FDA 510(k) Search - By Innolitics (SaMD and AI Experts)

The Rexious Spinal Fixation System is intended to provide immobilization 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: degenerative disc disease; spondylolisthesis; fracture; dislocation; scoliosis; kyphosis; spinal tumor; and failed previous fusion (pseudarthrosis).

Device Description

The Rexious Spinal Fixation System is a top-loading multiple component, posterior spinal fixation system which consists fixation system which consists of pedicle screws, rods, set screws, connectors, and transverse (cross) linking mechanisms.

The Rexious Spinal Fixation System will allow surgeons to build a spinal implant construct to stabilize and promote spinal fusion. The Rexious implant components are supplied non-sterile, single use and fabricated from titanium or titanium alloy (Ti-6Al-4V ELI) as specified in ASTM F67, F136, and F1295 and from Cobalt-Chromium-Molybdenum (CoCr) as specified in ASTM F1537. Various sizes of these implants are available.

AI/ML Overview

This document describes a spinal fixation system, not an AI device. As such, the typical acceptance criteria and study designs relevant to AI (like sensitivity, specificity, MRMC studies, ground truth establishment by experts, etc.) are not applicable here.

Instead, the document details the Rexious Spinal Fixation System, a medical device subject to FDA 510(k) clearance. The "acceptance criteria" for such a device are primarily demonstrated through substantial equivalence to a predicate device, supported by performance testing and engineering analysis.

Here's an interpretation of the request in the context of this device:

1. A table of acceptance criteria and the reported device performance:

Acceptance Criteria (Demonstrated through Substantial Equivalence and Testing)	Reported Device Performance (Summary from 510(k))
Material Properties: Conformity to ASTM standards for implant materials.	Components fabricated from titanium or titanium alloy (Ti-6Al-4V ELI) as specified in ASTM F67, F136, and F1295, and from Cobalt-Chromium-Molybdenum (CoCr) as specified in ASTM F1537.
Biocompatibility: Materials are suitable for implantation.	Implied by conformity to specified ASTM standards for implant materials, which inherently include biocompatibility considerations for long-term implantation.
Mechanical Performance (Static & Dynamic): Ability to withstand physiological loads without failure.	Static and Dynamic compression bend tests performed per ASTM F1717. The addition of new components (lengths of rods, new material for rods, additional screw sizes, and transverse connector sizes) did not introduce a new worst-case construct as evaluated based on an engineering analysis, indicating performance is maintained within acceptable limits compared to the predicate.
Design Characteristics:	Top-loading multiple component, posterior spinal fixation system consisting of pedicle screws, rods, set screws, connectors, and transverse (cross) linking mechanisms. Various sizes available. The modified system has the same fundamental scientific technology as the previously cleared system.
Intended Use: Device performs its specified function in treating spinal instabilities/deformities as an adjunct to fusion.	Intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of: degenerative disc disease, spondylolisthesis, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). This is consistent with the predicate device.
Sterilization: Supplied non-sterile, single-use.	Components are supplied non-sterile, single use. Sterilization procedures, if required prior to use, would be performed by the end-user facility as per standard medical practice and the device's IFU (not detailed here, but a general requirement for non-sterile devices).

2. Sample size used for the test set and the data provenance:

Sample Size: The document does not specify a "sample size" in the context of clinical data for a "test set" as one would for an AI algorithm. Instead, it refers to the addition of components and various sizes of these implants. The testing (ASTM F1717) would have been performed on a statistically relevant number of samples of each component or construct configuration to demonstrate mechanical properties. The exact number of samples for each test (e.g., how many rods of each length, how many screws of each size) is not explicitly stated in this summary.
Data Provenance: Not applicable in the context of clinical data as no clinical study is described for this 510(k) submission. The data provenance refers to material testing and engineering analysis.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

Not applicable. This device's clearance is based on mechanical performance testing and substantial equivalence, not on expert-adjudicated clinical "ground truth" data sets like an AI model would require.

4. Adjudication method for the test set:

Not applicable. There is no human adjudication of a "test set" in the context of this device. Mechanical tests have objective pass/fail criteria based on standards (e.g., ASTM F1717).

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:

No, an MRMC study was not done. This type of study is relevant for diagnostic devices where human reader performance is being evaluated, often with or without AI assistance. This is a spinal fixation system, not a diagnostic imaging or AI device.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Not applicable. This is not an algorithm or AI device.

7. The type of ground truth used:

For a spinal fixation system, the "ground truth" for performance is typically established by:
- Material specifications: Adherence to recognized ASTM standards for implant materials (e.g., ASTM F67, F136, F1295, F1537).
- Mechanical test standards: Performance meeting the requirements of established international standards for spinal implants (e.g., ASTM F1717 for static and dynamic compression bending). These standards define the expected mechanical behavior and failure modes.
- Engineering analysis: Demonstrating that design changes (like new rod lengths or materials) do not introduce new "worst-case" scenarios or negatively impact performance compared to the predicate.

8. The sample size for the training set:

Not applicable. This is a medical device (hardware), not an AI algorithm, so there is no "training set."

9. How the ground truth for the training set was established:

Not applicable. As above, there is no "training set" for this type of device.

Summary

Regulation Number and Section

§ 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.