RIVA Posterior Fixation System; RIVA Posterior Fixation System Navigation Instruments

The RIVA Posterior Fixation System is a non-cervical spinal fixation device intended to provide immobilization and stabilization of the thoracic, lumbar, and sacral spine in skeletally mature patients as an adjunct to fusion. It treats various spinal conditions including degenerative disc disease, spondylolisthesis, trauma, stenosis, deformities, tumors, pseudoarthrosis, and failed previous fusions. The system includes polyaxial pedicle screws, rods, connectors, and instruments, with optional navigation instruments designed for use with the Medtronic StealthStation S8 System.

The device is manufactured from titanium alloy (Ti-6Al-4V ELI per ASTM F136) and/or cobalt chrome alloy (Co-28Cr-6Mo per ASTM F1537 or Co-35Ni-20Cr-10Mo per ASTM F562). It comprises polyaxial pedicle screws, spinal rods, connectors, crossbars, and a separate set screw locking element. The navigation instruments are designed to register and function with the Medtronic StealthStation S8 System for stereotactic surgery applications.

ASTM F1717 and ASTM F1798 were used as reference standards for mechanical performance testing, including static and dynamic compression bending, static torsion, axial and torsional grip, tulip shank dissociation, and flexion-extension testing.

The subject device demonstrates substantially equivalent mechanical performance to predicate devices through identical test methods and standards (ASTM F1717 and F1798). Navigation instruments were validated for compatibility with the Medtronic StealthStation S8 System through accuracy testing and dimensional analysis. The device uses the same material compositions and design approach (polyaxial screws with rod fixation) as established predicate devices. Since technological differences do not raise new or different questions of safety and effectiveness, and intended use and indications are identical, substantial equivalence is established.