Biomechanics of Internal Fixation System

摘要: Many of the surgical procedures concerning lumbar spine involve dissection soft tissues and often removal impinging structures.’ Such may bony architecture to allow for satisfactory decompression neural elements. It is necessary surgically fuse segments stability. Internal fixation with instrumentation accompanies fusion augment spinal stability enhance postoperative mobilization patient. However, use devices considered somewhat controversial.2-6 The rationale as treatment low back pain originates from idea that painful symptoms caused by a degenerated or unstable motion segment can be relieved.7-‘7 On other hand, some investigators believe should not encouraged because adverse iatrogenic effects outweigh positive results. For example, number have noted an increase in stenosis/spondylolysis, both above below level, which they believed was excessive stress on adjacent intervertebral discs.‘6J-21 Because these controversies, biomechanical evaluations various systems are needed afford basic understanding issues associated internal devices. A briefdescription studies reported literature follows. An extensive bibliography also provided further in-depth study. three aspects: anatomical considerations component design system,22-25 overall imparted “injured” specimen particular instrumentation, characterization load-displacement behavior specifically across stabilized segments. results characteristics device shown most currently effective restoring injured specimens flexion/extension, although degree effectiveness varies among different devices.26-29 do provide insights into injured/stabilized levels levels. quantification parameters requires testing multilevel methodology used preparing whole obtained very briefly described following paragraphs.‘s30-33