(152 days)
When used as a pedicle screw fixation system in skeletally mature patients, the Modified VertiFlex® Spinal Screw System is intended to provide immobilization and stabilization of spinal segments as an adjunct to fusion in the treatment of the following acute and chronic instabilities of the thoracic, lumbar, and sacral spine: Degenerative spondylolisthesis with objective evidence of neurological impairment, kyphosis, and failed previous fusion (pseudoarthrosis).
In addition, when used as a pedicle screw fixation system, the Modified VertiFlex® Spinal Screw System is indicated in patients who are receiving fusions with autogenous graft, who are having the device fixed or attached to the lumbar or sacral spine, and who are having the device removed after the development of a solid fusion mass.
The Modified VertiFlex® Spinal Screw System is, like the predicate VertiFlex® Spinal Screw System, a posterior, non-cervical instrumentation system consisting of both pedicle screws and connecting rods. Screws are of polvaxial or monoaxial (fixed) top-loading design, are composed of titanium alloy conforming to ASTM F136-02, and are available in a range of diameters and lengths to accommodate anatomical requirements. Rods are available in rigid or semi-rigid forms, and are composed of titanium conforming to ASTM F67-06, or titanium alloy (Ti 6Al-4V) conforming to ASTM F136-02. Rods are available in both straight and curved styles, and in a range of lengths to accommodate both single-level and multi-level procedures. The Modified VertiFlex® Spinal Screw System may be implanted by either conventional surgical methods, or using minimally-invasive/percutaneous techniques. Manual instrumentation for implantation of the Modified VertiFlex® Spinal Screw System is available for both conventional and minimally-invasive procedures. Screws, rods, and instruments are offered non-sterile, and are intended to be sterilized by the user before use.
This document describes a 510(k) premarket notification for the Modified VertiFlex® Spinal Screw System. It is focused on demonstrating substantial equivalence to existing predicate devices, rather than a clinical study evaluating the device's performance against specific acceptance criteria for a new medical AI device.
Therefore, many of the requested categories for AI device evaluation are not applicable or cannot be extracted from the provided text.
Here is an analysis based on the information provided, highlighting what is available and what is not:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Material Composition | Composed of titanium alloy conforming to ASTM F136-02 (screws) and titanium conforming to ASTM F67-06 or titanium alloy (Ti 6Al-4V) conforming to ASTM F136-02 (rods). |
| Design Characteristics | Designed as a posterior, non-cervical instrumentation system with polyaxial or monoaxial (fixed) top-loading pedicle screws and connecting rods. Available in a range of diameters, lengths, and styles (rigid/semi-rigid rods, straight/curved rods) to accommodate anatomical requirements and surgical methods. |
| Biomechanical Performance | Non-clinical tests, including biomechanical studies and those conducted in accordance with ASTM F1717 (Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model), demonstrated substantial equivalence to commercially-available predicate devices in terms of performance. |
| Indications for Use (as a pedicle screw fixation system) | Intended Use: Immobilization and stabilization of spinal segments as an adjunct to fusion in the treatment of acute and chronic instabilities of the thoracic, lumbar, and sacral spine, specifically: Degenerative spondylolisthesis with objective evidence of neurological impairment, kyphosis, and failed previous fusion (pseudoarthrosis). |
| Additional Indication: Patients receiving fusions with autogenous graft, having the device fixed or attached to the lumbar or sacral spine, and having the device removed after solid fusion mass development. | |
| Sterilization | Offered non-sterile, intended to be sterilized by the user before use. |
2. Sample size used for the test set and the data provenance
- Not Applicable. This is a submission for a spinal implant device, not an AI or diagnostic device that uses a test set of data. The "testing" refers to biomechanical bench testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. See point 2.
4. Adjudication method for the test set
- Not Applicable. See point 2.
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 is not an AI device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not Applicable. This is not an AI device.
7. The type of ground truth used
- For the biomechanical performance, the "ground truth" would be established by the industry standard test methods (e.g., ASTM F1717) which define specific loads, cycles, and failure criteria for spinal implant constructs. The performance of the modified device was compared to predicate devices under these controlled conditions. The "ground truth" for substantial equivalence lies in meeting general device characteristics and performance benchmarks of commercially available predicate devices.
8. The sample size for the training set
- Not Applicable. This is not an AI device.
9. How the ground truth for the training set was established
- Not Applicable. This is not an AI device.
Summary of the Study:
The study proving the device meets its acceptance criteria is primarily a non-clinical biomechanical study and a comparison of design characteristics and materials to legally marketed predicate devices.
- Study Type: Non-clinical (biomechanical studies and material/design comparisons). The document explicitly states: "No clinical testing was conducted to support this submission."
- Purpose: To demonstrate "substantial equivalence" of the Modified VertiFlex® Spinal Screw System to existing, commercially available predicate devices in terms of design, materials, indications, and performance.
- Methodology:
- Material and Design Comparison: The device's materials (titanium alloy, titanium) and design features (posterior, non-cervical, pedicle screws, connecting rods, polyaxial/monoaxial, range of sizes, conventional/minimally-invasive implantation) were compared directly to those of listed predicate devices (e.g., VertiFlex® Spinal Screw System, Isobar® TTL System, Dynesys™ System, N Fix II (N Flex) System, CD HORIZON® System, AccuFlex™ (Protex™) System, ZODIAC® DYNAMO™ System).
- Biomechanical Testing: Non-clinical tests, including those performed in accordance with recognized standards like ASTM F1717 (Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model), were conducted. These tests would simulate physiological loads and assess the mechanical integrity and fatigue life of the implant constructs.
- Acceptance Criteria for Substantial Equivalence: The modified device was deemed substantially equivalent if its design, materials of composition, indications, performance (as demonstrated by biomechanical testing), and other features were comparable to the predicate devices. The specific quantitative acceptance criteria for the biomechanical tests are not detailed in this summary but would be defined within the ASTM F1717 standard and the company's internal testing protocols, ensuring the device performs similarly or superiorly to the predicates.
- Conclusion: The results of the non-clinical tests and comparisons demonstrated the "substantial equivalence" of the Modified VertiFlex® Spinal Screw System to the identified predicate devices, as stated in Section 5.9.
§ 888.3070 Thoracolumbosacral pedicle screw system.
(a)
Identification. (1) Rigid pedicle screw systems are comprised of multiple components, made from a variety of materials that allow the surgeon to build an implant system to fit the patient's anatomical and physiological requirements. Such a spinal implant assembly consists of a combination of screws, longitudinal members (e.g., plates, rods including dual diameter rods, plate/rod combinations), transverse or cross connectors, and interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors).(2) Semi-rigid systems are defined as systems that contain one or more of the following features (including but not limited to): Non-uniform longitudinal elements, or features that allow more motion or flexibility compared to rigid systems.
(b)
Classification. (1) Class II (special controls), when intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra; degenerative spondylolisthesis with objective evidence of neurologic impairment; fracture; dislocation; scoliosis; kyphosis; spinal tumor; and failed previous fusion (pseudarthrosis). These pedicle screw spinal systems must comply with the following special controls:(i) Compliance with material standards;
(ii) Compliance with mechanical testing standards;
(iii) Compliance with biocompatibility standards; and
(iv) Labeling that contains these two statements in addition to other appropriate labeling information:
“Warning: The safety and effectiveness of pedicle screw spinal systems have been established only for spinal conditions with significant mechanical instability or deformity requiring fusion with instrumentation. These conditions are significant mechanical instability or deformity of the thoracic, lumbar, and sacral spine secondary to severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra, degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). The safety and effectiveness of these devices for any other conditions are unknown.”
“Precaution: The implantation of pedicle screw spinal systems should be performed only by experienced spinal surgeons with specific training in the use of this pedicle screw spinal system because this is a technically demanding procedure presenting a risk of serious injury to the patient.”
(2) Class II (special controls), when a rigid pedicle screw system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion in the treatment of degenerative disc disease and spondylolisthesis other than either severe spondylolisthesis (grades 3 and 4) at L5-S1 or degenerative spondylolisthesis with objective evidence of neurologic impairment. These pedicle screw systems must comply with the following special controls:
(i) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(ii) Non-clinical performance testing must demonstrate the mechanical function and durability of the implant.
(iii) Device components must be demonstrated to be biocompatible.
(iv) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(v) Labeling must include the following:
(A) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(B) Intended use and indications for use, including levels of fixation;
(C) Identification of magnetic resonance (MR) compatibility status;
(D) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user; and
(E) Detailed instructions of each surgical step, including device removal.
(3) Class II (special controls), when a semi-rigid system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion for any indication. In addition to complying with the special controls in paragraphs (b)(2)(i) through (v) of this section, these pedicle screw systems must comply with the following special controls:
(i) Demonstration that clinical performance characteristics of the device support the intended use of the product, including assessment of fusion compared to a clinically acceptable fusion rate.
(ii) Semi-rigid systems marketed prior to the effective date of this reclassification must submit an amendment to their previously cleared premarket notification (510(k)) demonstrating compliance with the special controls in paragraphs (b)(2)(i) through (v) and paragraph (b)(3)(i) of this section.