(88 days)
Knee3 is intended to be an intraoperative localization system used during orthopedic knee surgery. It links a navigated instrument, tracked by a passive marker sensor system, to virtual computer image space on an individually acquired model of the patient's anatomical axes, which are generated through acquiring multiple anatomical bony landmarks. The system is indicated for medical conditions in which the use of stereotaxic surgery may be appropriate and where a reference to a rigid anatomical structure, such as the femur and tibia, can be identified relative to the acquired anatomical landmarks. The system aids the surgeon to plan resections, measure cutting block alignment, measure bone resections, and/or leg alignment. The device is indicated for total and uni-compartmental knee replacement.
The Knee3 is a software application module intended to be used on compatible navigation platforms that assist in the implantation of prosthetic knee implants. It uses instruments and accessories such as reference arrays, pointers and plane tools, which are tracked by an infrared camera of the respective platform, to determine femur and tibia anatomical landmarks as well as instrument positions in relation to the registered bones. The resulting navigation measurements support the user with the placement of the cutting guides.
The provided document, a 510(k) summary for Brainlab's Knee3 device, outlines the device's intended use, technological characteristics, and performance data to support its substantial equivalence to predicate devices. However, it does not present a formal table of acceptance criteria and reported device performance as typically seen in a clinical study report. Instead, it describes general accuracy limits for the system's technical navigation and mentions clinical validation through literature review.
Based on the provided text, here's what can be extracted and inferred regarding the device's acceptance criteria and the study proving it meets them:
1. A table of acceptance criteria and the reported device performance
The document does not provide a formal table with acceptance criteria side-by-side with reported performance for clinical validation. It offers a general statement about the system's technical accuracy:
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Technical navigation accuracy within ± 2° for angles and ± 2mm for distances in 95% of cases | Shown to be within limits of ± 2° for angles and ± 2mm for distances in 95% of cases. |
It's important to note that this is described as "technical navigation accuracy (bench accuracy)" and not a clinical accuracy directly on patients.
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
The document does not specify a sample size for a test set in the context of a prospective clinical study involving the Knee3 device itself. It states: "Clinical data gathered from literature was used to validate the accuracy of the predecessor software device versions (predicate devices) and respective workflows." This indicates a retrospective review of existing literature rather than a new prospective study with a dedicated test set for the Knee3.
Therefore, the data provenance is from literature regarding predicate devices, not specifically from a new study on Knee3. The country of origin of this literature data is not specified.
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)
Since the clinical validation was based on "clinical data gathered from literature" related to predicate devices, the document does not provide information on the number or qualifications of experts used to establish ground truth for this validation. This likely refers to the aggregated data and conclusions from various studies in the literature, not a specific panel of experts reviewing a test set for Knee3.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Given that the clinical validation relied on "literature" and not a bespoke test set with expert ground truth establishment for Knee3, no adjudication method is described or implied.
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
The document does not indicate that an MRMC comparative effectiveness study was done. The Knee3 is an "intraoperative localization system" and a "software application module" that "aids the surgeon to plan resections, measure cutting block alignment, measure bone resections, and/or leg alignment." It's a navigation system for surgery, not an AI for image interpretation that would typically involve human readers. Therefore, there is no mention of "human readers" or "AI assistance" in the context of improving their performance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The "technical navigation accuracy (bench accuracy)" measured on a "bench model" can be considered a form of standalone performance evaluation for the system's core accuracy without surgeon interaction on a patient. It showed the system to be "within limits of ± 2° for angles and ± 2mm for distances in 95% of cases."
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the "technical navigation accuracy," the ground truth was presumably physical measurements on a bench model, comparing the system's output to known, precisely measured values.
For the "clinical validation," the ground truth described as being derived from "clinical data gathered from literature" for predicate devices. This implies that the effectiveness and accuracy of the workflows were established through patient outcomes or established surgical accuracy metrics reported in prior clinical studies for those predicate devices. The exact nature of this "ground truth" (e.g., post-operative imaging, clinical assessments) is not detailed in this summary.
8. The sample size for the training set
The document does not mention a training set size. This device is described as a "software application module" and a "stereotaxic instrument" that links physical instruments to virtual models. While it undoubtedly has software components, the description does not explicitly state it utilizes machine learning or AI that would typically require a distinct training set for model development in the way that, for example, an image interpretation AI would. The "software verification and validation testing" refers to general software quality assurance, not a machine learning model's training.
9. How the ground truth for the training set was established
As no training set is described in the context of machine learning, there is no information on how ground truth for such a set was established.
{0}------------------------------------------------
Image /page/0/Picture/0 description: The image shows the logos of the Department of Health & Human Services and the Food and Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo is a blue square with the letters "FDA" in white, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue.
June 3, 2022
Brainlab AG Chiara Cunico Manager Regulatory Affairs Olof-Palme-Str. 9 Munich, Bavaria 81829 Germany
Re: K220652
Trade/Device Name: Knee 3 Regulation Number: 21 CFR 882.4560 Regulation Name: Stereotaxic Instrument Regulatory Class: Class II Product Code: OLO Dated: March 1, 2022 Received: March 7, 2022
Dear Chiara Cunico:
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
{1}------------------------------------------------
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,
Shumaya Ali, M.P.H. Assistant Director DHT6C: Division of Restorative, Repair and Trauma Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
{2}------------------------------------------------
Indications for Use
510(k) Number (if known) K220652
Device Name Knee 3
Indications for Use (Describe)
Knee3 is intended to be an intraoperative localization system used during orthopedic knee surgery. It links a navigated instrument, tracked by a passive marker sensor system, to virtual computer image space on an individually acquired model of the patient's anatomical axes, which are generated through acquiring multiple anatomical bony landmarks. The system is indicated for medical conditions in which the use of stereotaxic surgery may be appropriate and where a reference to a rigid anatomical structure, such as the femur and tibia, can be identified relative to the acquired anatomical landmarks. The system aids the surgeon to plan resections, measure cutting block alignment, measure bone resections, and/or leg alignment. The device is indicated for total and uni-compartmental knee replacement.
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!
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."
{3}------------------------------------------------
Image /page/3/Picture/1 description: The image shows the logo for Brainlab, a medical technology company. The logo consists of a stylized brain icon on the left, followed by the word "BRAINLAB" in bold, sans-serif font. The brain icon is composed of several curved lines, creating an abstract representation of the brain's structure.
510(k) Summary
May 25, 2022
| General Information | |
|---|---|
| Manufacturer | Brainlab AG; Olof-Palme Str.9, 81829, Munich, Germany |
| Establishment Registration | 8043933 |
| Device Name | Orthopedic Stereotaxic Instrument |
| Trade Name | Knee 3 |
| Classification Name | Stereotaxic instrument |
| Product Code | OLO |
| Regulation Number | 882.4560 |
| Regulatory Class | II |
| Panel | Orthopedic |
| Predicate Devices | Primary predicate device: Brainlab Knee (Knee 2.5) K102990Secondary predicate device: uni-Knee (Uni-Knee 2.0) K080678Tertiary predicate device: DASH Knee (DASH Knee 1.0) (K102251) |
| Contact Information | |
|---|---|
| Primary Contact | Alternate Contact |
| Chiara Cunico | Regulatory Affairs Brainlab |
| Manager RA | Phone: +49 89 99 15 68 0 |
| Phone: +49 89 99 15 68 0 | Fax: +49 89 99 15 68 5033 |
| Email: chiara.cunico@brainlab.com | Email: regulatory.affairs@brainlab.com |
1. Indications for Use
Knee3 is intended to be an intraoperative localization system used during orthopedic knee surgery. It links a navigated instrument, tracked by a passive marker sensor system, to virtual computer image space on an individually acquired model of the patient's anatomical axes, which are generated through acquiring multiple anatomical bony landmarks. The system is indicated for medical conditions in which the use of stereotaxic surgery may be appropriate and where a reference to a rigid anatomical structure, such as the femur and tibia, can be identified relative to the acquired anatomical landmarks. The system aids the surgeon to plan resections, measure cutting block alignment, measure bone resections, and/or leg alignment.
The device is indicated for total and uni-compartmental knee replacement.
{4}------------------------------------------------
Image /page/4/Picture/1 description: The image shows the Brainlab logo. The logo consists of a stylized symbol on the left and the word "BRAINLAB" in bold, sans-serif font on the right. The symbol appears to be a stylized representation of the brain.
2. Device Description
The Knee3 is a software application module intended to be used on compatible navigation platforms that assist in the implantation of prosthetic knee implants. It uses instruments and accessories such as reference arrays, pointers and plane tools, which are tracked by an infrared camera of the respective platform, to determine femur and tibia anatomical landmarks as well as instrument positions in relation to the registered bones. The resulting navigation measurements support the user with the placement of the cutting guides.
| TrackingPrinciple | Infrared passive and active marker based tracking as provided by theoptical tracking camera unit of the navigation station. |
|---|---|
| Navigation | The relation between the patient and the reference attached to the patientis realized with a manual registration using instruments.The Knee3 software receives position and orientation of tracked instrumentaccessories and calculates the navigation measurements out of theirrelations to each other. The measurement values are displayed within thesoftware graphical user interface on the respective platform screen. |
| Display | LCD display with capacitive dual touch technology. |
3. Substantial Equivalence
| Devices | Name (version) | K-Number | Manufacturer |
|---|---|---|---|
| Subject Device | Knee3 (Knee 3.3) | N/A | Brainlab AG |
| Primary Predicate | Brainlab Knee (Knee 2.5) | K102990 | Brainlab AG |
| Secondary Predicate | uni-Knee (Uni-Knee 2.0) | K080678 | Brainlab AG |
| Tertiary predicate | DASH Knee (DASH Knee 1.0) | K102251 | Brainlab AG |
COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE
Infrared optical tracking is the technological principle for both the subject and predicate devices. It is based on the use of instruments with reflective marker technology.
At a high level, the subject and predicate devices are based on the following same technological elements:
- Same localization and referencing techniques -
- Same user interface technology -
- Same remote control devices -
- Same general acquisition methods -
- Mostly the same registration steps that make up the bone coordinate systems -
- Instruments are made of surgical grade materials -
- Instruments are pre-calibrated -
The following technological differences exist between the subject and predicate devices:
- User interface visual design -
- -Software user guidance
Knee 3
510(k) Summary
{5}------------------------------------------------
Image /page/5/Picture/0 description: The image shows the word "BRAINLAB" in all capital letters. To the left of the word is a stylized logo that appears to be three curved lines stacked on top of each other. The text and logo are in black and the background is white.
- Some landmark registrations -
- -Compatible platform devices and accessories
However, these differences do not raise any new questions of safety or efficacy because the performance of the subject device has thoroughly been verified for its efficacy.
4. Performance Data
The following performance data were provided in support of the substantial equivalence determination.
System
The technical navigation accuracy (bench accuracy) of the overall system consisting of platform, software and instruments has been evaluated on a bench model and has shown to be within limits of ± 2° for angles and ± 2mm for distances in 95% of cases.
Instruments
The safety and effectiveness of the Knee3 Instruments has been verified. Technical performance has been tested on the following main aspects:
- . Instrument system integration testing: the Knee3 instruments have been proven to meet the accuracy requirements for use with Knee3.
- Mechanical stability testing: the mechanical stability of the Knee3 instruments has proven to ● be sufficient for the intended use.
- Biocompatibility: the Knee3 instruments with intended patient contact have been supported as ● biocompatible.
Biocompatibility testing
The biocompatibility evaluation for the Knee3 surgical instruments was conducted in accordance with the FDA Blue Book Memorandum #G95-1 "Use of International Standard ISO-10993, 'Biological Evaluation of Medical Devices Part 1: Evaluation and Testing," May 1, 1995, and International Standard ISO 10993-1 "Biological Evaluation of Medical Devices - Part 1: Evaluation and Testing Within a Risk Management Process," as recognized by FDA. The battery of testing included the following tests:
- Cytotoxicity tests acc. to ISO 10993-5 -
- Chemical analysis acc. to 10993-12 and 10993-18 for quantification and characterization of organic leachables and extractables
In addition, the following biological endpoints were evaluated based on the test results:
- -Sensitization acc. to ISO 10993-10
- Irritation acc. to ISO 10993-10 -
- -Materials-Mediated Pyrogenicity acc. to ISO 10993-11
{6}------------------------------------------------
Image /page/6/Picture/1 description: The image shows the logo for Brainlab. The logo consists of a stylized symbol on the left and the word "BRAINLAB" in all caps on the right. The symbol appears to be three interconnected shapes, possibly representing neurons or brainwaves. The text is in a bold, sans-serif font, giving the logo a modern and professional look.
- -Acute Systemic Toxicity acc. to ISO 10993-11
Software Verification and Validation Testing
Software verification and validation testing were conducted and documentation was provided as recommended by FDA's Guidance for Industry and FDA Staff. "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices." The software for this device was considered as a "major" level of concern, since failures or latent flaws could prior to mitigation of hazards result in serious injury to the patient. Information provided by the software drives a decision through the user, that, if misapplied, could result in serious injury.
Clinical Validation:
Clinical Validation for the Subject Device was carried out to establish equivalence of the subject device workflows (Motion, Universal, Partial and Express) to the workflows contained within the identified predicate devices.
Clinical data gathered from literature was used to validate the accuracy of the predecessor software device versions (predicate devices) and respective workflows.
5. Conclusion
The comparison of the Knee3 with the predicate device(s) Brainlab Knee, Uni Knee and DASH Knee shows that the Knee3 has similar functionality, intended use, technological characteristics, and typical users as the predicate devices. Verification activities ensured that the design specifications are met and that the Knee3 does not introduce new issues concerning safety and effectiveness. Hence, the Subject Device is substantially equivalent to the predicate device.
§ 882.4560 Stereotaxic instrument.
(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).