(30 days)
The Blackstone Spinal Fixation System is intended for non-cervical use in the spine.
The Blackstone Spinal Fixation System, when used for pedicle screw fixation, is intended only for patients:
a) Having severe spondylolisthesis (Grades 3 and 4) at the L5-S1 joint;
b) Who are receiving fusion using autogenous bone graft only;
c) Who are having the device fixed or attached to the lumbar and sacral spine (L3 and below); and
d) Who are having the device removed after the development of a solid fusion mass.
The Blackstone Spinal Fixation System, when used as a pedicle screw system in skeletally mature patients, is intended to provide immobilization and stabilization of spinal segments, as an adjunct to fusion, in treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar and sacral spine:
a) Degenerative spondylolisthesis with objective evidence of neurologic impairment;
b) Fracture;
c) Dislocation;
d) Scoliosis;
e) Kyphosis;
f) Spinal tumor;
g) Failed previous fusion (pseudarthrosis).
The Blackstone Spinal Fixation System, when used for anterolateral non-pedicle screw fixation to the non-cervical spine, is intended for the following indications:
a) Degenerative disc disease (as defined as back pain of discogenic origin with degenerative disc confirmed by history and radiographic studies);
b) Spinal stenosis;
c) Spondylolisthesis;
d) Spinal deformities (i.e., scoliosis, kyphosis, lordosis);
e) Pseudoarthrosis;
f) Tumor;
g) Trauma (i.e., fracture or dislocation).
h) Failed previous fusion.
The Blackstone Spinal Fixation System, when used for posterior non-pedicle screw fixation to the non-cervical spine, is intended for the following indications:
a) Degenerative disc disease (defined as back pain of discogenic origin with degenerative disc confirmed by patient history and radiographic studies);
b) Spinal stenosis;
c) Spondylolisthesis;
d) Spinal deformities (i.e., scoliosis, kyphosis and/or lordosis);
e) Pseudoarthrosis;
f) Tumor;
g) Trauma (i.e., fracture or dislocation);
h) Failed previous fusion.
The Blackstone Spinal Fixation System is a titanium alloy (6AL-4V ELI, per ASTM F136) device comprised of a variety of non-sterile, single use components. The Blackstone Spinal Fixation System Rigid Cross Connector is a modification to the Spinal Fixation System, which allows a surgeon to build a spinal implant construct. The system is attached to the vertebral body by means of screws to the non-cervical spine.
The Blackstone Spinal Fixation System consists of an assortment of screws, hooks, rods, and cross connectors that have received 510(k) clearance (K994217, K013558, K013885, K020674, K023498, K003537).
The provided document is a 510(k) Premarket Notification for a medical device: the Blackstone™ Spinal Fixation System - Rigid Cross Connector. This type of submission focuses on demonstrating substantial equivalence to a legally marketed predicate device, rather than conducting a new standalone clinical efficacy study with specific acceptance criteria and performance metrics described in typical AI/software device submissions.
Therefore, many of the requested data points (such as acceptance criteria, reported device performance, sample size for test/training sets, expert qualifications, adjudication methods, MRMC studies, standalone performance, and ground truth types) are not applicable to this type of regulatory submission for a physical, mechanical medical device.
The study presented here to "prove the device meets acceptance criteria" is a demonstration of substantial equivalence to previously cleared devices, primarily through comparison of design, materials, and intended use.
Here's an attempt to address the points based on the available information, noting where information is not present or not applicable for this type of device:
1. A table of acceptance criteria and the reported device performance
- Acceptance Criteria: For a 510(k) for a mechanical device like this, the "acceptance criteria" are generally based on demonstrating that the modified device (Rigid Cross Connector) performs at least as well as and is as safe and effective as its predicate devices. This is typically achieved through engineering design verification, material testing, and a comparison of intended use, materials, and technological characteristics. The document explicitly states the "Basis of Substantial Equivalence" as the key criterion.
- Reported Device Performance: The document does not provide quantitative performance metrics in the way a software or diagnostic device would (e.g., sensitivity, specificity, accuracy). Instead, "performance" is implicitly demonstrated by the claim of substantial equivalence and by the successful mechanical design to fulfill its intended purpose within a spinal fixation system.
| Criteria | Reported Device Performance |
|---|---|
| Mechanical Equivalence to Predicate Device | The Blackstone™ Rigid Cross Connector is "substantially equivalent to the Blackstone Spinal Fixation System (K994217, K003735)" |
| Material Composition | Made of titanium alloy (6AL-4V ELI, per ASTM F136), consistent with predicate devices and established standards for spinal implants. |
| Intended Use / Indications for Use | Matches the broad range of indications for the predicate Blackstone Spinal Fixation System (detailed in the document for pedicle screw, anterolateral non-pedicle screw, and posterior non-pedicle screw fixation). |
| Technological Characteristics (Design Modification) | The Rigid Cross Connector is described as a "modification to the Spinal Fixation System" that "allows a surgeon to build a spinal implant construct." The implicit acceptance is that this modification does not introduce new safety or efficacy concerns and maintains the overall function of the system. |
| Biocompatibility / Safety (Implied by materials) | Titanium alloy (6AL-4V ELI) is a well-established biocompatible material for implants. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Not Applicable: This is a submission for a mechanical medical device (spinal implant). There is no "test set" of patient data or images in the context of an AI/software device. Compliance is based on engineering design, material specifications, and comparison to predicate devices, not on data analysis from a patient cohort.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Not Applicable: There is no "ground truth" derived from expert consensus on patient data for this type of mechanical device submission. The "truth" is established by engineering principles, material standards, and clinical experience with similar predicate devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not Applicable: There is no "test set" or adjudication process in the context of diagnostic interpretation for this type of device.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- Not Applicable: This is a mechanical spinal implant, not an AI-assisted diagnostic or therapeutic device. Therefore, no MRMC study, human reader improvement, or AI assistance is relevant.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not Applicable: This is a mechanical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Not Applicable / Different Context: For this device, "ground truth" relates to validated engineering principles, material science, and the known clinical performance and safety profile of the predicate devices. It is not derived from patient-specific diagnostic "ground truth" as would be the case for an AI/diagnostic software.
8. The sample size for the training set
- Not Applicable: This is a mechanical device. There is no "training set" of data in the context of machine learning.
9. How the ground truth for the training set was established
- Not Applicable: There is no "training set" for this type of 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.