(84 days)
The Nanovis Spinal System is intended for posterior, non-cervical (i.e., T1-S1) pedicle and non-pedicle fixation to provide immobilization and stabilization in skeletally mature patients as an adjunct to fusion for the treatment of the following acute and chronic instabilities or deformities: degenerative disc disease (DDD, defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, fracture, dislocation, spinal stenosis, scoliosis, kyphosis, lordosis, spinal tumor, pseudarthrosis and failed previous fusion.
The Nanovis Spinal System consists of rods, hooks, monoaxial and polyaxial screws with set screws, and crosslinks with fastening set screws. Rods are available either straight or pre-contoured in a variety of lengths. Hooks are offered in a variety shapes and sizes. Solid and cannulated monoaxial and polyaxial screws are available in standard and reduction versions in a variety of diameter-length combinations to accommodate differing patient anatomy.
The Nanovis Spinal System is a medical device and its approval is based on a demonstration of substantial equivalence to predicate devices rather than the typical performance study structure found in AI/ML device submissions. Therefore, many of the requested categories related to human-AI performance, sample sizes for training/test sets, and ground truth establishment are not applicable.
Here's the information extracted from the provided text regarding the Nanovis Spinal System:
Acceptance Criteria and Device Performance
The acceptance criteria for the Nanovis Spinal System are based on demonstrating mechanical performance that is "as well as or better than the predicate device" through ASTM F1717 testing.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Mechanical performance "as well as or better than" the predicate device for: | "The mechanical test results demonstrated that the Nanovis Spinal System performs as well as or better than the predicate device." |
| - Static compression bending | (Met) |
| - Static torsion | (Met) |
| - Dynamic compression bending of the worst-case construct | (Met) |
Study Proving Device Meets Acceptance Criteria
The study conducted was a mechanical testing study performed according to ASTM F1717.
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Sample size used for the test set and data provenance:
- Sample Size: Not explicitly stated as a number of samples in the classic sense (e.g., cases, images). The testing refers to "the worst case Nanovis construct." This implies that specific configurations of the device were chosen for testing, likely representative samples of the manufactured components.
- Data Provenance: Not applicable in the context of clinical data. This refers to mechanical testing performed on physical prototypes/products.
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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. Mechanical testing uses engineering standards (ASTM F1717) and physical measurements as the 'ground truth,' not expert clinical opinion.
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Adjudication method for the test set:
- Not applicable. Adjudication is relevant for subjective assessments, typically in clinical studies or image review. Mechanical tests yield objective, quantifiable results.
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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:
- No. This is a mechanical device, not an AI/ML diagnostic or assistive tool.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. This refers to a physical medical device (spinal implant system).
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The type of ground truth used:
- The "ground truth" for this device's performance evaluation was established by the specified mechanical testing protocols and acceptance criteria of ASTM F1717. This standard defines the methods for assessing the static and fatigue properties of metallic spinal implant constructs.
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The sample size for the training set:
- Not applicable. This device does not involve a "training set" in the context of AI/ML or statistical modeling.
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How the ground truth for the training set was established:
- Not applicable. As above, there is no "training set" in this context.
§ 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.