(96 days)
The M.U.S.T. pedicle screw system is intended for posterior non-cervical pedicle fixation (T1-S2/ilium) 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 consists of the following implants that are to be used as part of the M.U.S.T. pedicle screw system (K121115):
- New sizes (diameter and length) of the solid polyaxial pedicle screws that were cleared under K121115
- Solid and cannulated monoaxial pedicle screws
- Cross connectors
The M.U.S.T. Extension is intended to be used as part of the M.U.S.T. pedicle screw system for the stabilization and the fusion of the lumbar and thoracic spine. The M.U.S.T. Extension includes different sizes of screws and cross connectors. The screws are fixed in the pedicle and the vertebrae. The straight and pre-bent rods (K121115) act as a connector between the different screws to create a stable construct. The cross connectors act as a stabilizing construct between the rods on each side of the vertebrae. The cross connectors have an adjustable medial/lateral length in order to address various distances between the rods depending on the patient's anatomy. Rod distances from 35mm to 98 mm can be addressed with the various connector sizes. The connector offers an angular adjustable central joint in order to align the connection to the rod. The anqular adjustable feature as well as the size range of the connectors is within the range of the predicate devices. The M.U.S.T. Extension can be applied with the common surgical technique for posterior instrumentation.
The M.U.S.T. Extension cross connectors are made of Titanium alloy (Ti6AI4V ELI -ISO 5832-3, ASTM F136) and come in 4 sizes: 35-42, 40-50, 48-66, and 64-98. The M.U.S.T. Extension pedicle screws are made of either Titanium alloy (Ti6Al4V ELI - ISO 5832-3, ASTM F136) or a combination of Titanium alloy (Ti6AI4V ELI - ISO 5832-3, ASTM F136) and CoCrMo (ISO 5832-12, ASTM F 1537). The M.U.S.T. Extension solid polyaxial pedicle screws have diameters of 8, 9, and 10mm and lengths between 20 and 100mm in 5mm increments. The M.U.S.T. Extension solid monoaxial pedicle screws have diameters between 4.5 and 7mm and lengths between 25 and 65mm in 5mm increments in addition to screws with a diameter of 8mm with lengths between 25 and 90mm. The M.U.S.T. Extension cannulated monoaxial pedicle screws have diameters between 5 and 7mm and lengths between 40 and 60mm in 5mm increments. The screw shaft is color anodized to simplify the identification of the screw diameter. The pedicle screw has a dual lead thread to simplify the screw insertion and reduce the number of turns. The threads are designed with a cylindrical diameter. The construct is secured using a set screw made of CoCrMo (ISO 5832-12, ASTM F 1537). The pedicle screws are available both in sterile and unsterile packaging while the cross connectors are available in sterile packaging.
The provided text describes a medical device, the M.U.S.T. Extension, and its substantial equivalence to predicate devices, rather than a study proving performance against acceptance criteria for an AI/ML powered device. The document is a 510(k) summary for a spinal pedicle screw system extension.
Therefore, many of the requested categories for AI/ML device studies (such as sample size for test sets, data provenance, number of experts, adjudication methods, MRMC studies, standalone performance, training set size, and how training ground truth was established) are not applicable to this submission.
However, I can extract the acceptance criteria and a description of the testing performed for this mechanical device.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Based on Standards and Predicate Devices) | Reported Device Performance (Compared to Predicate Devices) |
|---|---|
| Static compression/bending yield strength (ASTM F 1717) | M.U.S.T. Extension is not worst case compared to predicate devices for this test. |
| Fatigue compression/bending strength (ASTM F 1717) | M.U.S.T. Extension is not worst case compared to predicate devices for this test. |
| Static compression/bending stiffness (ASTM F 1717) | M.U.S.T. Extension is not worst case compared to predicate devices for this test. |
| Static torsion yield strength (ASTM F 1717) | M.U.S.T. Extension is not worst case compared to predicate devices for this test. |
| Static torsion stiffness (ASTM F 1717) | M.U.S.T. Extension is not worst case compared to predicate devices for this test. |
Study Description:
The study performed was a design verification study to evaluate the M.U.S.T. Extension's mechanical properties.
- Objective: To demonstrate that the M.U.S.T. Extension is substantially equivalent to its predicate devices in terms of mechanical performance.
- Methodology:
- A risk analysis was conducted to identify any new risks associated with the changes in the M.U.S.T. Extension.
- Design verification tests were conducted according to written protocols with predefined acceptance criteria.
- These protocols and acceptance criteria were based on established standards (specifically ASTM F 1717), FDA guidance, and comparison to existing predicate devices.
- Testing was performed on the "worst case component size and option/design based on engineering analysis."
- The M.U.S.T. Extension's performance was compared to the "worst case of the predicate devices."
2. Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated as a number of devices. "Worst case component size and option/design" was tested.
- Data Provenance: Not applicable in the context of clinical data. This is mechanical testing data for new device components.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. Ground truth for mechanical testing is based on engineered specifications and established standards, not expert consensus on clinical data.
4. Adjudication method for the test set:
- Not applicable. Mechanical testing results are objectively measured against predefined thresholds.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done:
- No, this was not a MRMC comparative effectiveness study. It was mechanical testing of a medical device's components.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This device is a mechanical implant, not an algorithm.
7. The type of ground truth used:
- For mechanical properties, the "ground truth" or reference was based on established industry standards (ASTM F 1717) and the performance of currently marketed, legally predicate devices. The acceptance criteria were derived from these standards and predicate device performance.
8. The sample size for the training set:
- Not applicable. This is not an AI/ML device requiring a training set.
9. How the ground truth for the training set was established:
- Not applicable. This is not an AI/ML 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.