(111 days)
The Polaris Spinal System is a non-cervical spinal fixation device intended for immobilization and stabilization as an adjunct to fusion as a pedicle screw fixation system, a posterior hook and sacral/iliac screw fixation system, or as an anterolateral fixation system. Pedicle screw fixation is limited to skeletally mature patients and for use with autograft. The device is indicated for all the following indications: degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma, (i.e., fracture or dislocation), deformity or curvature (i.e., scoliosis, and lordosis), tumor, stenosis, pseudarthrosis, and failed previous fusion.
The Ballista instruments are intended to be used with the 5.5 Polaris implants. The Ballista instruments when used with the Ballista cannulated screws and percutaneous rods, are indicated to provide the surgeon with a percutaneous approach for posterior spinal surgery for the following indications: degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma, (i.e., fracture or dislocation), deformity or curvature (i.e., scoliosis, and lordosis), tumor, stenosis, pseudarthrosis, and failed previous fusion that warrant the use of a non-cervical spinal fixation device intended for use as a pedicle screw fixation system or sacral/iliac screw fixation system. Pedicle screw fixation is limited to skeletally mature patients and for use with autograft.
The AccuVision Instruments, when used with the Polaris Spinal System implants are indicated to provide the surgeon with a minimally invasive approach for posterior spinal surgery for the following indications: degenerative disc disease (defined as discogenic back pain with degeneration of the disc confirmed by history and radiographic studies), spondylolisthesis, trauma, (i.e., fracture or dislocation), deformity or curvature (i.e., scoliosis, kyphosis, and lordosis), tumor, stenosis, pseudarthrosis, and failed previous fusion that warrant the use of a non-cervical spinal fixation device intended for use as a pedicle screw fixation system or sacrabiliac screw fixation system. Pedicle screw fixation is limited to skeletally mature patients and for use with autograft.
This submission is a line extension to the Polaris Spinal System to add new uniplanar screws fabricated from titanium.
Based on the provided text, the Polaris Spinal System is a medical device, and its acceptance criteria and the study proving it meets these criteria are described as follows:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion (Study Endpoint) | Reported Device Performance (Result) |
|---|---|
| Static Compression Bending | Substantially equivalent |
| Static Torsion | Substantially equivalent |
| Dynamic Compression Bending Fatigue | Substantially equivalent |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly mention a "test set" in the context of clinical data for the uniplanar screws. Instead, the evaluation focuses on mechanical testing.
- Sample Size: Not specified for the mechanical tests, beyond the implication that multiple tests were performed per ASTM standards.
- Data Provenance: The mechanical testing was "conducted in accordance to ASTM 1717-04 Standard Test Methods for Static and Fatigue for Spinal Implant Constructs in a Vertebrectomy Model." This refers to laboratory-based mechanical testing, not human or animal study data.
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not applicable to this submission, as the evaluation was based on mechanical testing, not clinical expert review or diagnostic performance.
4. Adjudication Method for the Test Set
This is not applicable, as there was no test set involving human assessment or adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The submission is for a line extension of a spinal fixation system, focusing on mechanical equivalence.
6. Standalone (Algorithm Only) Performance Study
Not applicable. The device is a physical spinal implant system, not a software algorithm.
7. Type of Ground Truth Used
The "ground truth" for the mechanical testing was the specifications and performance characteristics set forth by the ASTM 1717-04 Standard Test Methods for Static and Fatigue for Spinal Implant Constructs in a Vertebrectomy Model, and the performance of predicate devices. The goal was to demonstrate substantial equivalence to these established standards and predicate devices.
8. Sample Size for the Training Set
Not applicable. This device is a physical surgical implant, not an AI/ML algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
Study Proving Device Meets Acceptance Criteria
The study that proves the device meets the acceptance criteria is mechanical testing performed in accordance with ASTM 1717-04 Standard Test Methods for Static and Fatigue for Spinal Implant Constructs in a Vertebrectomy Model.
The document states:
"Mechanical testing (conducted in accordance to ASTM 1717-04 Standard Test Methods for Static and Fatigue for Spinal Implant Constructs in a Vertebrectomy Model) included static compression bending, static torsion and dynamic compression bending fatigue. Based upon the mechanical testing, these screws are substantially equivalent for their intended use to other spinal systems currently on the market."
The "acceptance criteria" here are implicitly defined by achieving performance that is "substantially equivalent" to predicate devices and consistent with the established ASTM standards for the mechanical properties tested (static compression bending, static torsion, and dynamic compression bending fatigue). The study concluded that the new uniplanar screws met this "substantial equivalence" based on the mechanical test results.
§ 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.