(173 days)
The Spinal Concepts, Inc. BacFix™ ti 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 (T1-SI).
When intended for pedicle screw fixation, the implants are intended for use in Grade 3 and 4 sponylolisthesis at L5-S1, utilizing autologous bone graft, having the device fixed or attached to the lumbar and sacral spine and intended to be removed after solid fusion is attained. Levels of pedicle screw attachment for this indication range from L3 to the sacrum.
When intended for non-pedicle, posterior screw fixation, the system is intended for hook and/or sacral/iliac screw fixation from the thoracic spine to the ileum/sacrum. The indications are:
- Idiopathic scoliosis.
- Neuromuscular 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.
- Revision surgery.
The Spinal Concepts, Inc. BacFix™ ti Spinal Fixation System consists of a combination of titanium 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 (T1-S1). The BacFix™ Spinal Fixation System consists of longitudinal members (spinal rods), in diameters of 5.5 and 6.0mm, in two hardnesses, and a variety of lengths; spinal anchor components, hooks and screws (mono-axial and multi-axial) of various diameters (5.0. 6.0. 7.0 and 8.0mm) and lengths; locking connectors (threaded wedge and nut or non-threaded wedge and locking clip) 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. Wedges are used to connect the spinal rods to screws (hooks and links). These components are preassembled outside the wound, eliminating the need to pre-plan the position of each eyebolt on the spinal rod. A spinal rod is positioned within the open face of the wedge. Fixation of the construct is accomplished using an instrument that applies a three point shear clamp. Addition of the hex nut (when using threaded wedge) and optional use of the locking clip (when using the non-threaded wedge) complete the implant. Anchor components may be added to (or removed from) the construct at any time during the procedure.
The provided document K973687 is a 510(k) premarket notification for a medical device called the "BacFix™ ti Spinal Fixation System." This type of submission is for demonstrating substantial equivalence to a previously approved predicate device, not for proving safety and effectiveness through clinical trials with defined acceptance criteria and performance metrics typically associated with AI/software devices.
Therefore, many of the requested categories for acceptance criteria and study design are not applicable to this type of regulatory submission for a spinal fixation system. However, I can extract the information related to how substantial equivalence was established, which serves a similar purpose in this context.
Here's an analysis based on the provided document:
BacFix™ ti Spinal Fixation System Acceptance Criteria and Study to Prove Conformance
1. Table of Acceptance Criteria and Reported Device Performance
For a spinal fixation system, "acceptance criteria" are typically related to mechanical performance and material properties being comparable to predicate devices. There are no clinical performance metrics like sensitivity/specificity for diagnosis in this type of submission.
| Acceptance Criteria (Proxy for Substantial Equivalence) | Reported Device Performance |
|---|---|
| Material Equivalence: | |
| Components made from Ti-6AL-4V ELI (ASTM F-136), Ti-6AL-7Nb (ASTM F-1295), or unalloyed titanium (ASTM F-67) | Device uses Ti-6AL-4V ELI (ASTM F-136), Ti-6AL-7Nb (ASTM F-1295), & unalloyed titanium (ASTM F-67) |
| Design Equivalence: | |
| Bilateral, dual spinal rods connected with transverse rod linkages. Spinal rods attached to thoracic & lumbar spine with hooks & to sacral spine with screws. | Device described as having "Bilateral, dual spinal rods connected with transverse rod linkages. Spinal rods are attached to thoracic & lumbar spine with hooks & to sacral spine with screws." |
| Functional Equivalence (Mechanical Testing): | |
| Ability to withstand clinical loading and maintain mechanical integrity comparable to predicate devices (BacFix™ Spinal Fixation System & Synthes Universal Spinal System). | "Results of this [static and fatigue] testing demonstrated the BacFix™ ti to be substantially equivalent to the BacFix™ and the Synthes Universal Spine System and able to withstand clinical loading and maintain mechanical integrity." |
| Sterilization: | |
| Achieves a sterility assurance level of 10-6 in accordance with recommended parameters. | Device "must be sterilized prior to use in accordance with the recommended sterilization parameters described in the package insert in order to achieve a sterility assurance level of 10-6." |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not applicable. This is a medical device for implantation, and the "test set" in this context refers to mechanical testing of the device components, not a clinical study on patients. The document does not specify the number of test articles used for static and fatigue testing.
- Data Provenance: The document does not state the country of origin for the mechanical testing data. The testing was conducted internally or by a contracted lab as part of the manufacturer's submission. It is retrospective in the sense that the testing was performed on the device prototypes for regulatory submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Not applicable. For mechanical testing of a spinal fixation system, "ground truth" is established through engineering standards, test methods (e.g., ASTM standards, though not explicitly cited beyond material specs), and direct measurement of physical properties, not expert clinical consensus.
4. Adjudication Method for the Test Set
- Not applicable. This involves engineering testing, not clinical data requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No. An MRMC study is relevant for diagnostic imaging interpretation or other scenarios where human readers make subjective assessments. This is a spinal fixation system, for which such a study is not appropriate.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Not applicable. This is a physical medical device, not a software algorithm.
7. The Type of Ground Truth Used
- For the mechanical testing, the "ground truth" would be the physical properties and mechanical strength measurements (e.g., yield strength, fatigue life, stiffness) of the device components compared against established engineering standards and the performance of predicate devices. This is based on direct physical measurement.
8. The Sample Size for the Training Set
- Not applicable. There is no "training set" in the context of a physical medical device submission for substantial equivalence. The device design and materials are based on established engineering principles and existing predicate devices.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As there is no training set, this question is not relevant. The "ground truth" for the device's design and materials comes from established engineering and biocompatibility standards, and the known characteristics of the predicate devices.
§ 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.