(242 days)
The LEXUS Cervical Fixation System is indicated for the following:
- DDD (neck pain of discogenic origin with degeneration of the disc as confirmed by patient history and . radiographic studies)
- . Spondylolisthesis
- . Spinal stenosis
- . Fracture/dislocation
- . Failed previous fusion
- . ' Tumors
The implants are intended to provide stabilization as an adjunct to fusion when used with autogenous bone graft or allograft following the reduction of fractures/dislocations or trauma in the spine.
Hooks and rods are also intended to provide stabilization to promote fusion following reduction of fracture/dislocation or trauma in the cervical/upper thoracic (C1 -T3) spine.
The pedicle screws are limited to placement in T1 -T3 in treating thoracic conditions only. The pedicle screws are not intended to be placed in or treat conditions involving the cervical spine.
The LEXUS Cervical Spinal Fixation System is a top-loading, multiple component, posterior (cervical-thoracic) spinal fixation system which consists of polyaxial screws, rods, set screws, and hooks.
Materials: All products are made of titanium alloy (Ti-6Al-4V ELI/ in conformance with ASTM F136) approved for medical use.
The LEXUS Cervical Fixation System's performance was evaluated through mechanical testing according to ASTM F1717 standards, which outlines methods for static and dynamic tests of spinal implant constructs in a vertebral body model.
1. Acceptance Criteria and Reported Device Performance:
| Test Type | Acceptance Criteria (Implied by standard conformance) | Reported Device Performance (Implied by conformance to ASTM F1717) |
|---|---|---|
| Static Axial Compression | Meet specified strength and deformation limits | Conforms to ASTM F1717 |
| Dynamic Axial Compression | Meet specified fatigue life and stability | Conforms to ASTM F1717 |
| Static Tension | Meet specified tensile strength limits | Conforms to ASTM F1717 |
| Static Torsion | Meet specified torsional strength and stiffness limits | Conforms to ASTM F1717 |
Note: The provided document states that the device was "tested according to the ASTM F1717", and that it is "considered substantially equivalent to other legally marketed devices" and "expected to be equivalent in safety and effectiveness." This implies that the device met the performance requirements specified in the ASTM F1717 standard, which serve as the acceptance criteria for mechanical performance for such spinal fixation systems. Specific numerical acceptance criteria and actual reported performance values are not detailed in this summary.
2. Sample Size and Data Provenance for Test Set:
- Sample Size: Not specified in the provided document. As this is mechanical testing, the "sample size" would refer to the number of physical devices or constructs tested for each mechanical test.
- Data Provenance: The testing was conducted by or for L&K BIOMED Co., Ltd., based in the Republic of Korea. The document does not specify the location of the testing laboratory (e.g., in-house, third-party, country). This is a technical performance study, not a clinical study involving human patients.
3. Number of Experts and Qualifications for Ground Truth of Test Set:
- Not applicable. This study focuses on the mechanical performance of the device, not a diagnostic or prognostic assessment requiring expert medical opinion for ground truth.
4. Adjudication Method for Test Set:
- Not applicable. This is a mechanical engineering test, not a clinical study requiring adjudication of expert opinions.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- Not applicable. This is a submission for a physical medical device (spinal fixation system) and its mechanical performance, not an AI or imaging-based diagnostic device. Therefore, no MRMC study was performed.
6. Standalone Performance Study:
- Yes, a standalone study was performed in the sense that the device's mechanical performance was tested independently of its clinical implantation or interaction with human readers. The tests (Static/Dynamic Axial Compression, Static Tension, Static Torsion) evaluated the device itself.
7. Type of Ground Truth Used:
- The "ground truth" for this study is defined by the objective physical and mechanical properties and behaviors of the device as measured against the industry standard (ASTM F1717). This includes parameters like strength, stiffness, and fatigue life under specified loading conditions.
8. Sample Size for Training Set:
- Not applicable. This is not a machine learning or AI device that requires a training set.
9. How Ground Truth for Training Set was Established:
- Not applicable. As this is not a machine learning or AI device, there is no training set and therefore no ground truth establishment for a training set.
§ 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.