(249 days)
The Signature Orthopaedics Freedom Cervical Screw and Rod System is intended to provide immobilization and stabilization of spinal segments in skeletally mature patients (C1 to C7) as an adjunct to fusion in the treatment of the following acute and chronic instabilities and deformities of the cervical spine:
- traumatic spinal fractures and/or traumatic dislocations
- instability or deformity; failed previous fusions (e.g. pseudarthrosis)
- degenerative disease, including neck and/or arm pain of discogenic origin as confirmed by radiographic studies, and degenerative disease of the facets with instability, and
- short term stabilization of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom expectancy is of insufficient duration to permit achievement of fusion.
The Freedom™ Posterior Cervical Screw System consists of screws, longitudinal rods and cross connectors in a variety of sizes to accommodate differing anatomic requirements. The cervical screws are inserted into adjacent vertebrae, then rods are clamped into the tulip of the pedicle screw using the cap screw, thus immobilising the instrumented vertebrae. The cross-connector may then be attached between rods to improve stability. The system components are made of Ti6Al4V alloy and are supplied sterile.
The provided FDA 510(k) clearance letter pertains to the Freedom Posterior Cervical Screws, which is a medical device and not an AI/ML-driven software system. As such, the information you've requested regarding acceptance criteria, study details, sample sizes, ground truth, and human reader performance is not applicable to this type of device submission.
The FDA clearance for this device is based on demonstrating substantial equivalence to a legally marketed predicate device, primarily through non-clinical performance testing and engineering evaluations. These tests focus on the physical and mechanical properties of the screws to ensure they are safe and effective for their intended use as a spinal implant.
Here's a breakdown of the relevant information provided in the document concerning the device's performance:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Tests Performed | Reported Device Performance |
|---|---|---|
| Mechanical Strength & Durability | Static and dynamic compression bending testing | Results demonstrated that the strength of the system is sufficient for its intended use. |
| Static torsion testing | Results demonstrated that the strength of the system is sufficient for its intended use. | |
| Static Flexion-Extension Moment Test | Results demonstrated that the strength of the system is sufficient for its intended use. | |
| Axial Gripping Test | Results demonstrated that the strength of the system is sufficient for its intended use. | |
| Axial Torsional Test | Results demonstrated that the strength of the system is sufficient for its intended use. | |
| Surgical Handling & Integration | Screw insertion testing | Not explicitly detailed performance, but implies successful insertion. |
| Screw pull-out testing | Not explicitly detailed performance, but implies adequate resistance to pull-out. | |
| Screw torque to failure testing | Not explicitly detailed performance, but implies appropriate torque resistance. | |
| Compliance with Standards | Adherence to ASTM-F1717 (Spinal Implant Construct in a Vertebrectomy Model) | Confirmed compliance with relevant standards. |
| Adherence to ASTM-F1798 (Static and Fatigue Properties of Interconnection Mechanisms and Subassemblies Used in Spinal Arthrodesis Implants) | Confirmed compliance with relevant standards. | |
| Adherence to ASTM-F543 (Metallic Medical Bone Screw) | Confirmed compliance with relevant standards. | |
| Substantial Equivalence | Comparison with Predicate Device (Saxxony™ Posterior Cervical Thoracic System - K182508) | Demonstrated "nearly identical technological characteristics" and that "minor differences do not raise any new issues of safety and effectiveness." |
2. Sample size used for the test set and the data provenance:
- The document states that "worst-case sizes of the subject cervical screws" were tested.
- Sample size: Not explicitly quantified with a specific number of units, but implied it was a representative selection of "worst-case sizes."
- Data provenance: The tests were "non-clinical testing and engineering evaluations" conducted by the manufacturer, Signature Orthopaedics Pty Ltd, in Australia. This is a form of prospective testing done specifically for regulatory submission.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This is a hardware device where "ground truth" is established through engineering principles and physical testing against established ASTM standards, not through expert human interpretation or diagnosis.
4. Adjudication method for the test set:
- Not applicable. This involves objective mechanical testing, where results are measured directly against predefined acceptance criteria from engineering standards. There is no subjective adjudication process for establishing a "ground truth" as would be the case for image interpretation or diagnostic performance.
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 surgical implant, not an AI-assisted diagnostic tool. Therefore, no MRMC studies or human reader performance evaluations were conducted or are relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is a physical product, not a software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The "ground truth" for this device's performance is derived from established mechanical and material engineering standards (ASTM standards). The device's components must meet or exceed the performance specifications (e.g., strength, fatigue resistance) outlined in these standards to be deemed safe and effective for their intended surgical purpose.
8. The sample size for the training set:
- Not applicable. This refers to a dataset used to train an AI model. This device is hardware and does not involve a training set.
9. How the ground truth for the training set was established:
- Not applicable. As above, there is no training set for this type of medical device submission.
§ 888.3075 Posterior cervical screw system.
(a)
Identification. Posterior cervical screw systems are comprised of multiple, interconnecting components, made from a variety of materials that allow an implant system to be built from the occiput to the upper thoracic spine to fit the patient's anatomical and physiological requirements, as determined by preoperative cross-sectional imaging. Such a spinal assembly consists of a combination of bone anchors via screws (i.e., occipital screws, cervical lateral mass screws, cervical pedicle screws, C2 pars screws, C2 translaminar screws, C2 transarticular screws), longitudinal members (e.g., plates, rods, including dual diameter rods, plate/rod combinations), transverse or cross connectors, interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors), and closure mechanisms (e.g., set screws, nuts). Posterior cervical screw systems are rigidly fixed devices that do not contain dynamic features, including but not limited to: non-uniform longitudinal elements or features that allow more motion or flexibility compared to rigid systems.Posterior cervical screw systems are intended to provide immobilization and stabilization of spinal segments in patients as an adjunct to fusion for acute and chronic instabilities of the cervical spine and/or craniocervical junction and/or cervicothoracic junction such as: (1) Traumatic spinal fractures and/or traumatic dislocations; (2) deformities; (3) instabilities; (4) failed previous fusions (
e.g., pseudarthrosis); (5) tumors; (6) inflammatory disorders; (7) spinal degeneration, including neck and/or arm pain of discogenic origin as confirmed by imaging studies (radiographs, CT, MRI); (8) degeneration of the facets with instability; and (9) reconstruction following decompression to treat radiculopathy and/or myelopathy. These systems are also intended to restore the integrity of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom life expectancy is of insufficient duration to permit achievement of fusion.(b)
Classification. Class II (special controls). The special controls for posterior cervical screw systems are:(1) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(2) Nonclinical performance testing must demonstrate the mechanical function and durability of the implant.
(3) Device components must be demonstrated to be biocompatible.
(4) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(5) Labeling must include the following:
(i) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(ii) Intended use and indications for use including levels of fixation;
(iii) Device specific warnings, precautions, and contraindications that include the following statements:
(A) “Precaution: Preoperative planning prior to implantation of posterior cervical screw systems should include review of cross-sectional imaging studies (
e.g., CT and/or MRI) to evaluate the patient's cervical anatomy including the transverse foramen, neurologic structures, and the course of the vertebral arteries. If any findings would compromise the placement of these screws, other surgical methods should be considered. In addition, use of intraoperative imaging should be considered to guide and/or verify device placement, as necessary.”(B) “Precaution: Use of posterior cervical pedicle screw fixation at the C3 through C6 spinal levels requires careful consideration and planning beyond that required for lateral mass screws placed at these spinal levels, given the proximity of the vertebral arteries and neurologic structures in relation to the cervical pedicles at these levels.”
(iv) Identification of magnetic resonance (MR) compatibility status;
(v) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user, and;
(vi) Detailed instructions of each surgical step, including device removal.