(28 days)
When used as a pedicle screw fixation system in skeletally mature patients, the NGarde 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 lumbar and sacral spine: degenerative spondylolisthesis with objective evidence of neurological impairment and kyphosis.
In addition, when used as a pedicle screw fixation system, the NGarde System is indicated 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 NGarde System is a posterior, non-cervical instrumentation system consisting of both pedicle screws and connecting rods. Screws are of polyaxial top-loading design, are composed of titanium 6Al-4V alloy or titanium 6A1-7Nb, and are available in a range of diameters and lengths to accommodate physiological requirements. The rods are composed of titanium 6A104V alloy and synthetic polycarbonate urethane (PCU) polymer, are 6.0mm in diameter, and are also available in a range of lengths, from 40mm to 200mm.
The modification which is the subject of this Special 510(k) consists of the addition to the NGarde System of two alternate pedicle screws, offered in commercial distribution, which may be used at the physician's discretion as an alternative to the NGarde Systems screws. These alternative pedicle screws are similar and comparable to the NGarde screws and are available in a range of diameters and lengths.
The provided document describes the NGarde System, a pedicle screw system, and its 510(k) summary for a modification. The document explicitly states that no clinical testing was conducted to support this submission. Therefore, it does not contain the detailed information requested regarding device performance, sample sizes, expert involvement, or comparative effectiveness studies.
However, it does provide some information about non-clinical performance and a general statement about acceptance criteria.
Here's the breakdown of what can be extracted based on the provided text:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not explicitly detailed | "met all acceptance criteria." (for verification and validation tests identified through risk analysis for the modification) |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: Not specified. The document only mentions "verification and validation tests."
- Data Provenance: Not specified, as no clinical testing was conducted.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- This information is not applicable as no clinical testing was performed, and thus no "ground truth" was established in a clinical context for a test set. The validation was based on non-clinical performance data.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable as no clinical testing was performed.
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 MRMC study was done. The device is a physical pedicle screw system, not an AI-powered diagnostic or assistive tool for human readers.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not applicable. This is a physical medical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Not applicable for clinical ground truth. For the non-clinical verification and validation, the "ground truth" would be defined by engineering specifications, material properties, and biomechanical standards against which the device performance was measured.
8. The sample size for the training set
- Not applicable as this is a physical medical device, not an AI/ML algorithm requiring a training set.
9. How the ground truth for the training set was established
- Not applicable.
Summary of the Study:
The study referenced for the NGarde System's modification (a Special 510(k)) was primarily a non-clinical performance evaluation. The document states:
- "Non-Clinical Performance and Conclusions: Such verification and validation tests were identified as appropriate to address the results of a risk analysis for the subject Modification were completed, and met all acceptance criteria."
- "Clinical Performance: No clinical testing was conducted to support this submission."
Therefore, the "study" demonstrating that the device meets acceptance criteria was a series of non-clinical verification and validation tests. These tests were designed to address potential risks associated with the modification (addition of two alternate pedicle screws) and ensure that the modified system performed comparably to its predicate devices in terms of mechanical and material properties, as defined by "rigorous design control and risk analysis procedures." The specific acceptance criteria and detailed test results are not provided in this summary but were presumably part of the comprehensive submission to the FDA.
§ 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.