[Dynamic posterior stabilization with the pedicle screw system DYNESYS®].

OBJECTIVE

The dynamic neutralization system for the spine (DYNESYS®) is a pedicle screw based system intending mobile restabilization substituting physiological tissue restraints and thus approximating the unstable motion pattern to a normal pattern. It consists of titanium alloy screws, connected by an elastic synthetic compound (PET band and PCU spacer) controlling motion in any plane. DYNESYS® can be used for mono- or multilevel stabilizations in the lumbar spine.

INDICATIONS

DYNESYS® is indicated in the treatment of degenerative disease of the lumbar motion segment with instability and most often in combination with functional or structural spinal canal stenosis.

CONTRAINDICATIONS

Primary and secondary bone tumors of the spine. Spinal fractures. Infections. Lytic/isthmic spondylolisthesis. Degenerative spondylolisthesis > I°-II°. Facetectomy. Stabilization of thoracic and cervical spine. Allergies to components of DYNESYS®. Pregnancy.

SURGICAL TECHNIQUE

Standard midline approach. Decompression of the segment by laminotomy if indicated. Place the screws lateral to the facet joints. Measure the distance between the screw heads. Cut the spacers. Introduce spacer and cord on both sides. The length of the PCU spacer is determined by the distance of the pedicle screws and depends on the pathology of the lumbar motion segment. Tighten set screws under correct compression of the system.

POSTOPERATIVE MANAGEMENT

Mobilisation at the first day after surgery. No bracing necessary if there is no doubt about primary fixation of the screws. Physical strenuous work not earlier than 8 weeks postoperatively.

RESULTS

DYNESYS® is a reliable dynamic stabilization system with good clinical results if used in correct indications.