(25 days)
The CapLOX II® / TowerLOX® Pedicle Screw System is a posterior, non-cervical pedicle fixation system 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 including degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, scoliosis, kyphosis, spinal tumor, pseudarthrosis and failed previous fusion.
In addition, when used as a pedicle screw fixation system, the CapLOX II® / TowerLOX® Pedicle Screw System is intended for skeletally mature patients with severe spondylolisthesis (Grades 3 and 4) of the fifth lumbar-first sacral, L5-S1 vertebra, who are receiving fusion by autogenous bone graft only, who are having the device attached to the lumbar and sacral spine (levels may be from L3 to the sacrum/ilum), who are having the device removed after the attainment of a solid fusion.
The CapLOX II® / TowerLOX® MIS Pedicle Screw System is an implant device made from a titanium alloy Ti-6Al-4V ELI per ASTM F136. It is to be implanted from the posterior approach. The screws are currently available in diameters from 4.9-9.0mm and in lengths from 30-100mm. The line extension will include the addition of 4.9-9.0mm extended tab screws to be marketed as TowerLOX® EXT MIS Extended Tab Pedicle Screws in lengths of 30-100mm. All screws with a 5.5mm, 6.5mm and 7.5mm screw diameters will have an updated tip angle. The set screws currently have a 5mm hex, will also be available with a T25 Torx interface. Additional instrumentation will also be added to the system. Overall, the system includes set screws, pedicle screws, and rods with the associated instrumentation in order to complete the procedure and implant construct when performed using minimally invasive surgical techniques.
This FDA 510(k) premarket notification describes the CapLOX II® / TowerLOX® MIS Pedicle Screw System, a pedicle screw system, as a line extension. This means it is based on a previously cleared predicate device (CapLOX II® / TowerLOX® Pedicle Screw System, K131538). The submission focuses on demonstrating substantial equivalence to this predicate device by highlighting that the new components do not introduce new safety or effectiveness concerns.
Here's an analysis of the provided information concerning acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative "acceptance criteria" in the format of a table with numerical goals and reported performance values. Instead, it relies on demonstrating substantial equivalence to a predicate device. The primary "performance" reported is that the modifications (extended tab pedicle screws, updated screw tip angle, additional set screw interface) do not create a new worst case when compared against the predicate devices and were concluded as not raising any new issues for safety and effectiveness. This implies that the device performs at least as well as the predicate device in terms of safety and effectiveness.
The document highlights the following similarities and an implied performance level:
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Materials of manufacture | Identical (titanium alloy Ti-6Al-4V ELI per ASTM F136) to predicate |
| Structural support mechanism | Identical to predicate |
| Indications for Use | Identical to predicate |
| No new worst case | Modifications assessed using risk management and concluded not to create a new worst case |
| No new safety/effectiveness issues | Assessed and concluded not to raise any new issues for safety and effectiveness |
2. Sample Size Used for the Test Set and Data Provenance
The document does not describe a "test set" in the context of clinical data for evaluating the device's performance. This submission is for a line extension of a medical device, and the evaluation relies on demonstrating that the new components are substantially equivalent to the previously cleared predicate device. This typically involves non-clinical performance testing (e.g., mechanical, material characterization) rather than a clinical study with a patient "test set". Therefore, information regarding sample size, country of origin, or retrospective/prospective nature for a clinical test set is not applicable here.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Since there is no "test set" in a clinical context as described above, this information is not applicable. The "ground truth" for this type of submission largely rests on compliance with established material and mechanical standards, and engineering analysis comparing the new components to the predicate. Internal engineering experts and regulatory affairs personnel within Captiva Spine, Inc. would have been involved in this assessment.
4. Adjudication Method for the Test Set
As there is no clinical "test set" described, an adjudication method is not applicable.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating the performance of diagnostic or AI-assisted devices where human readers interpret medical images or data. The CapLOX II® / TowerLOX® MIS Pedicle Screw System is an implantable surgical device, and its evaluation does not involve human readers interpreting data in this manner.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
No, a standalone (algorithm only) performance study was not done. This concept is relevant for AI/ML-driven devices. This submission concerns a physical implantable device, not an algorithm.
7. The Type of Ground Truth Used
The "ground truth" for this submission is based on:
- Material properties data: Conformance to ASTM F136 for titanium alloy Ti-6Al-4V ELI.
- Mechanical testing data: Implied by the statement "These modifications have been assessed using risk management techniques and were concluded as not creating a new worst case when compared against the predicate devices." This typically involves bench testing (e.g., fatigue, static strength) to ensure the new components meet or exceed the performance characteristics of the predicate.
- Engineering analysis: Comparing the design and function of the new extended tab screws, updated tip angle, and set screw interfaces to the predicate device to determine that no new safety or effectiveness concerns are introduced.
8. The Sample Size for the Training Set
There is no "training set" in the context of this device submission. This refers to data used to train AI models, which is not applicable here.
9. How the Ground Truth for the Training Set Was Established
As there is no "training set," this question is not applicable.
§ 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.