(119 days)
The Townley Tranfacet/Intrapedicular Screw is intended to stabilize the spine as an aid to fusion through bilateral immobilization of the facet joints. The screws are inserted posteriorly through the superior side of the facet, across the facet joint, and into the pedicle. The Townley Screw is indicated for bilateral facet fixation, with or without bone graft, at single or multiple levels, and from C2 to S1, for treatment of any or all of the following: pseudoarthrosis and failed previous fusion; spondylolisthesis; spondylolysis; degenerative disc disease (DDD) as defined by neck and/or back pain of discogenic origin as confirmed by radiographic studies; degeneration of the facets with instability; and fracture
The Townley Trunfacet/Intrapedicular Screw consists of a broad-headed, partially threaded screw designed to compact juxtaposed facet articular processes to enhance spinal fusion and stability. The non-threaded portion facilitates compression of the joint surfaces through a gliding hole technique. The screws are available fabricated from medical grade stainless steel (ASTM F-138) or Ti6Al4V alloy (ASTM F136 or 1472), and are supplied in various lengths ranging from 25 mm (approx. 0.98") to 60 mm (approx. 2.37"). In all sizes, the screws have a major diameter of 3.5 mm (approx. 0.140") and a minor diameter of 2.70 mm (approx. 0.106").
The provided text describes a 510(k) submission for the Townley Transfacet/Intrapedicular Screw. This type of submission focuses on demonstrating substantial equivalence to a predicate device rather than undergoing a new clinical trial to establish safety and efficacy from scratch, especially since the predicate device was preamendment. Therefore, the information requested regarding acceptance criteria and study details for an AI/device performance study (like sample size for test/training sets, expert consensus, MRMC studies) is not applicable to this submission.
Here's a breakdown based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
This section is Not Applicable (N/A) in the context of this 510(k) submission for a traditional medical device, particularly one demonstrating substantial equivalence to a preamendment device. The "acceptance criteria" here relate to meeting the standards of substantial equivalence, which primarily involves demonstrating that the device is as safe and effective as a legally marketed predicate device.
Instead of performance metrics like sensitivity, specificity, etc., the "performance" demonstrated for this device is based on:
| Acceptance Criteria (Demonstrated Equivalence) | Reported Device Performance (Summary of Non-Clinical Tests) |
|---|---|
| Same design as predicate device | "exact same device as the preamendment Townley Bone Graft Screw" |
| Same materials of composition (with addition of MRI-compatible option) | Stainless steel (ASTM F-138) or Ti6Al4V alloy (ASTM F136 or 1472) |
| Same dimensions | Major diameter 3.5 mm, minor diameter 2.70 mm, lengths 25mm to 60mm |
| Same indications for use | "bilateral facet fixation, with or without bone graft, at single or multiple levels, and from C2 to S1" for specified conditions (pseudoarthrosis, spondylolisthesis, spondylolysis, DDD, facet degeneration, fracture) |
| Same method of use | Screws inserted posteriorly through superior side of facet, across facet joint, and into pedicle |
| Conformance to ASTM Standards for Mechanical Testing | Static and fatigue testing conducted in accordance with ASTM Standard F1717 and ASTM Standard E739. |
| Superior mechanical properties for new material | Titanium form has superior ultimate load and higher percentage of ultimate load at run-out in fatigue testing compared to stainless steel. |
2. Sample size used for the test set and the data provenance
N/A. No "test set" in the context of evaluating an AI or software algorithm's performance is described in this document. The evaluation relies on demonstrating equivalence to an existing device through design similarity, material testing, and intended use.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
N/A. No expert consensus or ground truth establishment for a diagnostic or prognostic AI algorithm is discussed.
4. Adjudication method for the test set
N/A. No test set requiring expert adjudication for AI performance is part of this submission.
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
N/A. This is not an AI/software device, and no MRMC comparative effectiveness study was conducted or mentioned. The submission explicitly states "Summary of Clinical Tests (Not applicable.)".
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
N/A. This is a physical spinal implant device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
N/A. For this device, the "ground truth" equivalent would be the established safety and efficacy of the preamendment predicate device and the performance of materials as per ASTM standards.
8. The sample size for the training set
N/A. This is a physical spinal implant device, not an algorithm that requires a training set.
9. How the ground truth for the training set was established
N/A. As above, this is not an algorithm, so there is no training set or ground truth in that context.
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VII. 510(k) Summary
In accordance with the Safe Mcdical Devices Act (SMDA) of 1990 and Title 21 of the Code of Federal Regulations, Part 807), and in particular $807.92, the following summary of information is provided:
Submitted by: A.
R. Stephen Reitzler Vice President, Regulatory Affairs and Quality Assurance NuVasive, Incorporated 10065 Old Grove Road, Suite A San Diego, California 92131 Telephone: (858) 271-7070 Telefacsimile: (858) 271-7101
B. Device Name
| Trade or Proprietary Name: | Townley Transfacet/Intrapedicular Screw |
|---|---|
| Common or Usual Name: | Posterior Facet Screw |
| Classification Name: | Class II |
C. Predicate Devices
The subject device is the exact same device as the preamendment Townley Bone Graft Screw (also known as the Townley Compression Screw), which was marketed prior to May, 1976, by Zimmer Manufacturing Company.
D. Device Description
The Townley Trunfacet/Intrapedicular Screw consists of a broad-headed, partially threaded screw designed to compact juxtaposed facet articular processes to enhance spinal fusion and stability. The non-threaded portion facilitates compression of the joint surfaces through a gliding hole technique. The screws are available fabricated from medical grade stainless steel (ASTM F-138) or Ti6Al4V alloy (ASTM F136 or 1472), and are supplied in various lengths ranging from 25 mm (approx. 0.98") to 60 mm (approx. 2.37"). In all sizes, the screws have a major diameter of 3.5 mm (approx. 0.140") and a minor diameter of 2.70 mm (approx. 0.106").
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E. Intended Use
The Townley Tranfacet/Intrapedicular Screw is intended to stabilize the spine as an aid to fusion through bilateral immobilization of the facet joints. The screws are inserted posteriorly through the superior side of the facet, across the facet joint, and into the pedicle. The Townley Screw is indicated for bilateral facet fixation, with or without bone graft, at single or multiple levels. and from C2 to S1, for treatment of any or all of the following:
- pseudoarthrosis and failed previous fusion: (a)
- spondylolisthesis: (b)
- spondylolysis: (c)
(d) degenerative disc disease (DDD) as defined by neck and/or back pain of discogenic origin as confirmed by radiographic studies;
- degeneration of the facets with instability; and (e)
- (f) fracture
F. Comparison to Predicate Devices
As was established in this submission, the subject device is exactly the same as the preamendment device marketed prior to May of 1976 by the Zimmer Manufacturing Company under the trade names Townley Bone Graft Screw and Townley Compression Screw, excepting only that it will be offered in MRI-compatible titanium alloy in addition to its preamendment stainless steel form.
Affidavits and commercial literature have established that the subject device is the same as the preamendment device in terms of its design, materials of composition, dimensions, indications for use, and method of use, as the preamendment device distributed commercially by Zimmer Manufacturing Company prior to May of 1976. As noted above, only the addition of an MRI-compatible form of the screw is different.
G. Summary of Non-Clinical Tests
Static and fatigue testing conducted in accordance with ASTM Standard F1717 indicate that the titanium form of the subject device has superior ultimate load than the stainless steel form of the device, with a higher percentage of the ultimate load at run-out in the fatigue testing.
H. Summary of Clinical Tests
(Not applicable.)
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I. Conclusions of Non-Clinical and Clinical Tests
As recommended by the agency's Guidance for Spinal System 510(k)s, dated May of 1999, testing has been conducted to demonstrate conformance with ASTM Standard F1717, as applicable to the design of the device, and also with ASTM Standard E739.
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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
APR 1 8 2000
Mr. Steve Reitzler, RAC Vice President. Regulatory Affairs and Quality Assurance Nuvasive Inc. 10065 Old Grove Road. Suite A San Diego, California 92131
Re: K994308/S1
Trade Name: Townley Transfacet/Intrapedicular Screw Regulatory Class: II Product Code: MRW Dated: March 23, 2000 Received: March 24, 2000
Dear Mr. Reitzler:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). You may, therefore, market the device, subject to the general control provisions of the Act. The general control 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 (Premarket Approval), 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 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (OS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
This letter will allow you to begin marketing your device as described in your 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.
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Page 2 - Mr. Steve Reitzler, RAC
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. 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" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or at (301) 443-6597, or at its Internet address "http://www.fda.gov/cdrh/dsmamain.html".
Sincerely vours,
Duna R. Lochner.
Celia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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V. Draft Labeling
Indications for Use A.
510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________
Device Name: NuVasive, Inc., Townley Facet Screw
Indications for Use:
The Townley Tranfacet/Intrapedicular Screw is intended to stabilize the spine as an aid to fusion through bilateral immobilization of the facet joints. The screws are inserted posteriorly through the superior side of the facet, across the facet joint, and into the pedicle. The Townley Screw is indicated for bilateral facet fixation, with or without bone graft, at single or multiple levels, and from C2 to S1, for treatment of any or all of the following:
- pseudoarthrosis and failed previous fusion; (a)
- (b) spondylolisthesis;
- spondylolysis; (c)
- degenerative disc disease (DDD) as defined by neck and/or back pain of (d) discogenic origin as confirmed by radiographic studies;
- degeneration of the facets with instability; and (e)
- () fracture
| Concurrence of CDRH, Office of Device Evaluation (ODE) | Dune K. Lochner (Division Sign-Off) |
|---|---|
| Division of General Restorative Devices | |
| 510(k) Number | K994308 |
| Prescription Use | X |
| (Per 21 CFR 801.109) | |
| OR | |
| Over-The-Counter Use |
N/A