(113 days)
It is intended for patients with severe spondylolisthesis (Grades 3 and 4) having fusions at the L5-S1 joint using autogenous bone graft, to be fixed/attached to the lumbar and sacral spine. The components are intended to be removed after development of a solid fusion mass. The screws are limited to L3-S1 or iliac screw fixation.
The DDS Spinal System is a multi-component system consisting of pedicle screws, rods and spacers. The screws are available in five lengths and one diameter; the rods in twelve lengths and the spacers in three thicknesses. The screws are fabricated from titanium alloy (Ti-6Al-4V) that conforms to ASTM F136 The screws have a 6,5 mm thread diameters and are available in five lengths, 35, 40, 45, 50 and 55 mm. The rods are also manufactured from Ti-6Al-4V and are 5 mm in diameter. The rods are available in 12 lengths ranging from 40 mm to 600 mm. Round, smooth spacers of three different heights (2, 4, and 6 mm) slide over the threaded portion of the screw to facilitate implantation of neighboring screws at the same level. The spacers are also made of Ti-6Al-4V.
The provided text describes the DDS Spinal System, a medical device, and presents test results. However, it does not contain the information required to answer your specific questions related to acceptance criteria, device performance, study details, expert involvement, or ground truth establishment in the context of an AI/algorithm study.
The document is a Summary of Safety and Effectiveness for a physical medical device (spinal fixation system) cleared in 1996. The "Test Results" section refers to mechanical testing of the device components (e.g., axial compression, bending, torsion), not an evaluation of an artificial intelligence algorithm or its diagnostic/predictive performance.
Therefore, I cannot provide the requested information for the following reasons:
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Acceptance Criteria and Device Performance Table: The provided "Test Results" table details mechanical properties of the spinal system (Max. Load, Deformation, Stiffness) which are acceptance criteria for the physical device's structural integrity, not for an AI algorithm's performance (e.g., sensitivity, specificity, AUC).
- Device Performance (as per document):
- Axial Compression: $1403.2\pm90.6$ N (Max. Load), $2.69\pm.61$ mm (Deformation), $929.2\pm117.6$ N/mm (Stiffness)
- Bending: $24.38\pm.63$ Nm (Max. Load), $20.86\pm1.67$ mm (Deformation), $3.07\pm.53$ Nm/mm (Stiffness)
- Torsion: $42.30\pm2.44$ Nm (Max. Load), 38 degrees (Deformation), $2.58\pm.09$ Nm/deg (Stiffness)
- Screw Pullout* (Unembedded): $818.5\pm341.8$ N (Max. Load)
- Screw Pullout** (Wrapped, embedded): $785.0\pm289.7$ N (Max. Load)
- Acceptance Criteria: The document implies that these performance values were acceptable for clearance but does not explicitly state the numerical targets or thresholds that constituted the "acceptance criteria" for each test.
- Device Performance (as per document):
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Sample size for test set and data provenance: Not applicable to an AI study. The "test set" here refers to the number of physical specimens tested (e.g., 5 for axial compression, 16 for unembedded screw pullout). Data provenance is not relevant in this context.
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Number of experts and qualifications: Not applicable. These tests were mechanical engineering tests, not human expert evaluations of an algorithm's output.
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Adjudication method: Not applicable. There was no need for expert adjudication.
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Multi Reader Multi Case (MRMC) comparative effectiveness study: Not applicable. This is not an AI algorithm.
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Standalone (algorithm only) performance: Not applicable. This is a physical device.
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Type of ground truth: Not applicable. The "ground truth" for mechanical tests would be the measured physical properties themselves, not expert consensus or pathology.
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Sample size for training set: Not applicable as there is no AI algorithm being "trained."
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How ground truth for training set was established: Not applicable.
In summary, the provided document describes a physical medical device and the mechanical testing performed on its components to demonstrate its safety and effectiveness. It does not pertain to an AI/algorithm, and therefore, most of your questions cannot be answered from this text.
§ 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.