(74 days)
When used as a pedicle screw fixation system in skeletally mature patients, the Dynesys Spinal 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 or deformities of the thoracic, lumbar, and sacral spine: degenerative spondylolisthesis with objective evidence of neurologic impairment, and failed previous fusion (pseudoarthrosis).
In addition, when used as a pedicle screw fixation system, the Dynesys Spinal System is indicated for use in patients:
- Who are receiving fusions with autogenous graft only; .
- Who are having the device fixed or attached to the lumbar or sacral spine; .
- Who are having the device removed after the development of a solid fusion mass. .
The Dynesys Spinal System is comprised of a variety pedicle screws sizes, tensioning cords and longitudinal spacers that are uniquely fitted for each individual case. The pedicle screws are manufactured from medical grade titanium alloy. The tensioning cords are manufactured from Sulene-PET (polyethylene-terephthalate). The longitudinal spacers are manufactured from Sulene-PCU (polycarbonate-urethane).
The K043565 510(k) submission for the Dynesys® Spinal System describes the device and its intended use, but it does not include acceptance criteria or a study proving that the device meets such criteria in the context of an AI/ML medical device.
This document pertains to a traditional medical device (spinal fixation system) and its substantial equivalence to a predicate device, rather than an AI/ML-driven diagnostic or treatment system. Therefore, the questions related to AI/ML device performance, such as sample sizes for test and training sets, ground truth establishment, expert qualifications, and MRMC studies, are not applicable to this submission.
The relevant information from the provided text focuses on the comparison of technological characteristics for additional screw components to the existing Dynesys Spinal System, establishing substantial equivalence based on materials, design, and function.
Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Not explicitly stated for AI/ML performance) | Reported Device Performance (Focus on material/design equivalence) |
|---|---|
| N/A (No AI/ML performance criteria specified) | Additional screw components demonstrate no technological differences from current Dynesys Spinal System components. |
| N/A (No AI/ML performance criteria specified) | Substantially equivalent to original Dynesys Spinal System components based on materials, design, and function. |
Answers to Specific Questions (based on the provided text for a non-AI/ML device):
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A table of acceptance criteria and the reported device performance: As shown above, specific performance metrics or acceptance criteria for an AI/ML component are not present. The "performance" described is the finding of substantial equivalence of additional screw components to the predicate device based on material, design, and function.
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Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective): Not applicable. This submission concerns a physical medical device (spinal fixation system), not an AI/ML device requiring a test set of data. The testing mentioned refers to mechanical or physical characteristics of the screw components.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience): Not applicable. No "ground truth" in the context of an AI/ML diagnostic or predictive model is established in this submission. The evaluation is based on engineering and design principles, and comparison to a predicate device.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable. There is no test set in the AI/ML sense to be adjudicated.
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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. No AI component is described, so no MRMC study with AI assistance would have been conducted or reported here.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. There is no algorithm mentioned in this submission.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not applicable. The "ground truth" for this device's substantial equivalence is the existing, legally marketed predicate device, and the engineering principles and standards applied to the new components.
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The sample size for the training set: Not applicable. There is no AI/ML model that would require a training set.
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How the ground truth for the training set was established: Not applicable. No training set is associated with this device submission.
§ 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.