(27 days)
The Polyaxial Hemispherical Spinal Screws are intended for posterior, noncervical pedicle and non-pedicle 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; curvatures (i.e., scoliosis, and/or lordosis); tumor; pseudoarthrosis; and failed previous fusion.
As a pedicle screw system the Polyaxial Hemispherical Spinal Screws are intended for the treatment of severe spondylolisthesis (Grade 3 and 4) of the L5-S1 vertebrae in skeletally mature patients receiving fusion by autogenous bone graft having implants attached to the lumbar and sacral spine (L3 to sacrum) with removal of the implants after the attainment of a solid fusion.
The ISOBAR Spinal System consists of monoaxial and polyaxial pedicle screws rods, nuts and cross link members. (K990118, K013447 and K031290) It can be used for single or multiple level fixation. It also includes single and double hooks (K013444 and K013440) used for posterior, nonpedicle screw fixation of the noncervical spine, hook and sacral/iliac screw fixation to the noncervical spine and hook and sacral screw fixation to the T1-S1 spine.
The modification included in this submission is the addition of polyaxial hemispherical screws. These screws function in the same manner as the previously cleared hemispherical screws by insertion into the pedicle then placing an offset clamp over the screw with a rod that has been loaded into the clamp. A nut is them placed on the screw and tightened to secure the assembly. The new polyaxial screw allows the proximal portion of the screw to angulate in order to ease the assembly of the rod loaded clamps onto multiple screws that may not be axially aligned.
Here's an analysis of the provided text regarding the acceptance criteria and study for the Polyaxial Hemispherical Spinal Screws:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What was measured?) | Reported Device Performance (How did it perform compared to the predicate?) |
|---|---|
| Mechanical performance as per ASTM F1717 (Static and dynamic compression bending, static and dynamic torsion, static and dynamic axial pullout, implant-to-implant connection strength, corrosion resistance, and fatigue strength) | "Testing was performed per ATM F1717 and the results are comparable to the predicate device." |
2. Sample Size Used for the Test Set and Data Provenance
The provided summary does not explicitly state a sample size for the test set. It mentions "Testing was performed per ATM F1717," which is a standard for pedicle screw spinal systems. This implies that the tests outlined in ASTM F1717 would have been conducted on a sufficient number of devices to demonstrate equivalence.
The data provenance is commercial, with the submitter being Scient'x, located in France. The testing would have been conducted by the manufacturer or a contracted lab in support of U.S. market clearance. The submission is retrospective in the sense that the testing was performed before the 510(k) submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not applicable to this type of device submission. For a mechanical device like a spinal screw, the "ground truth" is established by adherence to a recognized international standard (ASTM F1717) and the physical properties of the materials and design, not by expert interpretation of data like in medical imaging.
4. Adjudication Method for the Test Set
This is not applicable to this type of mechanical testing. Adjudication methods like 2+1 or 3+1 are used for expert review of subjective data (e.g., medical images). The results of ASTM F1717 are objective measurements.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating the performance of diagnostic or screening devices, particularly those involving human interpretation of data, and how an AI system might improve that human performance. This is a mechanical implant device.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
This question is not applicable as this is a mechanical spinal implant, not an AI algorithm.
7. The Type of Ground Truth Used
The "ground truth" for the performance of the Polyaxial Hemispherical Spinal Screws relies on engineering specifications and recognized international standards (ASTM F1717). The comparison is made against the performance of a previously cleared predicate device that presumably also met these standards.
8. The Sample Size for the Training Set
This question is not applicable. This is a mechanical device, not an AI/ML algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable. As explained above, there is no "training set" for this type of device.
Summary of the Study:
The "study" or rather, the non-clinical testing, performed to demonstrate the device meets acceptance criteria was based on ASTM F1717, a standard specification for spinal pedicle screw systems. The crucial aspect of the study was to show that the modified device (Polyaxial Hemispherical Spinal Screws) performed comparably to its predicate device (Scient'x ISOBAR Hemispherical Screw system). The specific performance metrics would have included various mechanical tests such as static and dynamic compression bending, torsion, axial pullout, implant-to-implant connection strength, corrosion resistance, and fatigue strength, as described in ASTM F1717. The acceptance criteria essentially were to meet or exceed the performance characteristics of the predicate device under these standardized conditions. The FDA's clearance (K051063) indicates that the agency found the results of this testing sufficient to establish substantial equivalence.
§ 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.