(196 days)
The NFix Fusion System is intended for posterior, noncervical, pedicle fixation in order 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, including degenerative spondylolisthesis with objective evidence of neurologic impairment; fracture; dislocation; scoliosis; spinal tumor; and failed previous fusion (pseudarthrosis).
In addition, when used as a pedicle screw fixation system, the NFix Fusion System is intended for skeletally mature with severe spondylolisthesis (Grades 3 and 4) of the L5-S1 vertebra, who are receiving fusion by autogenous bone graft having implants attached to the lumbar and sacral spine (L3 and below), with removal of the implants after the attainment of solid fusion.
The NFix Fusion System consists of four or more pedicle screws and two NFix solid rods in a symmetric, bilateral arrangement. The pedicle screws are placed axially in the pedicles with two screws in the cephalad position and two screws in the caudad position. The NFix solid rods are secured in the heads of the pedicle screws so that fixed stabilization is provided between the cephalad and caudad vertebrae. Crosslinks can be used if additional stabilization is necessary.
The provided text describes a 510(k) premarket notification for the NFix Fusion System, a spinal implant. However, it does not contain the detailed information necessary to complete a table of acceptance criteria and reported device performance, nor does it describe a study that proves the device meets specific acceptance criteria in the way described in your request.
The document primarily focuses on establishing substantial equivalence to a predicate device (Moss Miami Spinal System) based on similar intended use, design, and mechanical performance characteristics. It provides the following information that relates to your request, but many specific details are missing:
- Device Description: The NFix Fusion System consists of four or more pedicle screws and two solid rods for posterior, noncervical, pedicle fixation.
- Indications for Use: Detailed for acute and chronic instabilities/deformities and severe spondylolisthesis.
- Summary of Testing: States that the technological characteristics are similar to the predicate device due to similarities in intended use, design, and mechanical performance characteristics. This implies that some form of testing was done to demonstrate these similarities, but the specific acceptance criteria and detailed results are not provided in this summary.
Therefore, many parts of your request regarding acceptance criteria, study details, sample sizes, ground truth establishment, and MRMC studies cannot be answered from the provided text.
Here's a breakdown of what can and cannot be addressed:
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Table of acceptance criteria and the reported device performance:
- Cannot be created. The document states "Establishment of similarities is based upon similarities of intended use, design and mechanical performance characteristics." This suggests that the acceptance criteria would be related to meeting certain mechanical performance thresholds comparable to the predicate device, but the specific criteria (e.g., torsion strength, pull-out strength, fatigue life) and the numerical results are not reported here.
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Sample size used for the test set and the data provenance:
- Not provided. The document does not detail any specific test sets, sample sizes, or data provenance. The summary of testing refers to general "technological characteristics" and "mechanical performance characteristics" but not a clinical test set.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable/Not provided. This type of information is usually relevant for studies involving diagnostic or prognostic devices where expert interpretation forms the ground truth. For a spinal implant, ground truth would typically be related to mechanical properties or surgical outcomes, not expert interpretation of outputs. No such expert panel is mentioned.
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Adjudication method for the test set:
- Not applicable/Not provided. Similar to point 3, adjudication methods are usually for interpretive tasks, which are not detailed here for this device.
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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/Not provided. The device is a spinal implant, not an AI-assisted diagnostic tool. Therefore, an MRMC study related to human readers and AI assistance is not relevant to this submission.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable/Not provided. The device is a physical pedicle screw and rod system, not a software algorithm.
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The type of ground truth used:
- Inferred based on device type, but not explicitly stated. For a spinal implant, the "ground truth" for mechanical performance would be established through industry standard mechanical testing (e.g., ISO, ASTM standards) to measure properties like fatigue, static compression, or pull-out strength. For clinical outcomes, it would be patient outcomes data. The document only mentions "mechanical performance characteristics" were assessed for similarity to the predicate.
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The sample size for the training set:
- Not applicable/Not provided. As this is a physical medical device and not a machine learning model, the concept of a "training set" in the context of AI/ML is not applicable.
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How the ground truth for the training set was established:
- Not applicable/Not provided. (See point 8)
In summary, the provided 510(k) summary focuses on demonstrating substantial equivalence through a comparison of design and intended use, and generally mentions "mechanical performance characteristics" without detailing the specific tests, acceptance criteria, or results that would directly answer your questions about study design and performance metrics.
§ 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.