(23 days)
The Invictus® Small Stature Spinal Fixation System is intended for non-cervical posterior and anterolateral fixation in skeletally mature patients as an adjunct to the following indications: degenerative disc disease (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies); spondylolisthesis; trauma (i.e., fracture or dislocation); spinal stenosis; curvatures (i.e., scoliosis, kyphosis and/or lordosis); tumor; pseudarthrosis; and/or failed previous fusion.
When used for posterior non-cervical screw fixation in pediatric patients, the Invictus® Small Fixation System implants are indicated as an adjunct to fusion to treat progressive spinal deformities (i.e., scoliosis, or lordosis) including idiopathic scoliosis, neuromuscular scoliosis, and congenital scoliosis. Additionally, the Invictus® Small Stature Spinal Fixation System is intended to treat pediatric patients diagnosed with the following conditions: spondylolisthesis / spondylolysis, fracture caused by tumor and/or trauma, pseudarthrosis, and/or failed previous fusion. Pediatric pedicle screw fixation is limited to a posterior approach.
The Invictus® Small Stature Spinal Fixation System is intended to be used with autograft and/or allograft.
The Invictus® Small Stature Spinal Fixation System is intended to help provide immobilization and stabilization of spinal segments as an adjunct to fusion of the thoracic, lumbar, and/or sacral spine. The Invictus® Small Stature Spinal Fixation system is compatible with Arsenal® Spinal Fixation System and Invictus® Spinal Fixation System offered by Alphatec Spine using various rod-to-rod connectors and/or transitional rods. The Invictus® Small Stature Spinal Fixation System consists of a variety of shapes and sizes of rods, screws, hooks, connectors, and cross connectors that provide internal fixation and stabilization during bone graft healing and/or fusion mass development. The screws, hooks, connectors, and cross connectors are manufactured from surgical grade titanium alloy (Ti-6Al-4V ELI) per ASTM F136. The rods are available in commercially pure titanium (CP Ti Grade 4) per ASTM F67, titanium alloy (Ti-6A1-4V ELI) per ASTM F136, and cobalt chrome (Co-28Cr-6Mo) per ASTM F1537.
The Invictus® Small Stature implants are provided non-sterile to be steam sterilized by the end user. The instruments are made of stainless steel and other materials and are provided non-sterile to be cleaned and sterilized by the end user. The instruments in this system are intended for use in surgical procedures.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided FDA 510(k) summary for the Invictus® Small Stature Spinal Fixation System:
Summary of Device and Context:
The Invictus® Small Stature Spinal Fixation System is a medical device intended for non-cervical posterior and anterolateral fixation in skeletally mature patients and pediatric patients with certain spinal conditions, as an adjunct to fusion. It consists of various components like rods, screws, and connectors, made from surgical grade titanium alloy, commercially pure titanium, and cobalt chrome.
The document is an FDA 510(k) clearance letter, meaning the manufacturer, Alphatec Spine, Inc., is seeking to demonstrate that their new device is "substantially equivalent" to already legally marketed predicate devices, rather than requiring a full Premarket Approval (PMA) application. This typically means the focus of the performance data is on showing comparable safety and effectiveness, often through non-clinical (mechanical) testing, rather than extensive clinical trials with human subjects.
Acceptance Criteria and Device Performance
The provided document does not detail specific numerical acceptance criteria for a study involving AI or software. Instead, it focuses on the substantial equivalence of a physical medical device (spinal fixation system) through non-clinical (mechanical) testing.
Therefore, the "acceptance criteria" here are implied to be the successful demonstration that the Invictus® Small Stature Spinal Fixation System performs comparably to its predicate devices in various mechanical tests, within established industry standards. The reported device performance is that it met these standards.
Table of Acceptance Criteria and Reported Device Performance (as inferred):
| Acceptance Criteria Category (Implied) | Specific Test (from document) | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|---|
| Mechanical Strength & Durability | ASTM F1717 Static Compression Bending | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
| Mechanical Strength & Durability | ASTM F1717 Dynamic Compression Bending | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
| Mechanical Strength & Durability | ASTM F1798 Static A-P Tulip Pull-off (Fx) Straight | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
| Mechanical Strength & Durability | ASTM F1798 Static A-P Tulip Pull-off (Fx) – Angled | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
| Mechanical Strength & Durability | F1798 Static Flexion-Extension (My) Bottom-loading, Straight | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
| Mechanical Strength & Durability | F1798 Static Flexion-Extension (My) Bottom-loading, Angled | Must meet or exceed predicate device performance and relevant ASTM standards for spinal implants. | Results demonstrate substantial equivalence to predicate devices. |
The study described is a non-clinical, mechanical performance study, not a clinical study involving human patients or an AI/software assessment. As such, many of the typical questions for AI/software evaluations (sample size for test/training sets, experts for ground truth, MRMC studies, standalone performance of an algorithm) do not apply to this specific document.
Information Not Applicable / Not Provided in the Document:
Given this is a physical device clearance (spinal fixation system) based on substantial equivalence through non-clinical testing, the following points are not applicable (N/A) or not detailed in this 510(k) summary:
- Sample sizes used for the test set and data provenance (e.g., country of origin of the data, retrospective or prospective): N/A, as this refers to mechanical testing, not a data-driven clinical or AI study. The "test set" would be the physical prototypes or samples of the device tested in a lab. The "data provenance" would relate to the manufacturing location and testing lab.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: N/A. Mechanical testing relies on standardized ASTM methods, not expert interpretation of outputs or images.
- Adjudication method (e.g., 2+1, 3+1, none) for the test set: N/A. Not relevant for mechanical testing.
- 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: N/A. This is a study design for evaluating software/AI in a clinical context, which is not what this 510(k) addresses.
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: N/A. There is no algorithm mentioned in the context of this device.
- The type of ground truth used (expert consensus, pathology, outcomes data, etc): N/A. Ground truth for mechanical testing is derived from the physical properties and performance measured by the specified ASTM standards.
- The sample size for the training set: N/A. There is no AI/software component, hence no training set.
- How the ground truth for the training set was established: N/A. No training set for AI/software.
In conclusion: The provided FDA 510(k) document pertains to the clearance of a physical medical device (spinal fixation system) based on a demonstration of substantial equivalence to predicate devices through non-clinical (mechanical) performance data, as per ASTM standards. It does not involve AI, software, or clinical efficacy studies as would be the case for new diagnostic or interpretation tools.
§ 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.