(125 days)
Internal fixation implants are load-sharing devices intended to stabilize and maintain alignment until normal healing occurs. Implants are not intended to replace normal body structures or bear the weight of the body in the presence of incomplete bone healing.
The NAUTILUS Spinal System, when properly used, is intended for posterior pedicle screw fixation of the non-cervical posterior spine in skeletally mature patients. It provides stabilization and immobilization of spinal segments as an adjunct to fusion.
When used as a posterior spine thoracic/lumbar system, the NAUTILUS Spinal System is indicated for one or more of the following: (1) degenerative disc disease (is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), (2) trauma (i.e. fracture or dislocation), (3) curvatures (scoliosis, kyphosis, and/or lordosis), (4) spinal tumor. (5) failed previous fusion (6) pseudoarthrosis, (7) spinal stenosis, (8) spondylolisthesis.
The NAUTILUS Thoracolumbar Spinal System consists of an assortment of rods, screws, cross connectors, and axial and offset connectors. The bone screw, head, and taper lock are assembled together during manufacturing to create the NAUTILUS Thoracolumbar Spinal System screw assembly component. The cross, axial, and offset connectors are also assembled during manufacturing. The NAUTILUS Thoracolumbar Spinal System implant components are made from titanium alloy (Ti-6Al-4V ELI) as described by ASTM F136. Do not use any of the NAUTILUS Thoracolumbar Spinal System components with the components from any other system or manufacturer.
The provided text describes a 510(k) premarket notification for the NAUTILUS Spinal System, asserting its substantial equivalence to predicate devices rather than presenting a performance study with acceptance criteria in the typical sense of a diagnostic or AI device.
Therefore, many of the requested categories (such as sample size for test sets, data provenance, number of experts for ground truth, adjudication methods, MRMC studies, standalone performance, and training set details) are not applicable to this type of submission.
The "acceptance criteria" here are based on demonstrating comparable mechanical performance to existing, legally marketed devices.
Here's a breakdown of the relevant information:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (from Predicate Devices) | Reported Device Performance (NAUTILUS Spinal System) |
|---|---|
| Static Torsion (equivalent performance) | Static Torsion (presented to demonstrate substantial equivalence) |
| Static Compression Bending (equivalent performance) | Static Compression Bending (presented to demonstrate substantial equivalence) |
| Dynamic Compression Bending (equivalent performance) | Dynamic Compression Bending (presented to demonstrate substantial equivalence) |
| Material: Titanium Alloy (Ti-6Al-4V ELI) as per ASTM F136 | Material: 6AL-4V-ELI titanium manufactured according to ASTM F136 |
| Design (substantially equivalent to predicates) | Design (substantially equivalent to predicates) |
| Indications for Use (substantially equivalent to predicates) | Indications for Use (substantially equivalent to predicates) |
| Sizing (substantially equivalent to predicates) | Sizing (substantially equivalent to predicates) |
2. Sample size used for the test set and the data provenance:
- Not Applicable. This is a mechanical performance study based on standardized tests (ASTM F1717) comparing the device to predicate devices, not a clinical study with patient data.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not Applicable. Ground truth in this context refers to the established mechanical properties and performance standards outlined in ASTM F1717, which are not set by human experts in the same way clinical ground truth is.
4. Adjudication method for the test set:
- Not Applicable. The evaluation is based on meeting the specifications of ASTM F1717 and demonstrating equivalence to predicate devices, not on human adjudication of test results.
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. This is not an AI or diagnostic device and therefore no MRMC study was performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not Applicable. This refers to a medical device's mechanical performance, not an algorithm's standalone performance.
7. The type of ground truth used:
- Engineering Standards and Predicate Device Performance. The "ground truth" for this submission is based on established engineering standards (ASTM F1717) and the known performance and characteristics of the predicate devices (K111953, K080767, K061600). The device seeks to demonstrate "substantial equivalence" to these benchmarks.
8. The sample size for the training set:
- Not Applicable. There is no "training set" as this is not an AI/machine learning device. The device's design and manufacturing processes are likely informed by prior engineering knowledge and predicate device designs.
9. How the ground truth for the training set was established:
- Not Applicable. As there is no training set for an AI model, this question is not relevant.
The Study that Proves the Device Meets the Acceptance Criteria:
The study proving the device meets the "acceptance criteria" (i.e., demonstrates substantial equivalence) is the "Performance Data" section described in the 510(k) summary. It states:
- "Static torsion, static compression bending, and dynamic compression bending testing per ASTM F1717 was presented to demonstrate the substantial equivalency of the NAUTILUS Spinal System."
The conclusion further reinforces this:
- "The information presented demonstrates the substantial equivalency of the Nautilus Spinal System."
This indicates that a series of mechanical tests, following the ASTM F1717 standard, were conducted on the NAUTILUS Spinal System. The results of these tests were then compared to the known performance of the predicate devices, and the FDA determined that the NAUTILUS Spinal System's performance was "substantially equivalent" for the stated indications for use.
§ 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.