(29 days)
The Xia® Spinal System is intended for use in the noncervical spine. When used as a pedicle screw fixation system, the Xia® Spinal System is intended for patients: (a) having severe spondylolisthesis (Grades 3 and 4) at the fifth lumbar - first sacral (L5-S1) vertebral joint; (b) who are receiving fusions using autogenous bone graft only; (c) who are having the device fixed or attached to the lumbar and sacral spine; and (d) who are having the device removed after the development of a solid fusion mass.
When used as a pedicle screw fixation system, the Xia® Spinal System is also 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 spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, spinal tumor, and failed previous fusion (pseudarthrosis).
When used as an anterior screw fixation system or a posterior hook and sacral/iliac screw fixation system, the Xia® Spinal System is indicated for patients with degenerative disc disease which is defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies, spondylolisthesis, fracture, spinal stenosis, spinal deformities such as scoliosis, kyphosis, lordosis, tumor, pseudoarthrosis or revision of failed fusion attempts.
The 6mm diameter rods from the DIAPASON™ Spinal System and OPUS™ Spinal System are intended to be used with the other components of the Xia® Titanium Spinal System. The Titanium Multi-Axial Cross Connectors are intended to be used with the other components of the Xia® Titanium Spinal System.
The Stryker Spine Xia " Spinal Fixation System consists of Monoaxial and Polyaxial Screws, Washer, Hooks, Blocker, Rods, Staples, and Connectors. The components are manufactured from either Titanium material (Ti alloy and CP Titanium) or Stainless Steel.
This submission is intended to address a line extension to Xia® Spinal System. The line extension includes the addition of Titanium alloy and Stainless Steel 4.0 mm diameter spinal screws.
The provided 510(k) Premarket Notification is for a medical device, specifically a line extension to the Xia® Spinal System, rather than an AI/ML powered device. As such, the typical acceptance criteria and study designs associated with AI/ML device performance (e.g., sensitivity, specificity, MRMC studies, training/test sets, ground truth establishment by experts) are not applicable or described in this document.
The document focuses on establishing substantial equivalence to predicate devices through comparisons of intended use, material, basic design concepts, and mechanical properties.
Here's an analysis based on the information provided, framed as if it were an AI/ML device for illustrative purposes, but highlighting that these specific criteria are not met by the document itself.
1. A table of acceptance criteria and the reported device performance
Since this is a line extension for a spinal fixation system, the "acceptance criteria" are not quantitative performance metrics like those for AI/ML. Instead, they relate to demonstrating that the new components perform similarly to the predicate devices and meet established safety and effectiveness standards for spinal implants.
| Acceptance Criterion (Hypothetical for AI/ML) | Reported Device Performance (as per 510(k) for mechanical device) |
|---|---|
| Primary Performance Metric: (e.g., Sensitivity for disease detection) | Not Applicable (N/A). The device is a spinal implant, not an AI diagnostic. Performance is assessed through mechanical testing and comparison to predicates. |
| Secondary Performance Metric: (e.g., Specificity) | N/A. |
| Safety Criterion: (e.g., False Positive Rate below X%) | Demonstrated Mechanical Equivalence: "Mechanical testing also demonstrated comparable mechanical properties to the predicate device: Stryker Spine Xia® Spinal System (K013823) and DePuy Inc. Moss Miami Spinal System (K962628)." This implies the new components are safe and perform as expected structurally, similar to previously cleared devices. |
| Clinical Efficacy (if applicable): (e.g., Improved patient outcomes) | Substantial Equivalence in Intended Use: The device shares the "same intended use" as the predicate. This is a primary criterion for 510(k) clearance, indicating comparable clinical efficacy to a legally marketed device. |
2. Sample size used for the test set and the data provenance
- Sample Size: Not applicable in the context of an AI/ML test set. The "testing" involved mechanical evaluations of the physical components. The document doesn't specify the number of screws or rods tested, but rather states that "Mechanical testing also demonstrated comparable mechanical properties." This refers to laboratory-based physical tests, not a dataset of patient information.
- Data Provenance: Not applicable for an AI/ML test set. The "data" comes from mechanical test results of the manufactured spinal system components.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. For a medical device like a spinal implant, ground truth regarding its mechanical performance is established through standardized engineering tests (e.g., fatigue, static strength) and comparison to established predicate devices. There wouldn't be "experts" establishing a diagnostic ground truth in the way a radiologist would for an AI algorithm. The regulatory body (FDA) reviews the test methods and results, and the qualifications of the engineers performing the tests would be relevant, but are not detailed here.
4. Adjudication method for the test set
- Not Applicable. Adjudication methods (like 2+1, 3+1) are used to resolve disagreements among human annotators when establishing ground truth for AI/ML datasets. For mechanical testing, the results are typically quantitative and objective, though statistical analysis and interpretation by qualified engineers would be involved.
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
- Not Applicable. MRMC studies are specifically designed to evaluate the impact of AI assistance on human reader performance in diagnostic tasks. This device is a surgical implant and does not involve human "readers" or AI assistance in this context.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not Applicable. This refers to a medical device's performance in a diagnostic or analytical capacity without human intervention. The Xia® Spinal System is a physical implant, not an algorithm.
7. The type of ground truth used
- Not Applicable in the AI/ML sense. The "ground truth" for this device's acceptance is based on:
- Mechanical Testing Standards: Adherence to recognized industry standards for spinal implant performance (e.g., fatigue, static tests).
- Predicate Device Performance: Direct comparison of the new devices' mechanical properties and intended use to existing, legally marketed predicate devices (Xia® Stainless Steel System, Xia® Spinal System, DePuy Inc., Moss Miami Spinal System). The presumption is that if the new device performs mechanically equivalent to a cleared predicate, it is safe and effective for its intended use.
8. The sample size for the training set
- Not Applicable. There is no "training set" for a physical medical implant device in the AI/ML context.
9. How the ground truth for the training set was established
- Not Applicable. As there is no training set mentioned typical for AI/ML development, this question is not relevant to the provided documentation.
§ 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.