(27 days)
The EQUATION™ Fixation System is a temporary implant system used for correction and stabilization of the posterior spine for the development of a solid spinal fusion. When used as a pedicle screw fixation system of the non-cervical posterior spine in skeletally mature patients, the EQUATION™ Fixation System is indicated for one or more of the following: (1) degenerative spondylolisthesis with objective evidence of neurologic impairment, (2) fracture, (3) dislocation, (4) scoliosis, (5) kyphosis, (6) spinal tumor, and/or (7) failed previous fusion (pseudarthrosis).
In addition, when used as a pedicle screw fixation system, the EQUATION™ Fixation System is indicated for skeletally mature patients: (a) having severe spondylolisthesis (Grades 3 and 4) of the fifth lumbar-first sacral (L5-S1) vertebral joint; (b) who are receiving fusions using autogenous bone graft only; (c) who are having the device fixed or attached to the lumbar and sacral spine (L3 and below); and (d) who are having the device removed after the development of a solid fusion mass.
The Medtronic Sofamor Danek EQUATION™ Fixation System consists of a variety of shapes and sizes of screws, nuts, and rods and cross connectors. The implant components can be rigidly locked in a variety of configurations, with each construct being tailor-made for the individual case. The implants are made of medical grade titanium alloy, and are also offered in medical grade stainless steel. Stainless steel and titanium implant components must not be used together in a construct. The purpose of this submission is to include an additional 3.5mm rod and associated components to the system.
Here's an analysis of the provided text regarding the Medtronic Sofamor Danek EQUATION™ Fixation System, focusing on acceptance criteria and supporting studies:
Assessment of the Provided Information:
The provided document is a 510(k) summary for a medical device (spinal fixation system) seeking clearance for an additional component. Crucially, 510(k) submissions for Class II devices generally do not involve clinical studies with human participants to establish performance against acceptance criteria in the way described in your request. Instead, the primary method for demonstrating safety and effectiveness in such cases is through substantial equivalence to a previously cleared predicate device. This is explicitly stated in the document: "The EQUATION™ Fixation System is substantially equivalent to itself (K013962, SE 06/20/02)." and "Mechanical testing was performed on the subject components. Results indicated that the subject components were substantially equivalent to the previously cleared EQUATION™ Fixation System device."
Therefore, the typical metrics, sample sizes, expert involvement, and statistical analyses relevant to clinical trials (as implied by your questions 1-9) are not applicable or not present in this type of regulatory submission and will not be found herein.
The "acceptance criteria" here relate to the mechanical properties of the new component compared to the previously cleared system, and the "study" is mechanical testing.
Here's a breakdown based on the information available and what can be inferred for a 510(k) for a spinal fixation system:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion (Inferred from 510(k) process) | Reported Device Performance |
|---|---|
| Mechanical Equivalence: The additional 3.5mm rod and associated components must demonstrate mechanical properties (e.g., strength, fatigue life, torsional stiffness, pull-out strength, bending strength) that are substantially equivalent to the corresponding components of the predicate EQUATION™ Fixation System (K013962). | "Results indicated that the subject components were substantially equivalent to the previously cleared EQUATION™ Fixation System device." (Based on mechanical testing.) |
| Risk Profile: The proposed changes (addition of 3.5mm rod) must not introduce any new or increased risks compared to the predicate device. | "A Risk Analysis was performed and determined that the proposed changes do not present any additional risks." |
| Biocompatibility: Materials (medical grade titanium alloy, medical grade stainless steel) must meet established biocompatibility standards for implantable devices. | (Implicit, as the predicate device already uses these materials, and no new materials are introduced. This is not explicitly stated as a new test in this submission but would have been part of the predicate's clearance.) |
| Sterilization: The device must be able to be sterilized to an appropriate Sterility Assurance Level (SAL). | (Implicit, as a standard requirement for implantable devices. Not explicitly stated as a new test for this submission but covered by the predicate's clearance.) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not specified quantitatively in the summary. For mechanical testing of medical devices, "sample size" refers to the number of individual components tested for each specific mechanical property (e.g., 3-6 samples for static tests, 12+ for fatigue tests, per ISO/ASTM standards). This information is typically detailed in the full test report, not the 510(k) summary.
- Data Provenance: The mechanical testing was performed on the "subject components" (the newly added 3.5mm rod and associated components). This would be prospective testing specifically conducted for this 510(k) modification. The country of origin of the data would be the testing laboratories, likely in the USA, given the submitter's location.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Not applicable in the human clinical sense. For mechanical testing, the "ground truth" is established by validated testing methods and engineering standards (e.g., ASTM F1717 for spinal implant constructs, ISO 12189). The "experts" would be the biomedical engineers and technicians performing and interpreting these standardized tests, ensuring they follow protocols to generate reliable data. Their qualifications would be in mechanical engineering, materials science, or related fields, with experience in medical device testing.
4. Adjudication Method for the Test Set
- Not applicable in the clinical sense. For mechanical testing, adjudication would involve standard peer review and verification of test results by other qualified engineers or a quality assurance department to ensure compliance with protocols and accurate reporting. There is no "adjudication method" in the sense of reconciling differing expert opinions on a patient case.
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
- No such study was performed or is relevant. This device is a mechanical spinal implant, not an AI-powered diagnostic or assistive tool for human readers. MRMC studies are for evaluating AI's impact on human interpretation tasks.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- No such study was performed or is relevant. Again, this is a mechanical implant, not an algorithm.
7. The Type of Ground Truth Used
- Established mechanical testing standards and performance specifications. The "ground truth" for the mechanical testing is the expected performance (e.g., ultimate tensile strength, fatigue cycles to failure) as defined by relevant ISO and ASTM standards for spinal implant components, and crucially, the performance of the predicate device's components. The testing aims to demonstrate the newly added components meet or exceed these established benchmarks.
8. The Sample Size for the Training Set
- Not applicable. This device is not an AI algorithm, so there is no training set in the machine learning context.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As there is no training set for an AI algorithm.
In summary: The 510(k) process for this type of device (a modification to an existing mechanical implant) relies on demonstrating substantial equivalence through mechanical testing against established engineering standards and comparison to the predicate device's performance. It does not involve the clinical trial methodologies or AI evaluation metrics described in your comprehensive set of questions.
§ 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.