RESOFIX BIOABSORBABLE EXPANSION BOLT by RESOFIX, INC.

The Resofix® Bioabsorbable Expansion Bolt is a single-use, sterile implant that is intended for use in the interference fixation of bone-tendon-bone and soft tissue grafts in anterior and posterior cruciate ligament reconstruction.

Device Description

The Resofix product is a two-shell bioabsorbable expansion bolt, consisting of two shell halves, forming an expanding dowel system, and a central expansion wedge. Insertion of the expansion wedge between the dowel halves results in expansion over the full length of the implant. When expanded, 2/3 of the implant cross-section is round and 1/3 is flat. The surface of the implant is designed to maximize contact and maintain implant position, both immediately after being inserted, as well as during the absorption period. The Resofix® Bioabsorbable Expansion Bolt shell halves and expansion wedge are injection molded poly-D,L-lactide (PDLLA, Resomer 208), which is substantially equivalent to the material used by Sulzer Orthopedics Ltd. in its Sysorb interference screws, previously approved by the U.S. FDA (K983592). Included in the system are associated preparation and implantation instruments, which are exempt Class I instruments, per 21 CFR 888.4540, "Orthopaedic Manual Surgical Instruments". The Resofix PDLLA implants are available in two sizes (8mm x 28mm and 10mm x 35mm) and the 10mm units are available in two expansion options (2.2mm for bone-tendon-bone grafts and 2.9mm for semitendinosus gracilis grafts).

AI/ML Overview

The provided text is a compilation of FDA documents related to the Resofix® Bioabsorbable Expansion Bolt. It is important to note that these documents primarily discuss the device's intended use, description, potential risks, and the FDA's determination of substantial equivalence to a predicate device. They do not contain information about specific acceptance criteria or a detailed study proving the device meets those criteria, as one would find in a clinical trial report or a performance validation study.

The FDA's 510(k) clearance process, under which this device was approved, focuses on demonstrating "substantial equivalence" to a legally marketed predicate device, rather than proving independent performance against predefined acceptance criteria through a standalone study in the same way a PMA (Premarket Approval) would require.

Therefore, the requested information elements cannot be fully addressed from the provided text in the typical format of a device performance study. However, I can extract information related to the demonstration of substantial equivalence.

Here's an analysis based on the provided text, addressing the points where information is available or indicating where it is not:

Acceptance Criteria and Device Performance Study (Based on Substantial Equivalence)

The FDA clearance for the Resofix® Bioabsorbable Expansion Bolt (K043411) was based on demonstrating "substantial equivalence" to a legally marketed predicate device, the Arthrex "Bio-interference screw" (likely a misspelling of "Bio-interference Screw"). This means that the Resofix device was deemed to be as safe and effective as the predicate device for its intended use, without raising new issues of safety or effectiveness.

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

The provided text does not explicitly state specific quantitative acceptance criteria for performance (e.g., specific pull-out strength values, degradation rates, or clinical success rates). Instead, the "performance" is implicitly demonstrated through the claim of substantial equivalence to the predicate device.

Acceptance Criteria (Implicit from Substantial Equivalence to Predicate)	Reported Device Performance (as claimed in 510(k) submission)
Material Equivalence: Material properties similar to predicate.	Resofix uses injection molded poly-D,L-lactide (PDLLA, Resomer® 208), which is stated to be "substantially equivalent to the material used by Sulzer Orthopedics Ltd. in its Sysorb interference screws" (K983592) (a similar predicate).
Purpose/Intended Use Equivalence: Same indications for use as predicate.	Intended for interference fixation of bone-tendon-bone and soft tissue grafts in anterior and posterior cruciate ligament reconstruction, "similar in material and purpose to the Arthrex Bio-interference Screw."
Biomechanical Equivalence: Biomechanical properties do not raise new safety/effectiveness issues.	"Biomechanical testing confirms that differences in the Resofix® Bioabsorbable Expansion Bolt and predicate device, do not raise any new issues of safety or effectiveness." (Specific test results not detailed in provided text).
Safety Profile Equivalence: Similar potential risks as predicate.	Potential risks listed (e.g., loosening, fracture, laceration, infection, tissue reaction) are general to this type of device and implicitly comparable to predicate.

2. Sample size used for the test set and the data provenance:

Test Set Sample Size: The provided text does not specify a sample size for a "test set" related to clinical performance or a specific in-vivo study used to prove effectiveness. The statement "biomechanical testing confirms that differences... do not raise any new issues of safety or effectiveness" implies in-vitro testing. No details on the number of samples or specific tests performed are provided.
Data Provenance: The nature of the "biomechanical testing" (e.g., in-vitro, ex-vivo, animal model) and its origin (e.g., specific lab, country) are not detailed. It is likely a combination of bench testing and potentially literature review based on the predicate device's performance. The FDA approval document is from the U.S.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

Not Applicable. The 510(k) pathway for this medical device does not typically involve human expert adjudication of a "test set" in the context of diagnostic or AI performance, as it is based on physical and mechanical equivalence to an existing implant. Therefore, information regarding "number of experts" or their qualifications for establishing ground truth for a test set is not available or relevant for this type of device submission.

4. Adjudication method for the test set:

Not Applicable. As no "test set" requiring expert ground truth or adjudication is described in the provided documents, there is no adjudication method mentioned.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:

Not Applicable. This is a bioabsorbable fixation bolt, not a diagnostic imaging device or an AI-assisted diagnostic tool. Therefore, an MRMC study comparing human reader performance with or without AI assistance is not relevant and was not performed.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Not Applicable. This device is a physical implant, not a software algorithm. Therefore, "standalone" algorithm performance is not relevant and was not evaluated.

7. The type of ground truth used:

The "ground truth" for this device's equivalence relies on:
- Predicate Device History: The known safety and effectiveness profile of the legally marketed predicate device (Arthrex Bio-interference Screw and Sulzer Orthopedics' Sysorb interference screws).
- Engineering/Biomechanical Principles: The understanding that if the Resofix device has similar materials, design principles, and biomechanical performance to the predicate, it will also be safe and effective.
- Biomechanical Testing Data (undisclosed details): The submission claims "biomechanical testing confirms that differences... do not raise any new issues of safety or effectiveness." This implies laboratory-based, in-vitro testing where the "ground truth" would be the measured physical properties (e.g., tensile strength, shear strength, degradation rate) compared against established engineering standards or the predicate device's performance.

8. The sample size for the training set:

Not Applicable. This device is a physical implant, not an AI or machine learning model. Therefore, the concept of a "training set" is not relevant.

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

Not Applicable. As there is no "training set" for an AI/ML model, this question is not applicable.

Summary of what's provided for K043411:

The provided documents detail an FDA 510(k) clearance for a medical device:

Device Name: Resofix® Bioabsorbable Expansion Bolt
Classification: Class II, 21 CFR 888.3030 (Fastener, Fixation, Biodegradable, Soft Tissue)
Intended Use: Interference fixation of bone-tendon-bone and soft tissue grafts in anterior and posterior cruciate ligament reconstruction.
Mechanism of Clearance: Substantial Equivalence to predicate devices (Arthrex Bio-interference Screw, Sulzer Orthopedics Ltd. Sysorb interference screws).
Key Evidence for Equivalence:
- Material composition (PDLLA) similar to an already approved material.
- Similar intended use to predicate.
- "Biomechanical testing confirms that differences... do not raise any new issues of safety or effectiveness." (Specifics of this testing are not included in the provided excerpts).
No detailed performance study with specific acceptance criteria, sample sizes for test/training sets, expert adjudication, or MRMC studies are included in these 510(k) summary documents. Such details would typically be found in the actual submission package, which is generally not publicly released in its entirety.

Summary

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SUMMARY OF SAFETY AND EFFECTIVENESS

Confidential

KO44411

Sponsor: Resofix. Inc. 5349 Red Leaf Court Oviedo. Florida 32765

Resofix® Bioabsorbable Expansion Bolt Device:

Classification Name: 21 CFR 888.3030 Fastener, Fixation, Biodegradable, Soft Tissue -Class II
Intended Use: The Resofix® Bioabsorbable Expansion Bolt is a single-use, sterile implant that is intended for use in the interference fixation of bone-tendon-bone and soft tissue grafts in anterior and posterior cruciate ligament reconstruction.

Device Description: The Resofix product is a two-shell bioabsorbable expansion bolt, consisting of two shell halves, forming an expanding dowel system, and a central expansion wedge. Insertion of the expansion wedge between the dowel halves results in expansion over the full length of the implant. When expanded, 2/3 of the implant cross-section is round and 1/3 is flat. The surface of the implant is designed to maximize contact and maintain implant position, both immediately after being inserted, as well as during the absorption period. The Resofix® Bioabsorbable Expansion Bolt shell halves and expansion wedge are injection molded poly-D,L-lactide (PDLLA, Resomer 208), which is substantially equivalent to the material used by Sulzer Orthopedics Ltd. in its Sysorb interference screws, previously approved by the U.S. FDA (K983592). Included in the system are associated preparation and implantation instruments, which are exempt Class I instruments, per 21 CFR 888.4540, "Orthopaedic Manual Surgical Instruments". The Resofix PDLLA implants are available in two sizes (8mm x 28mm and 10mm x 35mm) and the 10mm units are available in two expansion options (2.2mm for bone-tendon-bone grafts and 2.9mm for semitendinosus gracilis grafts).

Potential Risks: Possible adverse effects include -

Loosening, cracking or fracture of the bolt, which may be caused by insufficient . quality or quantity of base bone stock.
Fracture of the femur or tibia caused by improper bolt placement. .
Laceration of the graft material, which would most likely be caused by operative . instruments.
Failure of the graft material to thrive following reconstruction. Although such a . situation is rare, it may lead to dissolution of the graft material and recurrent instability of the knee.
Acute or late infection and low grade synovitis. .
Cardiovascular disorders, including wound hematoma and thromboembolic disease. .
Tissue reaction, including macrophage and foreign body reactions adjacent to the . bolt.

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Confidential
page 12

Substantial Equivalence:

The Resofix® Bioabsorbable Expansion Bolt is similar in material and purpose to the Arthrex The I (coolix's Bloads on been previously cleared by the Food and Drug Dio-interference Oorcw which has been phone-lendon-bone and soft tissue grafts in ACL Administration for internetion, biomechanical testing confirms that differences in and TOL resofix® Bioabsorbable Expansion Bolt and predicate device, do not raise any new issues of safety or effectiveness.

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Mr. Carl Knobloch Chief Operating Officer Resofix, Inc. 5349 Red Leaf Court Oviedo, Florida 32765

Re: K043411

Trade/Device Name: Resofix® Bioabsorbable Expansion Bolt Regulation Number: 21 CFR 888.3030 Regulation Name: Single/multiple component metallic bone fixation appliances and accessories Regulatory Class: II Product Code: HTN Dated: December 2, 2004 Received: December 13, 2004

FEB 1 7 2005

Dear Mr. Knobloch:

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 FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the clectronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 - Mr. Carl Knobloch

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 (240) 276-0120. 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/industry/support/index.html

Sincerely yours,

Mark N. Wilkinson

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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page 1 of

Confidential

INDICATIONS FOR USE

510(k) Number (if known): K043411

Device Name: Resofix® Bioabsorbable Expansion Bolt

Indications for Use: The Resofix® Bioabsorbable Expansion Bolt is a single-use, sterile implant that is intended for use in the interference fixation of bone-tendon-bone and soft tissue grafts in anterior and posterior cruciate ligament reconstruction.

(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) X

Over-the-Counter Use (Optional Format 1-2-96)

Mark N. Mulker

3 318 torative. 200

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Regulation Number and Section

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

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