of common clinical CT scanners using Formus Labs' standard CT protocol. The demographic distribution of this dataset is provided below.

Male: 70; Female: 63 ● Gender:
. Minimum: 42; Maximum: 87 Age:

Ground truth was obtained by orthopaedic surgeons (truthers) using traditional templating methods. The different in sizes recommended by Formus Hip was compared with ground truth. The performance goal was that at least 80% of cup and stem sizes recommended by Formus Hip were within ±2 sizes of the around truth.

The acceptance criteria were met as the proportion of stems and cups recommended by Formus Hip that were within 2 sizes of ground truth were 94% (95% Cl 0.947 - 0.998) and 98% (95% Cl 0.885 - 0.974), respectively.

CLINICAL PERFORMANCE DATA 9.

Substantial equivalence was not based on an assessment of clinical performance data.

10. CONCLUSIONS

Formus Hip has the same intended use, indications for use, technological characteristics and principles of operation compared to the predicate device and does not raise different questions of safety or effectiveness.

Regulation Number and Section

§ 892.2050 Medical image management and processing system.

(a)
Identification. A medical image management and processing system is a device that provides one or more capabilities relating to the review and digital processing of medical images for the purposes of interpretation by a trained practitioner of disease detection, diagnosis, or patient management. The software components may provide advanced or complex image processing functions for image manipulation, enhancement, or quantification that are intended for use in the interpretation and analysis of medical images. Advanced image manipulation functions may include image segmentation, multimodality image registration, or 3D visualization. Complex quantitative functions may include semi-automated measurements or time-series measurements.(b)
Classification. Class II (special controls; voluntary standards—Digital Imaging and Communications in Medicine (DICOM) Std., Joint Photographic Experts Group (JPEG) Std., Society of Motion Picture and Television Engineers (SMPTE) Test Pattern).