The WITTENSTEIN intens GmbH FITBONE® TAA intramedullary lengthening system is intended for limb lengthening of the femur and tibia. The FITBONE®TA A intramedullary lengthening system is indicated for adult and pediatric (greater than 12 through 21 years of age) patients.
Device Story
Fully implantable intramedullary lengthening system; used for femur/tibia lengthening. Device consists of telescoping nail, hermetically enclosed electromagnetic motor, gear/spindle mechanism, subcutaneous receiver, and external control electronics with transmitter. Surgeon implants nail into medullary canal; fixes with locking screws. Patient triggers distraction process by placing external transmitter over subcutaneous receiver and pressing button on control unit. Motor rotation converts to axial movement via gear/spindle, extending nail. Used in operating theatre and home environment. Output is controlled mechanical distraction; benefits patient by enabling limb lengthening. No transcutaneous contact between nail and body surface.
Clinical Evidence
Bench testing only. No clinical data presented. Substantial equivalence supported by engineering, electrical, and human factors testing demonstrating performance equivalent to predicate devices.
Technological Characteristics
Intramedullary lengthening nail; stainless steel AISI 316LVM (ASTM F138-13) locking screws; medical grade stainless steel, aluminum, and silicone instruments. Electromagnetic motor actuation; gear/spindle mechanism. Sterile implant components; non-sterile external electronics. Standalone system with external transmitter/receiver energy transmission.
Indications for Use
Indicated for limb lengthening of femur and tibia in adult and pediatric patients aged >12 to 21 years.
Regulatory Classification
Identification
An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures.
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February 17, 2021
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: on the left, there is a seal with an abstract design, and on the right, there is the text "FDA U.S. FOOD & DRUG ADMINISTRATION" in blue. The text is arranged in three lines, with "FDA" in a larger font and enclosed in a blue square.
WITTENSTEIN intens GmbH % Cheryl Wagoner Consultant Wagoner Consulting LLG P O Box 15729 Wilmington, North Carolina 28408
Re: K203399
Trade/Device Name: FITBONE® TAA Regulation Number: 21 CFR 888.3020 Regulation Name: Intramedullary fixation rod Regulatory Class: Class II Product Code: HSB Dated: November 16, 2020 Received: November 19, 2020
Dear Cheryl Wagoner:
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,
Michael Owens Assistant Director DHT6A: Division of Joint Arthroplasty Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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## Indications for Use
510(k) Number (if known) K203399
Device Name FITBONE® TAA
Indications for Use (Describe)
The WITTENSTEIN intens GmbH FITBONE® TAA intramedullary lengthening system is intended for limb lengthening of the femur and tibia.
The FITBONE®TA A intramedullary lengthening system is indicated for adult and pediatric (greater than 12 through 21 years of age) patients.
Type of Use (Select one or both, as applicable):
| <div style="display:inline-block;">☑</div> | |
|--------------------------------------------|--|
| <div style="display:inline-block;">☐</div> | |
X Prescription Use (Part 21 CFR 801 Subpart D)
| Over-The-Counter Use (21 CFR 801 Subpart C)
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# 510(K) SUMMARY
### Submitter information
| Company Name: | WITTENSTEIN intens GmbH |
|---------------|----------------------------------------------------------|
| Address | Walter-Wittenstein-Strasse 1<br>97999 Igersheim, Germany |
| Telephone | +49 7931 493 0 |
| Fax | +49 7931 493 10906 |
| Contact Person | Hartmut Kampa<br>General Manager |
|--------------------|----------------------------------------------------------|
| Address | Walter-Wittenstein-Strasse 1<br>97999 Igersheim, Germany |
| Telephone | +49 7931 493 10690 |
| Fax | +49 7931 493 710690 |
| Email address | hartmut.kampa@wittenstein.de |
| Date of submission | November 18, 2020 |
## Trade Name. Common Name. Classification
| Trade Name: | FITBONE® TAA |
|----------------------|-----------------------------------------------|
| Common Name: | Rod, Fixation, Intramedullary and Accessories |
| Classification Name: | Intramedullary fixation rod |
| Regulation Number: | 21 CFR 888.3020 |
| Product Code: | HSB |
| Classification: | Class II |
| Panel code: | Orthopedic |
### Predicate devices and reference devices
| Primary Predicate | 510(k) Number | Manufacturer |
|----------------------------------------------------|--------------------|-------------------------------------------------------------------------|
| FITBONE® TAA | K163368 | WITTENSTEIN intens GmbH |
| Additional Predicate | | |
| PRECICE® Intramedullary Limb<br>Lengthening System | K133289<br>K131677 | Ellipse Technologies (now:<br>NuVasive Specialized<br>Orthopedics Inc.) |
| Reference Devices | | |
| Fassier Duval Telescopic IM Nail<br>System | K020885 | Pega Medical, Inc. |
| PRECICE® Plating System | K192181 | NuVasive Specialized<br>Orthopedics Inc. |
| Device description | The FITBONE® TAA System is a fully implantable intramedullary lengthening device. Changes to the existing FITBONE® TAA (K163368) have been introduced to extend the current portfolio by new Subject |
|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| Indications for use |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| FITBONE® TAA09 intramedullary lengthening nail model fixed to the bone by new Subject Locking Screws and a new Subject Receiver connected to the Subject nail by a bipolar feed line with new Subject external Retraction Control Set consisting of a control electronics with a Retraction Transmitter. New Subject surgical tools are provided to facilitate the surgical process.<br><br>The Subject FITBONE® TAA09 intramedullary lengthening nail model, line extension of the primary predicate FITBONE® TAA (Κ163368) models is implanted into the medullary canal of the femur or tibia. The nail is fixed to the bone by Locking Screws through longitudinal openings in the nail.<br><br>The Subject FITBONE® TAA09 intramedullary lengthening nail consists of a telescoping system that allows it to expand. It is powered by hermetically enclosed electromagnetic motor which draws the telescope apart, during which the extension is externally steered via electronic impulses. The Subject FITBONE® TAA09 intramedullary lengthening nail elongation is propelled by a highly sensitive gear and spindle mechanism which converts the rotation of the motor into an axial movement with high force.<br><br>The energy needed for the distraction process of the nail is transmitted from the outside by placing the external Transmitter over the implanted Receiver which is placed in the subcutaneous tissue during FITBONE® surgery. The energy transmission will be triggered by pressing the "Patient" button on the control electronics by the patient. There is no transcutaneous contact between the implanted intramedullary nail and the outer surface of the patient's body.<br><br>The nail and Receiver are offered in sterile conditions and the Locking screws and non-implantable external electronic controlling components in non-sterile packaging configurations.<br><br>The Subject FITBONE® TAA09 nail model is fixed to the bone by Locking Screws, made from Stainless steel AISI 316LVM, according to ASTM F138-13 "Standard Specification for Wrought 18Chromium-14Nickel-2.5Molybdenum Stainless Steel Bar and Wire for Surgical Implants (UNS S31673)".<br><br>Surgical procedures with the use of the Subject FITBONE® TAA09 model shall be performed with the support of orthopedic instrumentation, to facilitate their proper insertion and removal from the patient. The surgical instruments offered by WITTENSTEIN intens GmbH as part of this submission under product code: LXH (21 CFR 888.4540).<br><br>The orthopedic instruments are made by medical grade stainless steel, Aluminum and Silicone.<br><br>The Subject FITBONE® TAA09 and the Subject external electronic controlling components are designed to be used in the operating theatre and home environment.<br><br>The WITTENSTEIN intens GmbH FITBONE® TAA intramedullary lengthening system is intended for limb lengthening of the femur and tibia. |
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| | The FITBONE®TAA intramedullary lengthening system is indicated for<br>adult and pediatric (greater than 12 through 21 years of age) patients. |
|----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Technological<br>Characteristics | The Subject device fundamental scientific principles and technological<br>characteristic, including: the intended use, material and general design,<br>are the same as, or similar to, FITBONE® TAA - K163368 and the<br>chosen additional predicate device.<br>Summary of the technological characteristics:<br>✓ Intended use: identical to FITBONE® TAA K163368 and additional predicate<br>✓ Indications for Use, Anatomical sites, operating principles and<br>conditions of use are substantially equivalent to FITBONE® TAA<br>K163368 and to the additional predicate. No new risks associated<br>to the Subject device compared to those of the additional predicate<br>and the reference devices which have similar indications for use,<br>anatomical sites and conditions of use. Verification activities on<br>Subject devices demonstrated the same safety and effectiveness<br>performs equivalent to the predicate devices.<br>✓ Material: are equivalent as the primary predicate.<br>✓ Geometry and size: similar sizes and geometry of the nails; similar<br>sizes and geometry of the Locking Screws.<br>✓ Sterilization: identical method as the FITBONE® TAA- K163368.<br>The technological characteristics of the Subjects FITBONE® TAA are<br>substantially equivalent to the FITBONE® TAA K163368 and predicate device. |
| Performance<br>Analysis | Subject devices have similar configuration, material, sizes and design<br>as to FITBONE® TAA K163368 and the predicate device.<br>Results to support the determination of substantial equivalence from<br>engineering, electrical, bench, human factors testing of the Subject<br>devices, confirm that Subject devices are as safe, as effective, and<br>performs as well as or better than the predicate devices.<br>Any potential hazards of the changes introduced to FITBONE® TAA<br>K163368 have been evaluated and controlled through Risk<br>Management activities, and any relevant information, have been<br>addressed in the labelling, after all control measures have been<br>implemented. |
| Conclusion | Based upon equivalences in: intended use, patient population, site of<br>application, conditions of use, operating principles, and the non-clinical<br>performance data, the changes introduced in the FITBONE® TAA<br>(K163368) for the new model FITBONE® TAA09 Subject nail and the<br>additional Subject components have been shown to be safe and<br>effective and to perform equivalently as compared to the legally<br>marketed predicate devices.<br>Therefore, the changes to FITBONE® TAA (K163368) for Subject<br>devices are substantially equivalent to the legally marketed predicate devices. |
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1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
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Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
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Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
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Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
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Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
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Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
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Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
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Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
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The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.