In-vitro Flexibility Characteristics of Dynamic Pedicle Screw Systems

摘要: In recent years, nonfusion stabilization of the lumbar spine has gained more and popularity. This systems intend to maintain or restore intersegmental motions magnitudes intact have no negative effects on segments adjacent stabilized once. study investigates posterior dynamic devices with different implant stiffness in comparison gold standard dorsal spinal instrumentation, namely fusion. To determine magnitude effect segment, six human cadaver spines were fixed a simulator loaded pure moments alone, additional preload three motion planes. For each spine, five stages tested: native, rigid fixation, fixation two Prototypes Dynesys®. Intersegmental measured at all levels. bridged flexible than fixation. The results showed that there is strong dependency rotation flexion/ extension lateral bending. was not influenced by either method. Our suggests provides substantial stability case degenerative disorders can therefore be considered as an alternative method fusion surgery this indications while segment preserved. But it still unclear which amount should resrticted allowed.