(89 days)
The General Spinal System is intended for posterior pedicle screw fixation of the non-cervical posterior spine in skeletally mature patients. It provides stabilization and immobilization of spinal segments as an adjunct to fusion in the treatment of the following acute and chronic instabilities deformities: (1) trauma (i.e. fracture or dislocation), (2) curvatures (scoliosis, kyphosis, and/or lordosis), (3) spinal tumor, (4) failed previous fusion, (5) pseudarthrosis, (6) spinal stenosis. It is not intended for pedicle screw fixation above T8.
The General Spinal System consists of Fixed-Angle Screws, Fix-Angle Reduction Screws, Hooks, Rods, Cross Link and Set Screws. It is made of Titanium Alloy (Ti6Al4VELI), which meets ASTM F136-02a, Standard Specification for Wrought Titanium-6 Aluminum-4 Vanadium ELI (Extra Low Interstitial) Allov for Surgical Implant Applications. which are widely used for surgical implants with well known biocompatibility. The proposed devices are provided non-sterile. It is required to be sterilized via autoclave method to reach a SAL of 10 by the hospital prior to surgery. The recommended sterilization method was validated per ISO 17665-1: 2006 Sterilization of health care products -- Moist heat -- Part 1: Requirements for the development, validation, and routine control of a sterilization process for medical devices
This document describes the General Spinal System, a pedicle screw spinal system. The primary method of demonstrating acceptance criteria for this device is through non-clinical testing, specifically mechanical performance testing, and comparison to a legally marketed predicate device to establish substantial equivalence.
1. Table of Acceptance Criteria and Reported Device Performance
| Parameter | Acceptance Criteria (Standard) | Reported Device Performance (Test Results) |
|---|---|---|
| Mechanical Performance | ASTM F1717-04: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model | Complies with the standard. |
| Static compression bending | As per ASTM F1717-04 | Met specifications. |
| Dynamic compression bending | As per ASTM F1717-04 | Met specifications. |
| Static torsion | As per ASTM F1717-04 | Met specifications. |
| Material Biocompatibility | ASTM F136-02a: Standard Specification for Wrought Titanium-6 Aluminum-4 Vanadium ELI (Extra Low Interstitial) Alloy for Surgical Implant Applications | Made of Titanium Alloy (Ti6Al4VELI) meeting this standard, confirming well-known biocompatibility. |
| Sterilization Efficacy | ISO 17665-1:2006 Sterilization of health care products -- Moist heat -- Part 1: Requirements for the development, validation, and routine control of a sterilization process for medical devices | Recommended sterilization method was validated to reach a SAL (Sterility Assurance Level) of 10^-6. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document does not specify exact sample sizes (e.g., number of constructs tested) for each mechanical test performed under ASTM F1717-04. It only states that "Non clinical tests were conducted to verify that the proposed device met all design specifications."
- Data Provenance: The tests are non-clinical (laboratory tests) conducted by Tianjin Walkman Biomaterial Co., Ltd. in China. The data provenance is internal testing, not patient data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- This information is not applicable. The "ground truth" for non-clinical performance evaluations of medical devices like spinal systems is typically established by recognized national/international standards (e.g., ASTM, ISO), which define test methodologies, acceptance criteria, and performance limits. These standards are developed and maintained by committees of experts, but specific "experts" assigned to establish "ground truth" for a particular device's test set are not mentioned or required in this context.
4. Adjudication Method for the Test Set
- This information is not applicable. The non-clinical tests involve objective measurements (e.g., load, displacement) against specified performance criteria, rather than subjective interpretation requiring adjudication among multiple parties.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This type of study is relevant for diagnostic imaging devices where human interpretation of images is a key factor. This submission pertains to a surgical implant (pedicle screw spinal system), where performance is assessed through mechanical testing and material properties.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- This is not applicable. The device is a physical surgical implant, not a software algorithm.
7. The Type of Ground Truth Used
- The "ground truth" for the device's performance in this context is defined by established engineering and material standards. Specifically:
- Mechanical Integrity: ASTM F1717-04 defines the "ground truth" for appropriate mechanical performance characteristics (static/dynamic bending, torsion) expected of spinal implant constructs.
- Material Biocompatibility: ASTM F136-02a defines the "ground truth" for the material properties and biocompatibility of the titanium alloy used.
- Sterilization: ISO 17665-1:2006 defines the "ground truth" for a validated sterilization process to achieve a specified Sterility Assurance Level.
8. The Sample Size for the Training Set
- This information is not applicable. The device is a physical medical device, not an AI/ML algorithm that requires a training set. The design and manufacturing process are informed by general engineering principles and material science, not a data-driven "training" process in the AI sense.
9. How the Ground Truth for the Training Set Was Established
- This information is not applicable as there is no "training set" for this device.
§ 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.