(34 days)
The Ellipse MAGEC Spinal Bracing and Distraction System is intended for skeletally immature patients less than 10 years of age with severe progressive spinal deformities (e.g., Cobb angle of 30 degrees 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 Ellipse Technologies, Inc. MAGEC Spinal Bracing and Distraction System is comprised of a sterile single use spinal rod that can be surgically implanted using appropriate Stryker® Xia fixation components (i.e. Pedicle screws, hooks and/or connectors). The system includes a non-sterile hand held External Remote Controller (ERC) that is used at various times after implant to non-invasively lengthen the implanted spinal rod. The implanted spinal rod is used to brace the spine during growth to minimize the progression of scoliosis. The titanium rod (Ti-6Al-4V ASTM F136) 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. Rotation of the magnet causes the MAGEC rod to be lengthened or shorten.
The hand held non-invasive ERC is electrically powered. The ERC is placed over the patient's spine and then manually activated, which causes the implanted magnet to rotate and either lengthen or shorten the rod. Periodic lengthening of the rod is performed to distract the spine and to provide adequate bracing during growth to minimize the progression of scoliosis. 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 and the MAGEC Wand Magnet Locator. The MAGEC Manual Distractor is a sterilizable, single use device, which is used in the operating room to test the device prior to implantation. 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. The ERC is placed over this location on the child's back.
The provided text describes the MAGEC® Spinal Bracing and Distraction System and its premarket notification (K140178) to the FDA. The submission focuses on establishing substantial equivalence to a predicate device, the Harrington Rod System, rather than providing detailed acceptance criteria and a study proving the device meets those criteria in the context of a diagnostic AI product.
Therefore, much of the requested information (acceptance criteria, specific performance metrics, sample sizes for test/training sets, expert qualifications, adjudication methods, MRMC studies, standalone performance with specific metrics like sensitivity/specificity, and detailed ground truth establishment for training) cannot be extracted from the provided document as it pertains to a mechanical medical device rather than a diagnostic AI.
However, I can extract information related to the device's performance evaluation.
Here's the information that can be extracted and a clear statement about what cannot:
1. A table of acceptance criteria and the reported device performance
The document does not provide a table of numerically defined acceptance criteria for a diagnostic AI product. Instead, it describes performance in terms of mechanical and clinical outcomes for a spinal bracing system.
| Category | Acceptance Criteria (Not explicitly defined as numerical targets for a diagnostic device) | Reported Device Performance |
|---|---|---|
| Non-Clinical Testing | Equivalent mechanical performance to predicate devices (Harrington Rod System). Compliance with relevant mechanical, sterilization, biocompatibility, electrical safety, EMC/EMI, software, and magnetic field safety standards. | - Static and Dynamic Mechanical Testing (ASTM F1717, ASTM F2627): "Results of these tests demonstrate the MAGEC Spinal Bracing and Distraction System can be expected to perform in a manner substantially equivalent to the predicate devices." |
- Shelf Life Packaging Validation (ISO 11607-1): Performed.
- Sterilization (ANSI/AAMI/ISO 11137-2): "Verification that the gamma radiation sterilization process provides a sterility assurance level of 10-6."
- Biocompatibility (ISO 10993-1): Performed.
- Device functionality and verification: Performed.
- Electrical Safety (IEC 60601-1): Performed.
- Electrical Interference and Compatibility (EMC/EMI) (EN 60601-1-2): Performed.
- Magnetic Field Safety (ICNIRP 2009): Performed.
- Software (FDA Guidance (May 11, 2005)): Performed. |
| In Vivo (Animal) Study | Safe and efficient non-invasive distraction of the spine in an animal model. | - Porcine Model (9 male Yucatan pigs): "Results of the in vivo porcine study demonstrates that the MAGEC System is safe and provides an efficient means of non-invasive distraction of the spine. No complications from distraction occurred." Attempted and actual distraction were recorded. |
| Clinical Performance | Safety and probable benefit, including deformity correction, continued growth, and reduced need for subsequent surgical procedures, similar to traditional growing rods. | - Retrospective clinical study (outside US): "The results of the clinical study showed the MAGEC System provides the benefits of spinal deformity correction and continued growth, similar to that for traditional growing rods, without the need for regular surgical lengthening procedures in these children." - Specific endpoints assessed: Cobb angle correction, thoracic spine height increase, improvement in space available for lung (SAL), coronal and sagittal balance, reduction in number of subsequent surgical procedures, and weight gain.
- Demonstrated ability for non-invasive adjustment to lengthen the implanted rod, allowing continued spinal growth and increased Thoracic Spine Height. |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Test Set Sample Size:
- In Vivo (Animal) Study: 9 male Yucatan pigs (randomly assigned to two groups: 1 (MAGEC rod) and 2 (sham)).
- Clinical Study: Not explicitly stated, but described as a "retrospective clinical study for children who had either a primary or revision spinal bracing procedure using the MAGEC System."
- Data Provenance:
- In Vivo Study: Porcine model (animal study).
- Clinical Study: "evaluated outside the United States" (retrospective).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This information is not provided in the document. The studies performed were primarily in vivo animal studies and a retrospective clinical study focusing on device performance and clinical outcomes, not on establishing ground truth for a diagnostic AI.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This information is not provided as it is not relevant to the type of device and studies described.
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
This information is not provided as it is not relevant to the type of device (spinal bracing system) and evaluation presented. It's a study design typically used for diagnostic imaging AI.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This information is not provided as it is not relevant to the type of device described, which is a physical, implantable medical device, not a standalone diagnostic algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Non-Clinical and In Vivo Studies: Ground truth was based on physical measurements, functional specifications, and observation of physiological responses (e.g., distraction achieved, lack of complications) in controlled experimental settings.
- Clinical Performance Data: Ground truth or "probable benefit" was assessed based on clinical outcomes data such as Cobb angle correction, thoracic spine height increase, improvement in space available for lung (SAL), coronal and sagittal balance, reduction in subsequent surgical procedures, and weight gain.
8. The sample size for the training set
This information is not provided as there is no mention of a "training set" in the context of an AI/algorithm-based device. The device is mechanical with non-invasive magnetic actuation.
9. How the ground truth for the training set was established
This information is not provided as there's no training set for an AI in this context.
§ 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.