(76 days)
The Radius® Spinal System is intended for use in the noncervical spine. When used as an anterior/anterolateral and posterior, noncervical pedicle and non-pedicle fixation system, the Radius Spinal System is intended to provide additional support during fusion using autograft or allograft in skeletally mature patients in 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; trauma (i.e., fracture or dislocation); spinal stenosis; curvatures (i.e., scoliosis, kyphosis, and/or lordosis); tumor; pseudoarthrosis; and failed previous fusion.
The Radius Spinal System can also be linked to the Xia® Titanium Spinal System via the Ø5.5 mm to Ø6.0 mm Radius® rod-to-rod connector.
This 510(k) is intended to introduce an extension to the existing Radius ® Spinal System. The proposed line extension includes the additional screws, rods, and cross connectors.
The provided text describes a Special 510(k) Premarket Notification for a line extension to the Radius Spinal System. It focuses on demonstrating substantial equivalence to predicate devices through mechanical performance testing.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What the device needed to achieve) | Reported Device Performance (What the device actually achieved) |
|---|---|
| Mechanical performance comparable to predicate devices. | The results obtained from Static Compression Bending testing, Static Torsion testing, and Fatigue Compression Bending testing per ASTM F1717 were compared to those of a predicate system to demonstrate substantial equivalence. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size for the mechanical performance tests. It mentions that "tests were conducted" without specifying the number of components or repetitions. The data provenance is described as being generated through in-vitro mechanical testing conducted by the manufacturer, Stryker Spine. It is not patient data, so "country of origin of the data," "retrospective or prospective" are not applicable in this context.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not applicable. The ground truth for this device is based on objective mechanical testing against industry standards (ASTM F1717) and comparison to predicate devices, not expert human assessment.
4. Adjudication Method for the Test Set
Not applicable. As noted above, the assessment is based on objective mechanical testing.
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 device is a mechanical implant, not an AI-assisted diagnostic or therapeutic tool. There is no human reader component to its evaluation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Not applicable. This device is a mechanical implant, not an algorithm. However, the mechanical testing can be considered "standalone" in that it evaluates the device's physical properties independently.
7. The Type of Ground Truth Used
The ground truth used is based on:
- Industry Standard Mechanical Testing: Adherence to ASTM F1717 for Static Compression Bending, Static Torsion, and Fatigue Compression Bending.
- Comparison to Predicate Devices: Performance results were compared to a legally marketed predicate system to demonstrate substantial equivalence.
8. The Sample Size for the Training Set
Not applicable. This device is a mechanical implant and does not involve AI algorithms that require a "training set" in the conventional sense.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
Summary of the Study Proving Device Meets Acceptance Criteria:
The study proving the Radius Spinal System line extension meets its acceptance criteria is a mechanical performance testing study. This study involved:
- Testing Method: Static Compression Bending testing, Static Torsion testing, and Fatigue Compression Bending testing, all conducted according to ASTM F1717.
- Comparison: The results from these tests on the new components of the Radius Spinal System were compared to those of a predicate system.
- Outcome: The comparison demonstrated substantial equivalence in terms of mechanical performance between the new components and the predicate devices. This approach aligns with the recommendations provided in the "Guidance for Industry & FDA Staff Spinal System 510(k)s, May 3, 2004."
The ultimate acceptance criterion for this device, based on the 510(k) process, is demonstrating substantial equivalence to its predicate devices, particularly in terms of material, design, mechanical performance, and indications for use. The mechanical testing described is the mechanism through which this equivalence for performance was established.
§ 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.