(30 days)
The Lanx Spinal Fixation System (SFS) is intended to be used to help provide immobilization and stabilization of spinal segments as an adjunct to fusion of the thoracic, lumbar and/or sacral spine. The System is intended for use with autograft or allograft.
The Lanx Spinal Fixation System is intended for posterior, non-cervical (T1-S2/ilium) pedicle and non-pedicle spinal fixation, to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following instabilities or deformities: degenerative disc disease (DDD, 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; deformities or curvatures (i.e. scoliosis, kyphosis and/or lordosis}; tumor; pseudoarthrosis; and failed previous fusion.
The Lanx Spinous Process Fusion Plate (SPFP) is a posterior, non-pedicle supplemental fixation device, intended for use at a single level in the non-cervical spine (TI-SI). It is intended for plate fixation/attachment to spinous processes for the purpose of achieving supplemental fusion in the following conditions: 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); and/or tumor. The Lanx SPFP is intended for use with bone graft material, not intended for stand-alone use.
The Lanx Spinal Fixation System consists of various screws, hooks, rods, plates, connectors, etc. that are used to build a construct to provide supplemental stabilization of spinal segments to support fusion. The system components can be assembled in a variety of configurations, allowing the surgeon to tailor the construct to the particular needs of the patient. The modifications contained herein consist of a modification to the threadform of the existing pedicle screws as well as a reduced size offset connector and accompanying set screw.
Here's an analysis of the provided text regarding the acceptance criteria and study for the Lanx Spinal Fixation System:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document describes modifications to an existing device, the Lanx Spinal Fixation System, and states that these modifications do not raise new issues of safety or effectiveness. Therefore, the acceptance criteria are not explicitly numerical performance metrics in the way one might see for a diagnostic device. Instead, the acceptance criteria are based on demonstrating comparable mechanical properties and substantial equivalence to the predicate device.
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Mechanical Performance: Components meet established standards for spinal fixation.* | Mechanical testing per ASTM F1717 (static and dynamic axial compression bending and torsion) and ASTM F1798 (axial and torsion); these tests were conducted on the modified components. The system "functioned as intended." |
| Substantial Equivalence to Predicate Device: Modifications do not raise new safety or effectiveness concerns. | The additional components "have the same intended use, indications, technological characteristics and principles of operation as the predicate device." "Engineering analyses also demonstrated comparable mechanical properties to the previously cleared Lanx Spinal Fixation System." |
Note: While specific numerical acceptance values for these mechanical tests are not provided in this summary, they would have been defined within the ASTM standards and the internal study protocols. The summary states the device "functioned as intended" and showed "comparable mechanical properties."
2. Sample Size Used for the Test Set and Data Provenance
This is a mechanical testing study, not a clinical study involving patients or patient data. Therefore, the concept of "test set" in the context of diagnostic AI is not directly applicable here. The "sample size" would refer to the number of individual components tested within the mechanical studies. The document does not specify the exact number of components or samples used for the ASTM F1717 and ASTM F1798 testing.
The "data provenance" is derived from laboratory mechanical testing of the device components. There is no mention of country of origin for data as it's not clinical data, and it's not a retrospective or prospective clinical study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This study involves mechanical testing against engineering standards, not expert-derived ground truth from medical images or clinical observations. The "ground truth" here is the specified performance criteria within the ASTM standards.
4. Adjudication Method for the Test Set
Not applicable. There is no human interpretation or adjudication involved in mechanical testing. The results are quantitative measurements against predefined engineering specifications.
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
Not applicable. This is a mechanical performance study of a spinal fixation system, not an AI-powered diagnostic device. Therefore, no MRMC study with human readers or AI assistance was performed.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This device is a physical medical implant, not an algorithm, so the concept of standalone algorithm performance does not apply.
7. The Type of Ground Truth Used
The ground truth used for this study is based on established engineering standards and specifications. Specifically, the device's mechanical performance was evaluated against the requirements outlined in:
- ASTM F1717: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model.
- ASTM F1798: Standard Guide for Evaluating the Static and Fatigue Performance of Intervertebral Body Fusion Devices Under Combined Compression-Shear Loading.
The "ground truth" is that the device must meet or exceed the performance parameters defined by these standards and demonstrate comparability to the predicate device.
8. The Sample Size for the Training Set
Not applicable. This is a physical device, not a machine learning algorithm. Therefore, there is no "training set."
9. How the Ground Truth for the Training Set Was Established
Not applicable. As there is no training set for an algorithm, there is no ground truth established for it.
§ 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.