(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.
N/A