Indications Dynesys LIS System, Dynesys Top-Loading System & Zimmer DTO System When used as a pedicle screw fixation system in skeletally mature patients, the Dynesys Spinal System is intended to provide immobilization and stabilization of spinal segments as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: degenerative spondylolisthesis with objective evidence of neurologic impairment, and failed previous fusion (pseudoarthrosis).In addition, when used as a pedicle screw fixation system, the Dynesys Spinal System is indicated for use in patients: Who are receiving fusions with autogenous graft only; Who are having the device fixed or attached to the lumbar or sacral spine; Who are having the device removed after the development of a solid fusion mass. When the Dynesys Spinal System and the OPTIMA* ZS Spinal Fixation System are used on contiguous levels, they must be used with the Zimmer DTO Implant, rod-cord combination implant, and the U&i Corporation OPTIMA ZS Transition Screw. The intended use for each level is as specified for each system.