(57 days)
The Uni-Thread Spinal System is a pedicle screw system indicated for skeletally mature patients who:
- have severe spondylolisthesis (Grades 3 and 4) at the L5-S1 vertebra;
- receive fusions using autogenous bone graft only;
- have the device fixed or attached to the lumbar and sacral spine (L3 to sacrum); and
- have the device removed after the development of a solid fusion.
In addition, the Uni-Thread Spinal System is a pedicle screw system 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:
- Degenerative spondylolisthesis with objective evidence of neurologic impairment
- fracture
- dislocation
- scoliosis
- kyphosis
- spinal tumor
- failed previous fusion (pseudoarthrosis)
The Uni-Threaad Spinal System instrumentation consists of screws, rods, and connectors that can be assembled in a variety of constructs. The instrumentation is combined and placed to treat a variety of spinal disorders, with the constructs varying according to the nature of the spinal pathology. The Uni-Thread System components are available in titanium alloy manufactured according to ASTM-F136.
The Uni-Thread™ Spinal System is a pedicle screw spinal system. The provided text, a 510(k) summary, indicates that this device received clearance based on its substantial equivalence to previously cleared devices. This means that the device's safety and effectiveness were demonstrated through comparison to predicate devices rather than a standalone clinical study with predefined acceptance criteria.
Therefore, the typical structure for reporting acceptance criteria and a study proving their fulfillment is not directly applicable here in the way it would be for a de novo device or one requiring a PMA.
Here's a breakdown of the available information based on your request, with an emphasis on how "substantial equivalence" impacts the answers:
1. A table of acceptance criteria and the reported device performance:
Since the clearance is based on substantial equivalence, there are no specific, quantitative acceptance criteria for clinical performance in the provided document that the device had to meet in a standalone study. Instead, the "acceptance criteria" were demonstrating equivalence in design, materials, and mechanical performance to predicate devices.
| Acceptance Criteria (Implied for Substantial Equivalence) | Reported Device Performance (Summary) |
|---|---|
| Design Equivalence to Predicate Devices | Components are identical in design to other FDA-cleared spinal instrumentation systems. |
| Material Equivalence to Predicate Devices | Components are identical in material (titanium alloy manufactured to ASTM-F136) to other FDA-cleared spinal instrumentation systems. |
| Intended Use Equivalence to Predicate Devices | Components are identical in intended use to other FDA-cleared spinal instrumentation systems. |
| Mechanical Performance Equivalence | Mechanical testing was performed to demonstrate the equivalence of the construct design to currently marketed spinal systems. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
No clinical or human-based test set with a specified sample size is mentioned in the 510(k) summary. The "test set" in this context refers to the mechanical testing samples. The document does not specify the sample size, country of origin, or whether the mechanical testing data was retrospective or prospective.
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):
Not applicable as there was no clinical study described that required expert-established ground truth. The device's equivalence was based on engineering and material comparisons, not diagnostic or therapeutic outcomes requiring expert review.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
Not applicable for the same reasons as point 3.
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 mechanical implant (pedicle screw system), not an AI-assisted diagnostic or therapeutic tool. Therefore, an MRMC study is irrelevant.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
No standalone clinical performance study was conducted or reported in this summary. The device was cleared based on substantial equivalence and mechanical testing, not a clinical trial.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
For the mechanical testing, the "ground truth" would be the established performance standards or specifications for predicate devices or relevant ASTM standards for spinal implants. This is based on engineering principles and material science, not clinical outcomes or expert consensus on patient data.
8. The sample size for the training set:
Not applicable. This is a medical device, not an AI or machine learning algorithm that requires a training set.
9. How the ground truth for the training set was established:
Not applicable for the same reasons as point 8.
In summary: The provided 510(k) summary for the Uni-Thread™ Spinal System indicates clearance through the substantial equivalence pathway. This pathway primarily relies on demonstrating that a new device is as safe and effective as a legally marketed predicate device, often through design, material, and mechanical performance comparisons, rather than extensive new clinical trials with predefined acceptance criteria and human subject data analysis.
§ 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.