(259 days)
The MEGAFIX(R) Pedicle Screw Spinal System is intended to provide immobilization of spinal segments in skeletally mature patients as an adjunct to fusion using autograft. This system is intended for posterior, non-cervical pedicle fixation of the lumbar and sacral spine for following indications:
Degenerative Disc Disease (DDD) (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies); spondylolisthesis (Grade 1 and 2) of the L5-S1; trauma (i.e., fracture or dislocation); spinal stenosis; curvatures (i.e., scoliosis, and/or lordosis); tumor; pseudoarthrosis; and failed previous fusion.
The MEGAFIX® Pedicle Screw Spinal System is used for posterior, non-cervical pedicle fixation of the lumbar and sacral spine. This system is comprised of monoaxial screws, monoaxial reduction screws, polyaxial screws, polyaxial reduction screws, polyaxial cannulated screws, cannulated reduction screws, straight rods, set screws, and transverse link. All components are supplied non-sterile, single use and made from Titanium Alloy (Ti-6A1-4V ELI) that conforms to ASTM F136. Various types and sizes of these implants are available so that adaptations can be utilized to take into account the unique pathology of individual patients. The MEGAFIX® Pedicle Screw Spinal System is delivered non-sterile and sterilization instructions are provided.
The principle of the spinal fixation is based on pedicle screw-rod locking systems, with the rods transversely crosslinked. A combination of pedicle screws and rods creates a solid "brace" that holds spinal segments. Pedicle screws are fixed through the pedicle bone on the posterior spinal column. The pedicle screw is inserted through the pedicle and into the vertebral body, one on each side. The pedicle screws fix to the bone of the vertebral body, giving them a good solid hold on the vertebrae. Once the pedicle screws are implanted, they are attached to rods that connect all the pedicle screws together. When all components are bolted and tightened by set screws, a stiff metal frame that holds vertebrae still is created so that fusion can occur. Bone graft is then placed around the posterior vertebrae at the implant. A transverse link is used to connect two substantially parallel longitudinal rods for improved stability in the surgical treatment and for increased rotational stiffness for the final construct.
The provided document is a 510(k) summary for the MEGAFIX® Pedicle Screw Spinal System. This document focuses on demonstrating the substantial equivalence of a new medical device to existing predicate devices, primarily through mechanical testing and comparison of technological characteristics.
It does not contain information on acceptance criteria for an AI/algorithm-driven device, nor does it describe a study involving human readers or expert ground truth for image analysis.
However, I can extract the relevant information pertaining to the device's performance testing based on the document's content:
1. A table of acceptance criteria and the reported device performance:
The document states that mechanical testing was performed in accordance with ASTM F1717. The acceptance criteria are implicitly met by stating: "The test results support substantial equivalence of the subject to legally marketed predicate devices." Specific numerical acceptance criteria or performance values are not provided in this summary.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Meet ASTM F1717 standards for medical implants, supporting substantial equivalence to predicate devices for mechanical properties. | "The test results support substantial equivalence of the subject to legally marketed predicate devices." (Specific numerical results are not provided in this summary document.) |
2. Sample size used for the test set and the data provenance:
The document states that "Mechanical testing was performed on the MEGAFIX® Pedicle Screw Spinal System." It falls under pre-market notification (510(k)), implying a laboratory setting for testing the device itself, rather than testing on human subjects or clinical data in the context of device performance. No specific sample sizes for the mechanical tests are given in this summary, nor is there any mention of data provenance in terms of country of origin or retrospective/prospective nature, as this type of information is not relevant to a mechanical component test.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not applicable. The "ground truth" for this device's performance (mechanical strength) is established by engineering standards (ASTM F1717) and direct measurement, not by expert interpretation of data.
4. Adjudication method for the test set:
Not applicable. This is a mechanical device, not an AI or diagnostic tool requiring adjudication of expert interpretations.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
No. This document describes a mechanical medical device, not an AI or imaging-based diagnostic tool. Therefore, an MRMC study is not relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable. This is a physical device, not an algorithm.
7. The type of ground truth used:
The ground truth for the device's mechanical performance is established through adherence to the ASTM F1717 standard for spinal implant constructs, which dictates testing methodologies and performance benchmarks for static and dynamic loading.
8. The sample size for the training set:
Not applicable. There is no "training set" for a mechanical device undergoing physical performance testing.
9. How the ground truth for the training set was established:
Not applicable.
§ 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.