(5 days)
Synthes Craniofacial Screws are intended for selective trauma of the midface and craniofacial skeleton; craniofacial surgery; reconstructive procedures; and selective orthognathic surgery of the maxilla and chin.
Synthes Craniofacial screws are available with either selftapping or self-tapping/self-drilling tips. They are offered in 1.3 mm standard diameter and are also available in a 1.7 mm Emergency diameter. The self-drilling 1.3 mm diameter screws are offered in two variations: cortex and cranial, with the cranial having a slightly greater core diameter and a modified thread profile. The self-drilling screws are offered in 3 -- 6 mm lengths and the self-tapping screws are offered in 3 - 18 mm lengths. The modified Synthes craniofacial screws are available in four variants: 1) 1.3 mm craniofacial self-tapping (3-18 mm lengths), 2) 1.3 mm craniofacial self-drilling (3-6 mm lengths), 3) 1.3 mm cranial self-drilling (3-5 mm lengths), 4) 1.7 mm emergency self-tapping screws (3-18 mm lengths). The new cranial screws have a slightly greater core diameter and a modified thread profile. All the new/ modified screws feature the StarDrive™ drive mechanism and are now made from titanium alloy. The new/modified 1.3 mm self-drilling screws have slightly larger core diameters than the design previously cleared: 0.95 mm (craniofacial) & 1.01 mm (cranial) versus 0.85 mm. The 1.3 mm craniofacial self-drilling screw is also being offered in a 3mm length. The 1.3 mm cranial selfdrilling screw also has a slightly modified thread profile to lower stress concentrations and increase torsional strength. The self-tapping screws are being offered in titanium alloy (TAN) and feature the StarDrive™ drive mechanism while the previously cleared self-tapping screws were manufactured from commercially pure (CP) titanium and utilized a cruciform drive mechanism.
The provided text describes the acceptance criteria and the study conducted for the "Synthes 1.3 mm Craniofacial Screws" device.
1. Table of Acceptance Criteria and Reported Device Performance:
| Concern | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Insertion torque | Insertion torque of modified screw design to be equal to or less than predicate. | PASS – Modified screw requires approximately 3.5% less insertion torque. |
| Maximum torque | Maximum torque for the modified screw design to be equal to or greater than the predicate. | PASS – Modified screw showed a 67% increase in torsional strength compared to predicate. |
2. Sample Size Used for the Test Set and Data Provenance:
The document refers to "verification testing" and "results of verification testing" being presented, but does not explicitly state the sample size used for these tests. The tests are mechanical and material property tests (e.g., driving torque, torsional properties), inherently indicating a prospective study design where new screws were manufactured and tested. The data provenance is US-based, as the device manufacturer is Synthes (USA) and the submission is to the U.S. Food and Drug Administration (FDA).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
This information is not applicable as the study described is for mechanical and material performance of a physical device, not related to medical imaging or diagnostics that would require expert-established ground truth. The "ground truth" here is defined by physical measurements against predefined engineering standards.
4. Adjudication Method for the Test Set:
This information is not applicable for this type of mechanical testing. Adjudication methods like 2+1 or 3+1 are typically used in clinical studies or image interpretation where human judgment is involved in establishing a ground truth.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
This information is not applicable. An MRMC study is relevant for diagnostic devices (e.g., AI in radiology) where the performance of human readers with and without AI assistance is compared. The device in question is a cranial screw, a mechanical implant.
6. Standalone (i.e., algorithm only without human-in-the-loop performance) Study:
This information is not applicable. Standalone performance is a concept for algorithmic or AI-based devices. The study here focuses on the mechanical properties of a physical screw.
7. Type of Ground Truth Used:
The ground truth used in this study is based on pre-defined engineering specifications and direct physical measurements of the device's mechanical properties (insertion torque and maximum torque). These measurements are then compared to the performance of a previously cleared predicate device.
8. Sample Size for the Training Set:
This information is not applicable. The study is not an AI/machine learning study that would involve a "training set." It is a mechanical performance study of a physical medical device.
9. How the Ground Truth for the Training Set Was Established:
This information is not applicable as there is no training set involved in this mechanical performance study.
§ 872.4880 Intraosseous fixation screw or wire.
(a)
Identification. An intraosseous fixation screw or wire is a metal device intended to be inserted into fractured jaw bone segments to prevent their movement.(b)
Classification. Class II.