(27 days)
When intended to promote fusion of the cervical spine and the thoracic spine, (C1-T3), the NexLink Spinal Fixation System is indicated for the following:
DDD (neck pain of discogenic origin with degeneration of the disc confirmed by history and DDD (neck pain of discogeme oright my spinal stenosis, fracture, dislocation, failed previous fusion and/or tumors.
Hooks and rods are also intended to provide stabilization to promote fusion following Hooks and rous are uiso intentiou to trauma in the cervical/upper thoracic (C1-T3) spine.
The use of multiaxial screws is limited to placement in T1-T3 in treating thoracic conditions The use of multiaxial screws are not intended to be placed in the cervical spine.
The Nex-Link Spinal Fixation System is intended for fixation to, and stabilization of, the cervicothoracic spine (C1-T3). The system consists of a series of longitudinal members, connectors, and instruments for inserting and securing the implants.
The subject device, the Variable Crosslink, represents a design modifications made to the predicate device, the Nex-Link Spinal Fixation System (K031985) or others. The subject device shares the same intended use and fundamental scientific technology as the predicate.
This document is a 510(k) premarket notification for a medical device, the Nex-Link Spinal Fixation System Variable Crosslink. The information provided heavily emphasizes comparison to a predicate device and bench testing. It explicitly states that clinical data and conclusions were not needed for this device. Therefore, the document does not contain the detailed information typically found in a clinical study report that would address many of your specific questions.
Here's the breakdown of what can be extracted and what cannot:
1. A table of acceptance criteria and the reported device performance
Since this is a 510(k) clearance based on substantial equivalence and non-clinical data, there are no "acceptance criteria" in the sense of clinical performance metrics (e.g., sensitivity, specificity) with target values. The "performance" reported is primarily that the device is substantially equivalent to a predicate device based on bench testing.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Substantial equivalence to predicate device (Nex-Link Spinal Fixation System, K031985) | "Laboratory and bench testing results demonstrate that the proposed device is substantially equivalent to the predicate device." |
| Meets the same intended use and fundamental scientific technology as the predicate device | "The subject device shares the same intended use and fundamental scientific technology as the predicate." |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size for Test Set: Not applicable. The "test set" here refers to the non-clinical (bench) tests conducted. The document does not specify the number of samples or tests conducted in the laboratory and bench testing.
- Data Provenance: Not applicable. The data is from laboratory and bench testing, not clinical data about patients from a specific country or in a retrospective/prospective study design.
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. There was no clinical ground truth established by experts as clinical data was not required or provided. The "ground truth" for bench testing would be engineering specifications and standards.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. This concept applies to clinical studies where expert consensus or adjudication is used to resolve discrepancies in diagnoses or outcomes. It is not relevant for bench testing.
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 MRMC study was done. This device is a physical spinal implant, not an AI-powered diagnostic tool. The concept of human readers and AI assistance does not apply.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. This device is a physical spinal implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Ground Truth: For the non-clinical tests, the "ground truth" would be established engineering standards, design specifications, and performance characteristics of the predicate device against which the modified device was compared. Clinical ground truth was not used or required.
8. The sample size for the training set
- Not applicable. There was no training set, as no machine learning algorithm was developed or evaluated.
9. How the ground truth for the training set was established
- Not applicable. There was no training set.
§ 888.3050 Spinal interlaminal fixation orthosis.
(a)
Identification. A spinal interlaminal fixation orthosis is a device intended to be implanted made of an alloy, such as stainless steel, that consists of various hooks and a posteriorly placed compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The device is used primarily in the treatment of scoliosis (a lateral curvature of the spine), but it also may be used in the treatment of fracture or dislocation of the spine, grades 3 and 4 of spondylolisthesis (a dislocation of the spinal column), and lower back syndrome.(b)
Classification. Class II.