(51 days)
The MAGEC® System is intended for skeletally immature patients less than 10 years of age with severe progressive spinal deformities (e.g., Cobb andle of 30 dearees or more: thoracic spine height less than 22 cm) associated with or at risk of Thoracic Insufficiency Syndrome (TIS). TIS is defined as the inability of the thorax to support normal respiration or lung growth.
The MAGEC® System is comprised of a sterile single use spinal rod that can be surgically implanted using appropriate NuVasive® Reline®, Reline 4.5-5.0 (Reline Small Stature) or Armada® fixation components (i.e. pedicle screws, hooks and/or connectors). The implanted MAGEC Rod is used to brace the spine during growth to minimize the progression of scoliosis. The system includes a non-sterile hand held External Remote Controller (ERC) 1 or 2 that is used periodically after implantation to non-invasively distract the implanted spinal rod. The titanium MAGEC Rod includes an actuator portion that holds a small internal magnet. The magnet in the actuator can be turned non-invasively by use of the ERC, which is electrically powered. The hand held non-invasive ERC is placed over the patient's spine and then manually activated, which causes the implanted magnet to rotate and either distract or retract the rod. Once the physician determines that the implant has achieved its intended use and is no longer required, the implant is explanted. Additional accessories for the MAGEC® System include the MAGEC Manual Distractor, MAGEC Rod Template, and the MAGEC Wand Magnet Locator. The MAGEC Manual Distractor is a sterile, single use device, which is used in the operating room to test the MAGEC Rod prior to implantation. The MAGEC Rod Template is a sterile, single-use accessory used for intraoperative planning of the surgical procedure. The MAGEC Wand Magnet Locator is a non-sterile device which is used during the distraction procedure to locate the magnet within the MAGEC Rod previously implanted in a patient.
The purpose of this premarket notification is to implement assembly process changes and a design change to the MAGEC Rod cleared in K171791 to address the Field Safety Notice and Product Recall issued on February 13, 2020 for the MAGEC X device (FDA Recall Number Z-1898-2020 and Recall Event ID 85495).
The provided text is a 510(k) summary for the NuVasive MAGEC® System, which is a spinal rod system designed for skeletally immature patients with severe progressive spinal deformities. The submission aims to demonstrate substantial equivalence to previously cleared MAGEC systems.
Here's an analysis of the acceptance criteria and study information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative "acceptance criteria" for device performance in terms of specific thresholds for outcomes (e.g., minimum distraction force, maximum bending, etc.) that the device needed to meet. Instead, it refers to performance testing against established ASTM standards and internal verification for distraction/retraction. The general "acceptance criteria" can be inferred as demonstrating substantial equivalence to the predicate devices through successful completion of the listed nonclinical tests.
| Test Description | Applicable Standard | Reported Device Performance |
|---|---|---|
| Static Compression Bending | ASTM F1717: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model | Demonstrated substantial equivalence to predicate devices |
| Dynamic Compression Bending | ASTM F1717: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model | Demonstrated substantial equivalence to predicate devices |
| Static Torsion | ASTM F1717: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model | Demonstrated substantial equivalence to predicate devices |
| Distraction and Retraction Verification | N/A | Demonstrated substantial equivalence to predicate devices (verified function) |
| Torsional Strength | ASTM F1798: Standard Guide For Evaluating The Static And Fatigue Properties Of Interconnection Mechanisms And Subassemblies Used In Spinal Arthrodesis Implants | Demonstrated substantial equivalence to predicate devices |
2. Sample Size Used for the Test Set and Data Provenance
The document only mentions "nonclinical testing" and lists standards for mechanical testing. It does not provide details on the sample size for these tests (e.g., number of rods tested for bending, torsion, etc.). The data provenance is also not specified beyond being "nonclinical testing." It does not involve human data, so terms like "country of origin" or "retrospective/prospective" are not applicable in this context.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This information is not applicable. The testing described is nonclinical mechanical testing, not clinical studies requiring expert review or ground truth establishment in a diagnostic context.
4. Adjudication Method (e.g., 2+1, 3+1, none) for the Test Set
This information is not applicable as the testing is nonclinical mechanical testing and does not involve human assessment or adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, an MRMC comparative effectiveness study was not done. The submission focuses on nonclinical testing for substantial equivalence of a medical device (spinal rod system), not on diagnostic performance or human reader improvement with AI assistance.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
This question is not applicable. The MAGEC System is a physical medical device (spinal rod and external controller), not an algorithm or AI system. Its performance is related to mechanical properties and functional reliability, not algorithmic accuracy.
7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)
The "ground truth" for the nonclinical tests is established by the specifications and acceptance limits defined within the referenced ASTM standards (e.g., specific forces, deflections, cycles, or distraction distances). The device is expected to meet or exceed the performance of the predicate and comply with these mechanical standards.
8. The Sample Size for the Training Set
This information is not applicable. The MAGEC System is a physical device, not an AI/ML model that requires a training set.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable, as there is no training set for a physical medical device.
§ 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.