(53 days)
The ST360° Spinal Fixation System is intended for posterior, non-cervical pedicle and nonpedicle fixation for the following indications: degenerative disc disease (DDD) (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma (i.e., fracture or dislocation), spinal stenosis, deformities or curvatures (i.e., scoliosis, and/or lordosis), turnor, pseudoarthrosis, and failed previous fusion. Pedicle screw fixation is limited to skeletally mature patients.
When used as a sacral screw system, the ST360° Spinal Fixation System is intended for use in the treatment of degenerative disease (as defined as chronic back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies), idiopathic scoliosis, spondylolisthesis, kyphotic or lordotic, deformity of the spine, loss of stability due to turnors, spinal stenosis, vertebral fracture or dislocation, pseudoarthrosis, and previous failed spinal fusion. When used for this indication, screws of the ST360° Spinal Fixation System are intended for the sacral iliac attachment only. Transverse connectors of the system are intended for posterior thoracic and/or lumbar use only. As a whole, the levels of use for sacral screw fixation of this system are T1 to the sacrum.
The ST360°® Spinal Fixation System is a temporary implant system used to correct spinal deformity and facilitate the biological process of spinal fusion. This system is intended for posterior use in the thoracic. Iumbar and sacral areas of the spine. Implants of this system consist of screws connected to rods and are intended to be removed after solid fusion has occurred. This system includes polyaxial screws of varying diameters and lengths, rods in varving lengths, and fixed and adjustable transverse connectors. The implants in this system are manufactured from titanium alloy (Ti-6AI-4V ELI), conforming to ASTM F136.
This system's screws, rods, and connectors can be rigidly locked into a wide range of configurations, thereby allowing each construct to be formed to the needs of an individual patient. The ST360° Spinal Fixation System is intended to be used with bone graft which is required to provide additional spinal support.
The provided text is a 510(k) Summary for the ST360°® Spinal Fixation System. It details the device, its intended use, technological characteristics, and importantly, the summary of performance testing conducted to demonstrate substantial equivalence to predicate devices.
Here's an analysis of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the ST360°® Spinal Fixation System are implicitly derived from the performance standards outlined in the ASTM guidelines and the requirement of "substantial equivalence" to the predicate devices. The reported device performance is that it met these standards.
| Acceptance Criteria Category | Specific Test/Standard | Reported Device Performance |
|---|---|---|
| Mechanical Strength & Durability | Static Axial Compression (Bending) (ASTM F1717-12) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. |
| Static Torsion (ASTM F1717-12) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Axial Compression (Bending) Fatigue (ASTM F1717-12) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Static Axial Gripping Capacity (ASTM F1798-97 (Reapproved 2008)) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Static Torsion Gripping Capacity (ASTM F1798-97 (Reapproved 2008)) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Static Flexion-Extension Gripping Capacity (ASTM F1798-97 (Reapproved 2008)) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Static Transverse Moment Gripping Capacity (ASTM F1798-97 (Reapproved 2008)) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Static Axial Torsional Capacity (ASTM F1798-97 (Reapproved 2008)) | Confirmed the product performance of the subject ST360° Spinal Fixation System is suitable for its intended use and substantially equivalent to predicate devices. | |
| Human Factors/Usability | Cadaver Lab Testing (Evaluation of instrument and labeling design changes, interaction with implants) | Confirmed the substantial equivalence of the changes compared to the identified predicate devices. |
| Biocompatibility | Biocompatibility Testing | Ensured the subject ST360° Spinal Fixation System materials are biocompatible after manufacturing based on the minor design changes. |
| Sterilization & Dry Time | Sterilization and Dry Time Testing | Ensured the steam sterilization and dry time requirements and instructions are substantially equivalent to the predicate devices. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document does not explicitly state a numerical sample size for the "bench testing" components (screws, rods, connectors). However, it implies that components of the system were tested. For the human factors/usability testing, it states "a cadaver specimen" was used, which suggests a single specimen.
- Data Provenance: Not explicitly stated (e.g., country of origin). The testing seems to be internal to Zimmer Spine or conducted by external labs on their behalf. The studies are prospective in nature, as they involve testing the actual device components and design changes.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. The "cadaver lab testing" would likely involve orthopedic surgeons or spine specialists, but their number and specific qualifications are not detailed.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable or not specified. This type of device evaluation (bench testing, biocompatibility, cadaver lab for human factors) typically does not involve adjudication in the sense of multiple experts independently reviewing and then resolving discrepancies on a dataset, as would be the case for image-based diagnostic AI. The "ground truth" for the bench tests are measured physical properties against established ASTM standards. For cadaver testing, it's an evaluation of usability and interaction.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- MRMC Study: No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic systems where human readers interpret data (e.g., images) and their performance (with and without AI assistance) is compared. The ST360°® Spinal Fixation System is a surgical implant, not a diagnostic AI system.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Standalone Performance: Not applicable in the context of AI. The "standalone" performance here refers to the device's inherent mechanical properties and material characteristics as tested against established standards, as well as its usability in a simulated environment (cadaver lab). These tests evaluate the device itself, without constant human 'loop' interaction in the sense of a diagnostic interpretation, though human operators are involved in the surgical implantation. The bench tests are essentially "standalone" device performance evaluations in a controlled setting.
7. The Type of Ground Truth Used
- Ground Truth:
- Bench Testing: The ground truth is established by the ASTM F1717-12 and ASTM F1798-97 (Reapproved 2008) standards. These standards define the acceptable mechanical performance limits for spinal implant systems and intervertebral body fusion device systems, respectively. The "ground truth" is that the device must meet or exceed the performance parameters specified in these consensus standards.
- Biocompatibility: The ground truth is the established biocompatibility standards and tests (often ISO 10993 series) for medical devices in contact with biological tissue.
- Sterilization: The ground truth is the established sterilization efficacy standards (e.g., AAMI/ISO standards).
- Cadaver Lab: The ground truth for human factors is subjective expert evaluation of ease of use, instrument interaction, and overall system functionality during simulated surgical procedures.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not applicable. This submission concerns a physical medical device (spinal fixation system), not an AI/machine learning algorithm that requires a "training set" of data.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set Establishment: Not applicable, as there is no AI training set involved.
§ 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.