(100 days)
The Zodiac® Polyaxial Spinal Fixation System is intended for use as a posterior spinal fixation device to aid in the surgical correction of various spinal deformities and pathologies of the spine. It is intended to provide stabilization during the development of fusion utilizing a bone graft. Specific indications for the Zodiac® Polyaxial Spinal Fixation System are dependent in part on the configuration of the assembled device and the method of attachment to the spine.
It is intended that this device, in any system configuration, be removed after development of solid fusion mass. Hook component indications are limited to T7-L5. Sacral-iliac screw indications are limited to the sacrum-iliac crest only.
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The Zodiac® Polyaxial Spinal Fixation System when used as a hook and sacral iliac screw fixation system (nonpedicle screw) is intended for:
a. Patients having fractures of the thoracic and lumbar spine.
b. Patients having deformity (i.e. idioscoliosis, neuromuscular scoliosis or kyphoscoliosis with associated paralysis or spasticity).
c. Patients having spondylolisthesis (i.e. isthmic spondylolisthesis, degenerative spondylolisthesis, and acute pars fracture allowing spondylolisthesis). -
The Zodiac® Polyaxial Spinal Fixation System, when used as a pedicle screw system in the thoraco-lumbo-sacral iliac region of the spine is intended for degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, spinal tumor and failed previous fusion (pseudoarthrosis).
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In addition, the Zodiac® Polyaxial Spinal Fixation System, when used as a pedicle screw system is intended for:
a. Patients receiving autograft or allograft bone.
b. Patient having the device fixed or attached to the lumbar and sacral iliac spine and having severe spondylolisthesis grade 3 or 4 at the fifth lumbar-first sacral (L5-S1) vertebral joint. -
The Zodiac® Polyaxial Spinal Fixation System, when used as a laminar hook and bone screw system is intended for:
a. Patients having fractures of thoracic and lumbar spine.
b. Patients having thoracolumbar deformity (i.e. idioscoliosis, neuromuscular scoliosis, kyphoscoliosis or kyphoscoliosis with associated paralysis or spasticity),
c. Patients having spondylolisthesis (i.e. Isthmic spondylolisthesis, degenerative spondylolisthesis and acute pars fracture allowing spondylolisthesis).
The Zodiac® Polyaxial Spinal Fixation System is intended for use as a posterior spinal fixation device to aid in the surgical correction of various spinal deformities and pathologies in the thoracolumbo-sacral liac portion of the spine. It is intended to provide stabilization during the development of fusion utilizing a bone graft. Specific indications for the Zodiac® Polyaxial Spinal Fixation System are dependent in part on the configuration of the assembled device and the method of attachment to the spine. The Zodiac® Polyaxial Spinal Fixation System unplants are manufactured from Titanium Alloy conforming to ASTM F136 or ASTM F67, Stainless Steel conforming to ASTM F138 or ASTM F2229, or Cobalt Chrome conforming to ASTM F799 or ASTM F1537.
The Alphatec Spine, Inc. Zodiac® Polyaxial Spinal Fixation System received 510(k) clearance (K100685) in 2010. The clearance was based on demonstrating substantial equivalence to predicate devices through mechanical and dynamic testing.
Here's an analysis of the provided information:
1. Table of Acceptance Criteria and Reported Device Performance
Acceptance Criteria for Substantial Equivalence (Inferred from testing and FDA clearance process):
The primary acceptance criterion for this 510(k) submission was to demonstrate substantial equivalence to previously cleared predicate devices by showing comparable mechanical and dynamic performance. This is typically achieved by meeting or exceeding performance metrics established by relevant ASTM standards, specifically ASTM F1717 for spinal implant constructs.
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Static compression values (ASTM F1717) equivalent to predicate devices. | Equivalent: "Static compression values are equivalent to the previously cleared legally marketed Alphatec Spine predicate devices." |
| Static torsion values (ASTM F1717) equivalent to predicate devices. | Equivalent: "Static torsion values are equivalent to previously cleared legally marketed Alphatec Spine predicate devices confirming substantial equivalence." |
| Critical dynamic compression run out value (ASTM F1717) identical to predicate devices. | Identical: "The critical dynamic compression run out value is identical to the previously cleared legally marketed Alphatec Spine predicate devices confirming substantial equivalence." |
| Torsional stability of Uniplanar screw (Simulated Derotation Testing) comparable to or better than predicate. | Improved: "Testing of the Uniplanar screws showed a much higher ultimate moment during torsional loading compared to the predicate." (This suggests the new Uniplanar screw design exhibited superior torsional stability, which would meet or exceed equivalence requirements). |
Note: The acceptance criteria are inferred based on common practices for 510(k) submissions of spinal fixation systems, where mechanical testing to established ASTM standards against predicate devices is the usual route to demonstrate substantial equivalence. The document explicitly states the conclusions of the testing in relation to the predicate devices.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact number of devices or constructs tested for each mechanical test (e.g., number of samples for static compression, static torsion, dynamic compression, or simulated derotation). Mechanical testing for medical devices typically involves a specific number of samples as defined by the relevant ASTM standards to achieve statistical significance.
- Data Provenance: The data is from pre-clinical mechanical testing conducted by the manufacturer, Alphatec Spine, Inc. It is laboratory-generated data, not from human subjects or patient populations. There is no country of origin of data mentioned other than the company being located in Carlsbad, CA, suggesting the testing was performed within the US or under the company's purview. It is inherently retrospective in the sense that the testing was performed and then reported for the 510(k) submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This section is not applicable. The "ground truth" for mechanical testing is based on objective measurements against established engineering standards (ASTM F1717) and direct comparison to the performance of predicate devices. It does not involve expert clinical judgment or consensus in the way a diagnostic AI device would.
4. Adjudication Method for the Test Set
This section is not applicable. As stated above, the "test set" here refers to mechanical test results, which are objectively measured against defined criteria, not human interpretations requiring adjudication.
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
This section is not applicable. This submission is for a spinal fixation system (a physical implantable device), not a diagnostic AI or imaging device that would involve human readers or AI assistance in interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This section is not applicable. This is a physical medical device, not an algorithm or AI system.
7. The Type of Ground Truth Used
The "ground truth" for this submission is established through:
- Mechanical Performance Standards: Conformance to established ASTM F1717 physical and mechanical testing standards.
- Predicate Device Performance: Direct comparative performance against previously cleared, legally marketed predicate devices from Alphatec Spine, Inc. The predicate devices themselves represent "ground truth" in terms of acceptable mechanical performance for the intended use. These predicates are: K033090, K042673, K051286, K071890, and K093077.
8. The Sample Size for the Training Set
This section is not applicable. The concept of a "training set" applies to machine learning or AI models. This submission is for a physical medical device and relies on engineering principles and mechanical testing.
9. How the Ground Truth for the Training Set Was Established
This section is not applicable for the same reason as point 8.
§ 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.