(115 days)
The Dali Spinal Fixation System is non-cervical spinal fixation devices intended for use as posterior pedicle fixation systems (T1-S2/ilium), or as an anterolateral fixation system (T8-L5). All components in the system are limited to skeletally mature patients. System components are to be used for immobilization and stabilization of the spine as an adjunct to fusion. These devices are indicated for all of the following indications regardless of the intended use:
- degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies);
- spondylolisthesis;
- trauma (i.e. fracture or dislocation);
- deformities or curvatures (i.e., scoliosis, kyphosis, and/or lordosis);
- tumor;
- stenosis, and;
- failed previous fusion (pseudoarthrosis)
This system is comprised of screws, set screws, rods, crosslink and connectors. The components of this system are manufactured of Titanium alloy (Titanium-6Aluminum-4Vanadium ELI, per ASTM F136) and CoCrMo alloy (Cobalt-28Chromium-6Molybdenum, per ASTM F1537). The screws are available from 4.0 to 8.5mm diameters with lengths ranging from 20-150mm.
The provided text describes the "Dali Spinal Fixation System," a Class III medical device for spinal fixation. Here's a breakdown of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Mechanical Performance | Bench testing results demonstrate that Dali Spinal Fixation System performs equivalently to the predicates in: |
- Static compression bending
- Static torsion
- Dynamic compression bending (in accordance with ASTM F1717-10)
- Gripping-push down (in accordance with ASTM F1798) |
| Material Equivalence | The components of this system are manufactured of Titanium alloy (Titanium-6Aluminum-4Vanadium ELI, per ASTM F136) and CoCrMo alloy (Cobalt-28Chromium-6Molybdenum, per ASTM F1537), which are the same materials used in predicate devices. |
| Design Equivalence (substantially similar) | The Dali Spinal Fixation System shares technological characteristics similar to the predicate devices, including similar design. |
| Intended Use / Indications for Use | The device's intended use and indications for use as a non-cervical spinal fixation device (posterior pedicle fixation T1-S2/ilium, or anterolateral fixation T8-L5) for skeletally mature patients as an adjunct to fusion for conditions like degenerative disc disease, spondylolisthesis, trauma, deformities, tumor, stenosis, and failed previous fusion are deemed substantially equivalent to legally marketed predicate devices. |
| Overall Safety and Effectiveness | The Dali Spinal Fixation System is substantially equivalent to the device referenced above and is therefore safe and effective for its intended use. |
2. Sample size used for the test set and the data provenance
The document explicitly states: "Clinical data and conclusions were not needed for this device." This means there was no clinical test set involving human subjects. The evaluation was based on non-clinical (bench) testing. Therefore, there is no sample size for an clinical test set or data provenance (country of origin, retrospective/prospective clinical data).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. As no clinical data was required or used, there was no need for experts to establish ground truth for a clinical test set. The acceptance was based on engineering and material equivalence to predicate devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. No clinical test set with human data requiring adjudication was performed.
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 device is a spinal fixation system (physical implant), not an AI-assisted diagnostic or imaging device. Therefore, an MRMC study related to human reader performance with or without AI assistance is irrelevant and was not 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 a software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the non-clinical performance evaluation, the "ground truth" was established by standardized mechanical testing protocols (e.g., ASTM F1717-10 for dynamic compression bending, and ASTM F1798 for gripping-push down) and material specifications (ASTM F136 for Titanium alloy, ASTM F1537 for CoCrMo alloy). The "truth" was that the device met or exceeded the performance of the predicate devices under these controlled, quantifiable conditions.
8. The sample size for the training set
Not applicable. This device is a physical implant evaluated through bench testing and comparison to predicate devices, not an AI or machine learning model that requires a training set.
9. How the ground truth for the training set was established
Not applicable, as there was no training set.
§ 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.