(22 days)
When intended to promote fusion of the cervical spine and the thoracic spine, (CI-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 radiographic studies), spondylolisthesis, spinal stenosis, fracture, dislocation, failed previous fusion and/or tumors.
Hooks and rods are also intended to provide stabilization to promote fusion following reduction of fracture/dislocation or 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 only. The 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, anchors, transverse connectors, and instruments for inserting and securing the implants.
The subject devices are the result of design modifications made to previously existing Abbott Spine implants intended for use in the posterior spine. The subject devices share the same intended use and fundamental scientific technology as the predicates.
Here's an analysis of the provided text regarding the Koro634 device, focusing on acceptance criteria and supporting studies:
Based on the provided document (KORO634, Nex-Link Spinal Fixation System), it appears this submission is for a 510(k) premarket notification of intent to market, which relies on demonstrating substantial equivalence to a legally marketed predicate device rather than presenting new clinical effectiveness data.
Therefore, the typical structure for reporting acceptance criteria and a study proving device performance (especially for AI/standalone device cases) is not fully applicable here. However, I can extract the relevant information regarding performance and the type of evidence provided.
Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in the format one might expect for a new performance study. Instead, the "acceptance" for this 510(k) relies on demonstrating substantial equivalence to a predicate device. The performance data presented is focused on non-clinical (bench) testing to support this substantial equivalence.
| Acceptance Criteria Category | Specific Criteria (Inferred from 510k) | Reported Device Performance (as per document) |
|---|---|---|
| Safety and Effectiveness | Device is safe and effective in its intended use. | Laboratory and bench testing results demonstrate that the proposed devices are safe and effective in use as intended. |
| Material/Design Properties | The modifications to the predicate device maintain similar functional and mechanical properties. | "The subject devices are the result of design modifications to the predicate devices; they have the same intended use and are substantially equivalent to the predicate devices." |
| Intended Use | The device is suitable for its stated indications for use (cervicothoracic spine fusion). | Document confirms the Nex-Link Spinal Fixation System is indicated for DDD, spondylolisthesis, spinal stenosis, fracture, dislocation, failed previous fusion, and/or tumors in C1-T3. |
Study Details (Based on the provided text)
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Sample size used for the test set and the data provenance:
- Sample Size: Not applicable. The document refers to "Laboratory and bench testing results" but does not specify sample sizes for these tests (e.g., number of implants tested for fatigue, static bending, etc.).
- Data Provenance: Not specified. It's safe to assume these were conducted in a laboratory setting, likely in the US where the submitter is located. This would be retrospective in the sense that the tests are performed on manufactured parts, not in vivo clinical data.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. For mechanical bench testing, "ground truth" is typically established by engineering standards (e.g., ASTM, ISO) or internal specifications, not by expert consensus on diagnostic images or clinical outcomes.
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Adjudication method for the test set:
- Not applicable. Adjudication methods (like 2+1 or 3+1) are relevant for clinical endpoint determination or expert consensus on image interpretation, which are not part of the non-clinical performance data described here.
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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. This document is for a spinal fixation system (physical implant), not an AI device or imaging software. Therefore, an MRMC study is not relevant.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- No. This is a physical medical device. "Standalone" performance as an algorithm is not applicable.
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The type of ground truth used:
- The "ground truth" for the non-clinical performance data would be engineering specifications and established mechanical testing standards (e.g., strength, stiffness, fatigue life). The results of these bench tests are compared against the predicate device's known performance or established industry standards to demonstrate equivalence.
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The sample size for the training set:
- Not applicable. This device is a physical implant, not an AI algorithm requiring a training set.
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How the ground truth for the training set was established:
- Not applicable. As above, no training set for an algorithm is involved.
Summary of Clinical Data (or lack thereof):
The document explicitly states: "Clinical data and conclusions were not needed for this submission." This further emphasizes that the basis for approval (substantial equivalence) rests solely on the non-clinical, laboratory, and bench testing, rather than human clinical trials or performance data.
§ 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.