(147 days)
The VERSALOK™ Screw Assembly is supplied as an alternative component for use with the WRIGHTLOCK™ Postedor Spinal Fixation System to fix the spine for appropriate indications apply when used as a pedicle screw.
A WRIGHTLOCK™ construct with screws attached to the pedicies of the lumbar and sacral spine (L3 to S1) and autogenous bone graft may be used for the treatment of severe spondylolisthesis (Grade 3) at the fith lumbar - first sacral (LS-S1) vertebral joint. The device is intended to be implanted using a posterior surgical approach and removed after development of a solid fusion mass.
When not used as a pedicle screw fixation system, various combinations of the system are also indicated to provide temporary stability of the thoracic, thoracolumbar. or lumbar spino (T1 to S1) during bony fusion healing secondary to: (1) Unstable spinal fractures (such as fracture diskcations) or spinal tumors; (2) Degeneralive disk diseases of the spine (defined as back pain of diskogenic origin with degeneration of the disk confirmed by radiographic studies); (3) Spinal curvatures (such as idiopathic scoliosis/kyphoscoliosis with associated paralysis or spasticity, and secondary to spinal fractures) which are: progressive, despite other forms of treatment; detrimental to cardiopulmonary function; interfering with spinal mechanics or causing severe back pain; or cosmetically unacceptable, progressive, and painful.
The VERSALOK™ Screw Assembly is a polyaxial screw assembly consisting of screws, locking sleeves, and caps. The system is designed to accommodate the rods of the commercially available WRIGHTLOCK™ Posterior Spinal Fixation System (K950074-SE 08/11/95). The system features a low profile as well as a top loading design. It allows for up to 8mm offset from the rod and up to 30 degrees of angulation in all planes prior to final locking. The VERSALOK™ Screw Assembly is available in a range of sizes to fit varying anatomical requirements.
The provided text describes a medical device, the VERSALOK™ Screw Assembly, and its performance. However, the information you've requested regarding acceptance criteria, study details, and data provenance for typical AI/ML medical devices is not present in this document. This document is a 510(k) Summary for a traditional implantable medical device (spinal fixation system component), not an AI/ML diagnostic or prognostic device.
Therefore, I cannot extract the following information from the provided text:
- A table of acceptance criteria and the reported device performance: This document reports mechanical test results, not clinical performance metrics like sensitivity, specificity, AUC, or Dice scores, which are typical for AI/ML devices.
- Sample size used for the test set and the data provenance: No test set of patient data is mentioned; the testing refers to mechanical integrity.
- Number of experts used to establish the ground truth for the test set and their qualifications: Not applicable to mechanical testing.
- Adjudication method for the test set: Not applicable to mechanical testing.
- If a multi-reader multi-case (MRMC) comparative effectiveness study was done: Not applicable.
- If a standalone performance (algorithm only without human-in-the-loop) was done: Not applicable as it's not an algorithm.
- The type of ground truth used: Not applicable as it's mechanical testing.
- The sample size for the training set: Not applicable as it's not an AI/ML model.
- How the ground truth for the training set was established: Not applicable.
What is present in the document is:
- Device Performance (Mechanical Testing Summary):
- Fatigue endurance limit: 353N
- Axial pull strength: 1086N
- Torsional grip strength: 1.95Nm
The document states, "Based on these results, the VERSALOK™ Screw Assembly should perform adequately when subjected to normal physiological loading." This implies that these mechanical performance metrics serve as the "acceptance criteria" for the device's physical integrity and functionality in a mechanical sense, rather than clinical efficacy as would be required for 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.