(35 days)
The Spinal Concepts, Inc. BacFix™ Spinal Fixation System consists of a combination of components which include rods, hooks, locking wedges, screws and transverse connectors which are indicated to provide temporary stability of the thoracic, thoracolumbar or lumbar spine (T)-SI).
When intended for pedicle screw fixation, implants are 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, kyphosis, spinal tumor and failed previous fusion (pseudarthrosis). Levels of pedicle screw attachment for these indications range from T1 to the sacrum.
In addition, when intended for pedicle screw fixation, implants are intended for treatment of severe spondylolisthesis (grades 3 and 4) of the vertebra in skeletally mature patients receiving fusion by autogenous bone graft having implants attached to the lumbar and sacral spine with removal of implants after the attainment of solid fusion. The levels of screw fixation for these indications range from L3 to the sacrum.
When intended for non-pedicle, posterior screw fixation of the noncervical spine, the indications are:
- Idiopathic scoliosis.
- Neuromuscular scoliosis/kyphoscoliosis with associated paralysis or spacticity.
- 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 degeneration of the disc confirmed by history and radiographic studies).
- Neoplastic disease.
- Spondylolisthesis.
- Spinal stenosis.
- Failed previous fusion.
The BacFix™ Spinal Fixation System consists of longitudinal members (spinal rods), in a variety of diameters (1/4" and 3/16") and lengths; spinal anchor components, hooks and screws, of various sizes (6.0-7.5mm diameter screws) and types; locking connectors (wedge and nut) sized to fit the spinal rods; and a transverse connector assembly (link), also in various lengths. Hooks and screws may be placed at any position along the spinal rods and are secured with a three point shear clamp (wedge and nut). The open face of the wedge may be snapped over the spinal rod. Thus the component and wedge may be preassembled outside the wound, eliminating the need to attach the nut within the surgical opening and the need to pre-plan the position of each eyebolt on the spinal rod. Furthermore, an anchor component may be added to (or removed from) the construct at any time during the procedure.
The provided document describes the BacFix™ Spinal Fixation System (K983258), a medical device. The "study" that proves the device meets acceptance criteria is a mechanical testing comparison study rather than a clinical trial involving human subjects. This is a common approach for Class II medical devices seeking 510(k) clearance, where substantial equivalence to a legally marketed predicate device is the primary pathway.
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Withstand clinical loading | "demonstrated the BacFix™ to be substantially equivalent to the Zimmer Modulock Posterior Spinal System and the Sofamor Danek TSRH Spinal System and able to withstand clinical loading" |
| Maintain mechanical integrity | "demonstrated the BacFix™ to be substantially equivalent to the Zimmer Modulock Posterior Spinal System and the Sofamor Danek TSRH Spinal System and able to ... maintain mechanical integrity." |
| Substantial equivalence to predicate devices (Zimmer Modulock, Sofamor Danek TSRH) in material, design, and function | The entire "Substantial Equivalence" section (III) details the claimed equivalence in materials (316L Stainless Steel & 22-13-5 Stainless Steel), design (longitudinal members, hooks, screws, locking connectors, transverse connector assembly), and function (indications for use, as confirmed by mechanical testing). |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact number of test samples (e.e. rods, screws, hooks) used for the static and fatigue mechanical testing.
- Data Provenance: Not explicitly stated, but the testing would have been conducted in a laboratory setting, likely in the US, as the company is based in Austin, Texas. It is a prospective test in the sense that the device was manufactured specifically for these tests. It is not related to patient data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- This question is not applicable in the traditional sense for this type of mechanical testing. The "ground truth" for mechanical testing is established by engineering standards and comparative data with predicate devices, not by expert consensus on clinical cases. The comparison was to published data of predicate devices.
4. Adjudication Method for the Test Set
- Not applicable. Mechanical testing data is evaluated against pre-defined engineering standards and comparative data, not through an adjudication process by human experts.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC study was not done. This is a mechanical device, and its approval is based on substantial equivalence to predicate devices through material and mechanical performance, not through a comparative effectiveness study involving human readers or clinical outcomes in the way AI/radiology devices might.
6. Standalone Performance Study
- Yes, a standalone study was done, but it's mechanical. The "Mechanical Testing" section (VII) describes static and fatigue testing performed solely on the BacFix™ System. The results of this standalone testing were then compared to published data of "various other hook, rod and screw spinal fixation systems." This is a standalone performance of the device's mechanical properties, not a standalone algorithm performance.
7. Type of Ground Truth Used
- The "ground truth" for this device's performance evaluation is based on:
- Engineering Standards: Implied standards for static and fatigue strength for spinal fixation systems.
- Predicate Device Performance Data: Published mechanical testing data from the Zimmer Modulock Posterior Spinal System and the Sofamor Danek TSRH Spinal System.
8. Sample Size for the Training Set
- Not applicable. This device is a physical medical implant, not an AI/ML algorithm that requires a "training set" of data.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As above, there is no "training set" for a physical medical 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.