(57 days)
The Zavation Spinal System is a pedicle screw system 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: degenerative spondylolisthesis with objective evidence of neurological impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis).
The Zavation Spinal Systems is also indicated for pedicle screw fixation for the treatment of severe spondylolisthesis (Grades 3 and 4) of the L5-S1 vertebra in skeletally mature patients receiving fusion by autogenous bone graft having implants attached to the lumbar and sacral spine (L3 to sacrum) with removal of the implants after the attainment of a solid fusion.
The Zavation Spinal Systems when used as anterior thoracic/lumbar screw fixation systems, is indicated for degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma (fracture and/or dislocation), spinal stenosis, deformities (scoliosis, lordosis and/or kyphosis), tumor, and previous failed fusion (pseudarthrosis).
The Zavation Spinal System is comprised of polyaxial pedicle screws, rods, and cross connectors. The Zavation Spinal System can be used for single or multiple level fixations. The pedicle screws are available in various lengths and diameters. The rods are available in straight and pre-lordosed (curved) configurations. The system has variable length cross connectors.
The provided document describes the Zavation Spinal System, which is a medical device. The information presented is for the FDA 510(k) clearance process, which focuses on demonstrating substantial equivalence to a predicate device, rather than detailed performance metrics of a novel algorithm or AI system.
Therefore, many of the requested criteria (e.g., sample size for test/training sets, ground truth establishment, MRMC studies, and AI-specific metrics) are not applicable or not provided in this type of regulatory submission. This document describes a traditional mechanical medical device, not an AI/ML-driven device.
Here's an analysis based on the information available:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Mechanical Safety | Performs as well as or better than predicate devices according to ASTM F1717 for static compression bending, torsion, and dynamic compression bending on a worst-case construct. |
| Material | Manufactured from titanium alloy (Ti-6Al-4V) as described by ASTM F136, same as predicate. |
| Design | Rod based fixation system with polyaxial pedicle screws, various screw/rod diameters/lengths, same as predicate. |
| Intended Use | Consistent with predicate devices. |
2. Sample size used for the test set and the data provenance
- Not Applicable. This is a mechanical device, and performance was evaluated through physical mechanical testing, not a clinical test set with patient data.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. Ground truth, in the context of clinical data, is not established for this type of mechanical device testing. Performance is measured against engineering standards (ASTM F1717).
4. Adjudication method for the test set
- Not Applicable. Mechanical testing does not involve adjudication.
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
- No. This is not an AI/ML device, so MRMC studies are not relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No. This is a mechanical device, not an algorithm.
7. The type of ground truth used
- Mechanical Standards and Predicate Performance: The "ground truth" for this device's performance is its ability to meet or exceed the mechanical performance characteristics (e.g., strength, durability under various loads) of its predicate devices, as evaluated through established ASTM standards (specifically ASTM F1717 for static and dynamic mechanical testing).
8. The sample size for the training set
- Not Applicable. This is a mechanical device; there is no "training set" in the context of AI/ML or clinical data used for learning. The "training" in the engineering sense would be the design and manufacturing process, which is not quantified in terms of "sample size" here.
9. How the ground truth for the training set was established
- Not Applicable. As there's no training set, there's no ground truth for it. The ground for mechanical performance is established by engineering principles and ASTM standards.
Summary of the Study:
The study proving the device meets the acceptance criteria is described under the "Performance Data" section. It states:
- Type of Study: Mechanical testing.
- Methodology: Static compression bending and torsion, and dynamic compression bending were performed.
- Standard: The testing was conducted "according to ASTM F1717."
- Construct: A "worst-case construct" was used, implying rigorous testing conditions.
- Results: The mechanical test results "demonstrated that the Zavation Spinal System performs as well as or better than the predicate devices."
This indicates that the acceptance criteria for this mechanical device are defined by its ability to match or surpass the structural integrity and durability of already-cleared predicate devices when tested under standardized, rigorous conditions.
§ 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.