(117 days)
The M.U.S.T. Pedicle Screw System is intended for posterior non-cervical pedicle fixation (T1-S2/ilium) and nonpedicle fixation, or anterolateral fixation (T8-L5). These devices are indicated as an adjunct to fusion for all of the following indications: degenerative disc disease (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies); spondylolisthesis; trauma (i.e., fracture or dislocation); spinal stenosis; curvatures (i.e., scoliosis, kyphosis, and/or lordosis); tumor; pseudoarthrosis and failed previous fusion in skeletally mature patients.
The M.U.S.T. Extension is intended to be used as part of the M.U.S.T. pedicle screw system (K121115, K132878) for the stabilization and the fusion of the lumbar and thoracic spine. The M.U.S.T. pedicle screw system includes cannulated or non cannulated poly-axial pedicle screws (K12115, K132878), cannulated or non cannulated mono-axial pedicle screws (K132878), set screws (K121115), straight and pre-bent rods (K12115), and cross connectors (K132878). The M.U.S.T. Extension consists of the following components, which are all provided in both sterile and unsterile packaging: Wide blade hook, Pedicle hook, Pedicle hook screw, Angled hook, Offset hook, Narrow blade hook.
The provided text describes the M.U.S.T. Extension device as an adjunct to the M.U.S.T. Pedicle Screw System. The document is an FDA 510(k) premarket notification and primarily focuses on demonstrating substantial equivalence to predicate devices rather than proving the device meets specific acceptance criteria through a standalone study.
1. Table of Acceptance Criteria and Reported Device Performance:
The document states that "design verification was conducted to written protocols with pre-defined acceptance criteria." However, it does not explicitly list these acceptance criteria or present the detailed results of the device's performance against them in a table format. Instead, it relies on geometrical comparisons and the assumption that the new components are not "worst case" compared to predicate devices for which testing was previously done.
2. Sample Size for Test Set and Data Provenance:
The document does not describe a separate "test set" in the context of an AI/algorithm. The focus is on physical device testing. The "geometrical comparisons" mentioned do not involve a sample size of patient data or data provenance. The assessment is based on the design of the device components.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
Not applicable. This document pertains to a medical device's physical and mechanical properties, not an AI algorithm requiring expert ground truth for a test set.
4. Adjudication Method for the Test Set:
Not applicable for the reasons stated above.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No MRMC study was done, as this document is for a physical medical device (pedicle screw system components), not an AI-assisted diagnostic tool.
6. Standalone (i.e., algorithm only without human-in-the-loop performance) Study:
No standalone algorithm study was done or is applicable to this device submission.
7. Type of Ground Truth Used:
The "ground truth" in this context refers to established engineering and biomechanical principles and standards used for evaluating the performance of implantable devices. The document implies compliance with these standards based on the geometric similarity to predicate devices. There is no biological or clinical "ground truth" derived from patient data described.
8. Sample Size for the Training Set:
Not applicable. There is no AI algorithm being trained or evaluated in this submission.
9. How Ground Truth for the Training Set Was Established:
Not applicable for the reasons stated above.
Summary of Device Acceptance and Study Information from the Text:
The document asserts that the M.U.S.T. Extension is substantially equivalent to its predicate devices based on:
- Indications for Use: They are the same as the predicate devices.
- Design Features: The M.U.S.T. Extension components (hooks, screws) have similar design features to existing components in the M.U.S.T. system (K121115, K132878) and other predicate devices.
- Materials: All components are made from Ti6Al4V ELI (ISO 5832-3/ASTM F 136), which is a commonly accepted material for such implants and is consistent with predicate devices.
- Performance Testing (Reaffirmation based on geometric comparison):
- A risk analysis was conducted to identify new risks.
- Design verification was performed with predefined acceptance criteria based on standards, FDA guidance, and comparison to predicate devices.
- Geometrical comparisons were performed for the implant/rod/set screw interface (hooks) and implant/bone interface (hooks).
- It was determined that "There were not any additional tests performed on the hooks as the interface to the rod, the tulip and thread geometry, the set screw and the final tightening torque are exactly the same as for the M.U.S.T. monoaxial screws (K132878)."
- Conclusion: "Therefore, the biomechanical implant performance regarding yield strength, fatigue strength and construct stiffness can be considered at least equal to the predicate devices."
The study described is not a clinical trial or an AI algorithm validation. It is a design verification and substantial equivalence demonstration based on engineering principles, material science, and comparison to previously cleared predicate devices, arguing that the new components perform at least as well as the already tested existing components. The acceptance criteria and "proving" of the device are implied through conformity with established standards for similar devices and the principle of substantial equivalence rather than explicit, novel performance benchmarks.
§ 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.