The TOWNLEY™ Transfacetpedicular Screw Fixation System is intended to stabilize the spine as an aid to fusion by two different fixation methods. The first fixation method uses the TOWNLEY™ Transfacetpedicular Screws as just facet fixation screws, where the screws are inserted bilaterally through the superior side of the facet, across the facet joint at (usually) a single level, and into the pedicle.

In the second fixation method, the TOWNLEY™ Transfacetpedicular Screws are inserted bilaterally through the superior side of the facet, across the facet joint, and into the pedicle at multiple levels at the same time that a DYNALOK® Plate is attached to the base of the spinous processes at the corresponding levels with TOWNLEY™ Transfacetpedicular Screws. The second fixation method should be used when the spine has increased instability or multiple levels need to be fused. Bone graft must be used for both fixation methods.

For both methods, this system is indicated for the posterior surgical treatment of any or all of the following at the C2 to T3 (inclusive) spinal levels: 1) Trauma, including spinal fractures and/or dislocations; 2) Spondylolisthesis; 3) Spondylolysis; 4) Pseudarthrosis or failed previous fusions which are symptomatic or which may cause secondary instability or deformity; 5) Degenerative diseases which include: (a) degenerative disc disease (ddd) as defined by neck and/or back pain of discogenic origin as confirmed by patient history with degeneration of the disc as confirmed by radiographic studies and/or: (b) degenerative disease of the facets with instability.

Device Description

The TOWNLEY™ Transfacetpedicular Screw Fixation System consists of screws designed to compress bone grafts. Both cortical and cancellous screw threads are available. The screws are fabricated from medical grade stainless steel described by such standards as ASTM F-138 or ISO 5832-1 or ISO 5832-9, or of titanium alloy described by such standards as ASTM F-136 or ISO 5832-3. The screws may or may not be used in conjunction with DYNALOK plates. When DYNALOK plates are used they are used to connect two or more screws together on one side of the spine at the base of the spinous process when the system is used for the second fixation method described below. Stainless steel and titanium implant components should never be used in the same construct. The sole purpose of this submission is to reduce the indications of the system.

AI/ML Overview

This documentation is a 510(k) summary for the TOWNLEY™ Transfacetpedicular Screw Fixation System, which is a medical device. 510(k) submissions typically demonstrate substantial equivalence to a predicate device rather than presenting a study proving performance against acceptance criteria in the way an AI/software device would. Therefore, most of the requested information regarding acceptance criteria, study design, and performance metrics for AI/software devices is not present in this type of document.

Here's an analysis based on the provided text:

1. Table of acceptance criteria and reported device performance:

This section is not applicable in the context of a 510(k) summary for a physical medical device like a screw fixation system. Acceptance criteria and reported performance metrics (like sensitivity, specificity, AUC) are typically associated with performance studies for diagnostic or AI/software devices. For this device, "acceptance" is primarily related to demonstrating substantial equivalence to a legally marketed predicate device.

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

Not applicable. No test set in the conventional sense of a clinical or performance study for an AI/software device is mentioned. The submission is based on demonstrating equivalence rather than a new performance study.

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

Not applicable. Ground truth establishment is not relevant in the context of a 510(k) summary for a physical implantable device.

4. Adjudication method for the test set:

Not applicable. No adjudication process for a test set is described.

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 device is a physical implant, not an AI or software device that would assist human readers.

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 an algorithm.

7. The type of ground truth used:

Not applicable. Ground truth is not a concept applied to the evaluation of this type of device in a 510(k) submission.

8. The sample size for the training set:

Not applicable. Training sets are associated with machine learning models, not physical medical devices.

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

Not applicable. As above, this concept does not apply to this device submission.

Summary of what is stated in the document regarding "acceptance":

The "acceptance" in this context refers to the FDA's decision that the device is substantially equivalent to a legally marketed predicate device.

Acceptance Criteria (Implicit for a 510(k) submission):
- Demonstrate that the new device has the same intended use as the predicate device.
- Demonstrate that the new device has the same technological characteristics as the predicate device, OR
- Demonstrate that if there are different technological characteristics, they do not raise different questions of safety and effectiveness, AND
- The device is as safe and effective as the predicate device.
Study Proving Acceptance (as described in the document):
The document states:
- "V. Substantial Equivalence: Documentation was provided which demonstrated the TOWNLEY™ Transfacetpedicular Screw Fixation System to be substantially equivalent to itself."
  This statement implies that the predicate device is an earlier version or iteration of the TOWNLEY™ Transfacetpedicular Screw Fixation System, and the current submission primarily aims to reduce the indications for the system, suggesting a re-evaluation or refinement of its approved uses rather than a completely new device. The FDA's letter explicitly states, "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... ".

In essence, the "study" for this 510(k) was a comparison to a predicate device (in this case, itself) to demonstrate that it continues to meet the requirements for marketing for its specified (and refined) indications. No new clinical performance data is mentioned in this summary; rather, the focus is on the device's design, materials, and intended use in relation to an already approved version.

Summary

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CONFIDENTIAL

JUL 2 4 2002

TOWNLEY™ Transfacetpedicular Screw Fixation System

510(k) Summarv May 2002

I. Company: Medtronic Sofamor Danek USA. Inc. 1800 Pyramid Place Memphis. TN 38132 (901) 396-3133
021705
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Proprietary Trade Name: TOWNLEY™ Transfacetpedicular Screw Fixation System II.
Product Descriptiom: The TOWNLEY™ Transfacetpedicular Screw Fixation System consists of III. screws designed to compress bone grafts. Both cortical and cancellous screw threads are available. The screws are fabricated from medical grade stainless steel described by such standards as ASTM F-138 or ISO 5832-1 or ISO 5832-9, or of titanium alloy described by such standards as ASTM F-136 or ISO 5832-3. The screws may or may not be used in conjunction with DYNALOK plates. When DYNALOK plates are used they are used to connect two or more screws together on one side of the spine at the base of the spinous process when the system is used for the second fixation method described below. Stainless steel and titanium implant components should never be used in the same construct. The sole purpose of this submission is to reduce the indications of the system.
Indications: The TOWNLEY™ Transfacetpedicular Screw Fixation System is intended to stabilize IV. the spine as an aid to fusion by two different fixation methods. The first fixation method uses the TOWNLEY™ Transfacetpedicular Screws as just facet fixation screws, where the screws are inserted bilaterally through the superior side of the facet, across the facet joint at (usually) a single level, and into the pedicle.

In the second fixation method, the TOWNLEY™ Transfacetpedicular Screws are inserted bilaterally through the superior side of the facet, across the facet joint, and into the pedicle at multiple levels at the same time that a DYNALOK @ Plate is attached to the spinous processes at the corresponding levels with TOWNLEY™ Transfacetpedicular Screws. The second fixation method should be used when the spine has increased instability or multiple levels need to be fused. Bone graft must be used for both fixation methods.

For both methods, this system is indicated for the posterior surgical treatment of any or all of the following at the C2 to T3 (inclusive) spinal levels: 1) Trauma, including spinal fractures and/or dislocations: 2) Spondylolisthesis: 3) Spondylolysis: 4) Pseudarthrosis or failed previous fusions which are symptomatic or which may cause secondary instability or deformity; 5) Degenerative diseases which include: (a) degenerative disc disease (ddd) as defined by neck and/or back pain of discogenic origin as confirmed by patient history with degeneration of the disc as confirmed by radiographic studies and/or; (b) degenerative disease of the facets with instability.

V. Substantial Equivalence: Documentation was provided which demonstrated the TOWNLEY™ Transfacetpedicular Screw Fixation System to be substantially equivalent to itself.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Public Health Service

Image /page/1/Picture/2 description: The image shows the logo for the Department of Health & Human Services - USA. The logo is circular, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. In the center of the circle is an emblem featuring three stylized human profiles facing to the right, stacked on top of each other.

JUL 2 4 2002

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Richard W. Treharne, Ph.D. Vice President Research and Regulatory Affairs Medtronic Sofamor Danek 1800 Pyramid Place Memphis. Tennessee 38132

Re: K021705

Trade/Device Name: TOWNLEY™ Transfacetpedicular Screw Fixation System Regulatory Class: unclassified Product Code: MRW Dated: June 20, 2002 Received: June 25, 2002

Dear Dr. Treharne:

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 electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 - Richard W. Treharne, Ph.D.

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 and additionally 21 CFR Part 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594- . Additionally, for questions on the promotion and advertising of your device, 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). 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,

Mark H. Milkeerson

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 1

May 2002

510(k) Number (if known):

Device Name: TOWNLEY™ Transfacetpedicular Screw Fixation System

Indications for Use:

(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) OR

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

Mark N Milbern

and Neurological Dev

510(k) Number K021705

Regulation Number and Section

N/A