CAP GREAT TOE RESURFACING HEMI-ARTHROPLASTY IMPLANT
K031859 · Arthrosurface, Inc. · KWD · Feb 18, 2004 · Orthopedic
Device Facts
Record ID
K031859
Device Name
CAP GREAT TOE RESURFACING HEMI-ARTHROPLASTY IMPLANT
Applicant
Arthrosurface, Inc.
Product Code
KWD · Orthopedic
Decision Date
Feb 18, 2004
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 888.3730
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
Hemi arthroplasty implant for first metatarsophalangeal joint for use in the treatment of patients with degenerative and post-traumatic arthritis in the first metatarsal joint in the presence of good bone stock along with the following clinical conditions; hallux valgus or hallux limitus, hallux rigidus, and an unstable or painful metatarsal/phalangeal (MTP) joint. The device is a single use implant intended to be used with bone cement.
Device Story
CAP™ Great Toe Resurfacing Hemi-arthroplasty is a 2-piece modular implant for first MTP joint arthroplasty. Components include a Ti-6Al-4V ELI taper post and a cobalt-chrome-molybdenum articular component with CP titanium coating. Surgeon uses provided instrumentation (drill guide, contact probe) to define a working axis, measure articular topography, and select an appropriately sized articular component. The device is implanted using bone cement. The system minimizes bone resection compared to traditional implants, aiming to restore physiological load distribution. Used in clinical settings by orthopedic surgeons to treat arthritis and joint instability/pain. Benefits include precise anatomical fit, joint surface resurfacing, and preservation of bone for potential future procedures.
Clinical Evidence
Bench testing only. No clinical data provided. Mechanical testing included axial assembly/disassembly, rigidity characterization, cyclic fatigue, fretting/corrosion (ASTM F897), and torque resistance (ISO 7206-9). Surface coating performance referenced via Master Device File MAF-1085.
Technological Characteristics
2-piece modular implant. Taper post: Ti-6Al-4V ELI (ASTM F136). Articular component: Cobalt-Chromium-Molybdenum (ASTM F799, ASTM F1537) with CP Titanium plasma spray coating. Fixation: Bone cement. Mechanical taper interlock. Instrumentation includes drill guide and contact probe for anatomical sizing.
Indications for Use
Indicated for patients with degenerative or post-traumatic arthritis of the first metatarsophalangeal joint with good bone stock, including hallux valgus, hallux limitus, hallux rigidus, or unstable/painful MTP joint.
Regulatory Classification
Identification
A toe joint phalangeal (hemi-toe) polymer prosthesis is a device made of silicone elastomer intended to be implanted to replace the base of the proximal phalanx of the toe.
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K031859 pg
510(k) Premarket Notification CAP™ Great Toe Resurfacing Hemi-arthroplasty Implant
# 510(K) SUMMARY OF SAFETY AND EFFECTIVENESS (21 CFR 807.92) [21 CFR 807.87(H)]
# CAP™ GREAT TOE RESURFACING HEMI-ARTHROPLASTY IMPLANT
In accordance with the Food and Drug Administration Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21 CFR 807.87(h), this information serves as a Summary of Safety and Effectiveness for the CAP™ Great Toe Resurfacing Hemi-arthroplasty implant.
| Submitted By: | STD Manufacturing, Inc.<br>1063 Turnpike Street<br>Stoughton, MA 02072<br>(781) 828-4400 |
|-------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Date: | May 30, 2003 |
| Contact Person: | Steven W. Ek, VP of Development |
| Proprietary Name: | CAP™ Great Toe Resurfacing Hemi-arthroplasty<br>implant |
| Common Name: | Toe joint, Phalangeal (hemi-toe) prosthesis |
| Classification Name: | Toe joint phalangeal (hemi-toe) prosthesis |
| Device Classification: | Class II |
| Review Panel: | Orthopedic |
| C.F.R. identification<br>reference: | 21 CFR § 888.3730 (2002) |
| Product Code: | KWD |
| Indications for Use: | Hemi arthroplasty implant for first<br>metatarsophalangeal joint for use in the treatment<br>of patients with degenerative and post-traumatic<br>arthritis in the first metatarsal joint in the presence<br>of good bone stock along with the following clinical<br>conditions; hallux valgus or hallux limitus, hallux |
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rigidus, and an unstable or painful metatarsal/phalangeal (MTP) joint. The device is a single use implant intended to be used with bone cement.
Substantial Equivalence Information:
The intended use, materials, and application of the Proposed device are substantially equivalent to those of the predicate devices. In determining substantial equivalence. STD Manufacturing's device. CAP™ Great Toe Resurfacing Hemi-arthroplasty implant, has been compared with the following legally marketed device to which the submitter claims equivalence.
- Implant, H.P. condylar, Dow Corning Wright (K781870) .
- � Swanson Titanium Great Toe Implant, Dow Corning Wright (K864492)
- . K2 Hemi-Toe Implant System, Kinetikos Medical, Inc. (K023770)
- Futura Biomedical Metal Hemi Toe Implant, Futura Biomedical((K971047) .
- . Townley Great Toe Joint, Biopro, Inc.(K911378)
## Device Description and Implantation Summary
The CAP™ Great Toe Resurfacinq Hemi-arthroplasty implant is a cobalt chrome alloy, 2-piece implant to supplement first metatarsal phalangeal joint arthroplasty. The implant is designed to provide a smooth surface for the first metatarsophalangeal joint as a the treatment of patients with degenerative and post-traumatic arthritis in the first metatarsal joint in the presence of good bone stock along with the following clinical conditions; hallux valqus or hallux limitus, hallux rigidus, and an unstable or painful metatarsal/phalangeal (MTP) joint. The device is a single use implant intended to be used with bone cement.
The CAP™ Great Toe Resurfacing Hemi-arthroplasty implant consists of two components, a taper post component and an articular component, that mate together via a taper interlock to provide stable and immobile fixation of the implant and stress bearing contact at the bone/prosthetic interface.
The first implant component is a Taper Post manufactured of a Ti-6AI-4V ELI alloy per ASTM F136. The Taper Post has a tapering distal tip, a full-length cannulation, and a proximal female taper bore.
The second implant is an articular component manufactured of a Cobalt-Chromium-Molybdenum alloy per ASTM F799 and ASTM F1537. The articular component has a bone contact surface that is coated with a CP Titanium coating
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K031859
page 2 of 6
and a polished articular bearing surface. For greater detail, refer to section 8.2 to view engineering drawings illustrating the various components.
Utilizing the drill guide provided within the CAP™ Great Toe Resurfacing Hemiarthroplasty implant instrumentation set, a surgeon is able to define a working axis that is normal to the articular cartilage surface at the site of the defect. After drilling a pilot hole, theTaper Post is screwed into place using the trial cap to ensure that the surface of the articular component will be tangent and congruent to the existing cartilage surface when seated. Using the contact probe instrument to the explant diameter, offset measurements are taken to define the topography of the patients surrounding articular surface by revolving the probe around a centering shaft coaxial to the working axis of the Taper Post. With these offset measurements, the surgeon is able to select the articular component (sized to match great toe metatarsal head) that will allow it to seat flush to the surrounding articular surface. Offset increments in .5mm sizes will allow for an optimal fit to the existing articular surface.
A reamer, which matches the articular component internal geometry is used to prepare the site for the prosthetic to be implanted. This allows for a precise fit of the implant to the prepared site and minimizes bone resection, so as to provide minimal impact to any future arthroplasty procedure. The articular component is then impacted to seat the taper interlock between the two components.
The prosthetic is intended to provide an effective means for treatment of patients with degenerative and post-traumatic arthritis, hallux valgus, hallux rigidus, hallux limitus, and/or an unstable or painful metatarsal/phalangeal (MTP) joint.
The device has been designed to offer a number of clinical benefits to the user and patient. The device is technically easy to implant, and offers the surgeon a high degree of precision and flexibility in sizing and fitting the articular component to the existing anatomy. A reduction in bone and articular cartilage resection is also offered over the predicate devices, providing a more physiologically normal joint in terms of load and impact distribution.
### Non-clinical Testing conducted to determine substantial equivalence with the predicate devices
Mechanical test protocol has been completed using the proposed device including testing of the taper post component and the articular component per the guidelines established in CDRH Guidance Document for Testing Non-Articulating, Mechanically Locked, Modular Implant Components and ASTM F 1814 "Standard Guide for Evaluating Modular Hip and Knee Joint Components".
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K031859
page 4 of 6
The following non-clinical tests were conducted to assess the device performance:
- Axial Assembly and Disassembly .
- Rigidity Characterization �
- Cyclic Fatigue Failure, Disassembly �
- Fretting, Fretting/ Corrosion (ASTM F897) .
- Resistance to Torque of Head Fixation" (ISO 7206-9) .
Final results from these tests demonstrate that the devices meet established acceptance criteria in accordance with the identified industry standards.
Testing to document the required information for the vacuum plasma spray applied surface coating has been previously performed per guidelines established in CDRH Guidance Document for Testing Orthopedic Implants with Modified Metallic Surfaces Apposing Bone or Cement. This documentation exists in the Bio-Coat Master Device File MAF-1085 of which Arthrosurface has been qiven authorization to reference in support of this 510(k) submission.
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t) Premarket Notification
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K031859
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End of 510(K) Summary of Safety and Effectiveness
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized image of a human figure with three wavy lines extending from the figure's head, representing the department's mission to protect and promote the health and well-being of Americans.
Public Health Service
FEB 1 8 20014
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
Mr. Steven Ek Chief Operating Officer Arthrosurface, Inc. 378 Page Street, Unit 6 Stoughton, MA 02072
Re: K031859
Trade/Device Name: CAP™ Great Toe Resurfacing Hemi-arthroplasty Regulation Number: 21 CFR 888.3730 Regulation Name: Toe joint phalangeal (hemi-toe) polymer prosthesis Regulatory Class: Il Product Code: KWD Dated: November 18, 2003 Received: November 20, 2003
Dear Mr. Fk:
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.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such 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 IDA 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); good manufacturing practice requirements as set 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.
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#### Page 2 - Mr. Steven Ek
This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97) you may obtain. Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html
Sincerely yours.
Sincerely yours,
Mark McMillan
Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Number: K031859
Device Name: CAP™ Great Toe Resurfacing Hemi-arthroplasty
Indications for Use:
Hemi-arthroplasty implant for first metatarsophalangeal joint for use in the treatment of patients with degenerative and post-traumatic arthritis in the first metatarsal joint in the presence of good bone stock along with the following clinical conditions; hallux valgus or hallux limitus, hallux rigidus, and an unstable or painful metatarsal/phalangeal (MTP) joint. The device is a single use implant intended to be used with bone cement.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use (Per 21 CFR 801.109 Over-The Counter Use
(Optional Format 1-2-96)
Mark N. Melleuson
Division Sign Off
Division of General, Restorative, and Neurological Devices
**510(k) Number** K031854
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
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.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
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.
What does the AI Performance sub-table show, and why is it useful?
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.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
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.
What does the side-by-side PDF viewer mode do?
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.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
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.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
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.
10. Embeddings: the galaxy map
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.