(447 days)
The Dyflex-II is a pedicle screw system indicated for the treatment of severe Spondylolisthesis (Grade 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.
In addition, the Dyflex-II is intended to provide immobilization 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, spinal tumor and failed previous fusion (pseudarthrosis).
The Dyflex-II is a non-cervical pedicle screw and rod system intended to facilitate the surgical correction of spinal deformities by providing temporary internal fixation and stabilization during bone graft healing and/or fusion mass development. The Dyflex-II of screws, rods, cross-link connectors, and bolts that can be implanted via percutaneous surgical approach. The components are available in a variety of diameters and lengths in order to accommodate patient anatomy and are fabricated from titanium alloy (ASTM F 136). The implants will be provided non-sterile and the user need to sterilize them before use.
This is a 510(k) premarket notification for the Dyflex-II, a thoracolumbosacral pedicle screw system. The submission aims to demonstrate substantial equivalence to a predicate device, the 4STM Spinal System (K063708).
Here's an analysis of the provided information concerning acceptance criteria and the study:
1. Table of Acceptance Criteria and Reported Device Performance
The device is a pedicle screw system, and its "performance" is primarily assessed through mechanical testing to ensure structural integrity and equivalence to the predicate device.
| Acceptance Criteria Category | Specific Criteria/Standard | Reported Device Performance (Dyflex-II) |
|---|---|---|
| Indications for Use | Same as predicate (4STM Spinal System) | Indication for severe Spondylolisthesis (Grade 3 & 4) of L5-S1 and stabilization for acute/chronic instabilities/deformities of thoracic, lumbar, sacral spine (degenerative Spondylolisthesis, fracture, dislocation, scoliosis, kyphosis, spinal tumor, failed previous fusion). Met. |
| Technological Characteristics | Same as predicate | Described as having the same technological characteristics. Met. |
| Material | Titanium Alloy (ASTM F 136) | Fabricated from titanium alloy (ASTM F 136). Met. |
| Components | Screw, Cross-link Connector, Rod, Bolt | Consists of screws, rods, cross-link connectors, and bolts. Met. |
| Sterilization Validation | In accordance with ISO 17665-1 and ISO 17665-2 | Sterilization validation tests performed. Met. (Implants are provided non-sterile and user sterilizes before use) |
| Mechanical Testing | Performed according to ASTM F 1717, including: |
- Static Torsion Test
- Static Compression Bending Test
- Dynamic Compressive Fatigue Test | Tests performed according to ASTM F 1717 for all listed items. Results supported substantial equivalence despite minor exterior design differences. Met. |
| Screw Size Range (Diameters) | Diameters: 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0mm (Predicate) | Diameters: 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0mm (Dyflex-II) |
| Screw Size Range (Lengths) | Lengths: 30 to 55mm (Predicate) | Lengths: 30 to 50mm (Dyflex-II) |
| Rod Size Range (Diameters) | Diameters: 5.5, 6.0mm (Predicate) | Diameters: 5.5, 6.0mm (Dyflex-II) |
| Rod Size Range (Lengths) | Lengths: 30 to 200mm (Predicate) | Lengths: 30 to 200mm (Dyflex-II) |
Overall Conclusion: The Dyflex-II is deemed substantially equivalent to the predicate device based on similar indications for use, technological characteristics, material, principles of operation, and successful mechanical testing according to industry standards. The size range of the subject device is covered by or very similar to the predicate device.
The document provided is a 510(k) submission for a mechanical medical device (pedicle screw system), not an AI/software as a medical device (SaMD). Therefore, many of the requested items (e.g., test set sample size, provenance, expert ground truth, adjudication, MRMC studies, standalone performance, training set) are not applicable to this type of device submission.
Here's why and what information is pertinent to this submission:
2. Sample size used for the test set and the data provenance:
- Not Applicable. This is a mechanical device. The "test set" refers to physical samples of the device components that undergo mechanical stress testing. The document does not specify the exact number of samples for each mechanical test (e.g., number of screws tested for static torsion). Data provenance is not typically described in terms of geographical origin for mechanical test results; rather, it refers to the conditions and methods under which the tests were conducted.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not Applicable. Mechanical test results for a pedicle screw system do not rely on expert interpretation to establish ground truth in the way medical images or clinical outcomes do. The "ground truth" is determined by objective physical measurements against established engineering standards (ASTM F 1717).
4. Adjudication method for the test set:
- Not Applicable. Since there's no expert interpretation or subjective assessment creating a "ground truth," no adjudication method is needed or described.
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. MRMC studies are relevant for devices involving human interpretation (e.g., radiologists reading images) where AI might assist. This is a mechanical implant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not Applicable. This is not an AI algorithm.
7. The type of ground truth used:
- Engineering Standards / Objective Measurements. For mechanical devices, the "ground truth" is defined by compliance with established engineering standards (e.g., ASTM F 1717) and objective measurements of mechanical properties (e.g., static torsion, compressive fatigue limits).
8. The sample size for the training set:
- Not Applicable. This device does not involve a "training set" in the context of machine learning.
9. How the ground truth for the training set was established:
- Not Applicable. No training set is involved.
§ 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.