(68 days)
When intended for pedicle screw fixation from T1 -S1, the Sequoia® Pedicle Screw System is 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 disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), degenerative spondytolisthesis with objective evidence of neurologic impairment, fracture, dislocation, deformities or curvatures (i.e. scollosis, kyphosis, and/or lordosis), tumor and failed previous fusion.
As a pedicle screw system placed between L3 and S1, the indications include Grade 3 or Grade 4 spondylolisthesis, when utilizing autologous bone graft, when affixed to the posterior lumbosacral spine, and intended to be removed after the solid fusion is established.
When intended for non-pedicle, posterior screw fixation of the non-cervical spine (T1-S1), the indications are idiopathic scoliosis, neuromuscular scoliosis with associated paralysis or spasticity, scoliosis with deficient posterior elements such as that resulting from laminectomy or myelomeningocele, spinal fractures (acute reduction or late deformity). degenerative disc disease (back pain of discogenic origin with degenerative of the disc confirmed by history and radiographic studies), tumor, spondylolisthesis, spinal stenosis and failed previous fusion.
The Sequoia® Pedicle Screw System consisting of open style polyaxial screws, titanium rods (varying lengths) and connectors is intended to provide temporary stabilization following surgery to fuse the spine. The polyaxial screw design allows the surgeon to use a top-loading technique for dropping the spinal rod down to the fixation components into a u-shaped opening. SpeedLink II ™ Transverse Connectors are provided to increase rotational stiffness to the final construct.
The provided document does not describe a study that uses acceptance criteria in the typical sense for evaluating device performance in a clinical or diagnostic context. Instead, this is a 510(k) summary for a medical device (Zimmer Spine Sequoia® Pedicle Screw System) seeking regulatory clearance based on substantial equivalence to predicate devices. The "performance testing" described is primarily bench testing and evaluations to confirm the updated device's equivalence in design, materials, and mechanical properties to previously cleared devices.
Therefore, many of the typical questions regarding acceptance criteria for diagnostic devices, sample sizes for test sets, expert ground truth, and comparative effectiveness studies are not applicable in this context.
Here's an analysis based on the information provided:
Acceptance Criteria and Device Performance (Based on Substantial Equivalence)
The acceptance criteria for this 510(k) submission are implicitly tied to demonstrating substantial equivalence to predicate devices in terms of design, materials, function, intended use, and performance characteristics. The "performance" here refers to mechanical and physical properties relevant to a spinal implant, rather than diagnostic accuracy or clinical outcomes.
| Acceptance Criteria Category | Reported Device Performance (as demonstrated for Substantial Equivalence) |
|---|---|
| Mechanical Performance (Implants) | Confirmed as suitable for intended use through bench testing (static compression bending, dynamic compression bending, and static torsion testing per ASTM F1717 & F1798 as applicable). |
| Human Factors (Instrument & Labeling Interaction) | Evaluated as substantially equivalent to predicate devices through cadaver lab testing regarding instrument design changes and labeling. |
| Biocompatibility | Materials confirmed as biocompatible after manufacturing (for minor design changes compared to predicates). |
| Sterilization, Dry Time, and Cleaning Instructions | Confirmed as substantially equivalent to predicate devices for steam sterilization, cleaning, and dry time instructions. |
| Design, Materials, Function, Intended Use | The current device shares the same technological characteristics (design, materials, sizes) and a subset of the indication for use as the predicate device. |
| Product Performance Specifications / Functional Technology | No changes to product performance specifications or device functional scientific technology compared to the predicate. |
Study Information (Based on 510(k) Premarket Notification)
Since this is a submission for substantial equivalence of a modified medical device, the categories requested often pertain to diagnostic or AI-driven devices. The "studies" described here are engineering and physical tests.
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not specified in terms of number of screws, rods, or connectors tested. The document generally states "components of the current Sequoia® Pedicle Screw System... were reviewed and tested."
- Data Provenance: The testing was "Bench testing" (mechanical simulation) and "Cadaver lab testing." This suggests laboratory-controlled environments. No country of origin for test data is explicitly mentioned, but the submitting company is Zimmer Spine, Inc. in Minneapolis, MN, USA. The testing appears to be prospective for the modified device to demonstrate its equivalence.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Ground Truth Establishment: For mechanical bench testing, "ground truth" would be established by engineering standards (e.g., ASTM F1717 & F1798). These standards define the test methods and expected performance characteristics, not by experts in the typical clinical sense.
- Expert Involvement: For "Cadaver lab testing... to evaluate human factors regarding the combination of instrument design changes and labeling design changes, as well as interaction with implants," it would imply surgeons or medical professionals were involved in using the system on cadavers. However, the number and qualifications of these experts are not specified. The purpose was to confirm "substantial equivalence of the changes compared to the identified predicate devices," not to establish a new clinical ground truth.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable. Adjudication methods like 2+1 or 3+1 are typically used for reconciling disagreements among expert readers in diagnostic image interpretation or similar qualitative assessments. The tests described are objective, quantitative engineering tests (bench testing) and human factors evaluations.
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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, an MRMC comparative effectiveness study was not done. This type of study is relevant for AI-assisted diagnostic devices. The device in question is a spinal implant for stabilization, not a diagnostic tool.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. This question pertains to AI algorithms. The device is a physical pedicle screw system.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the bench testing, the "ground truth" or reference for performance is established by engineering standards (ASTM F1717 & F1798). The device's performance is compared against these standards and against the performance of the predicate devices.
- For biocompatibility, the ground truth is established by biocompatibility testing standards and regulatory requirements for medical device materials.
- For human factors/cadaver lab testing, the "ground truth" is likely the practical usability and equivalence observed by the participating professionals when installing the device compared to the predicate.
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The sample size for the training set:
- Not applicable. There is no "training set" in the context of this physical medical device. This term applies to machine learning models.
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How the ground truth for the training set was established:
- Not applicable. As there is no training set, this question is not relevant.
§ 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.