Intrathecal volume changes in lumbar spinal canal XXXX following extension and flexion: An experimental cadaver study.

@entity1 @entity353 @entity612 @entity2649 @entity850
BACKGROUND: The spinal canal @entity850 is a common disease in elderly. The thecal sac narrowing is considered as the anatomical cause for the disease. There is evidence that the anatomical proportions of the lumbar spinal canal are influenced by postural changes. The liquor volume shift during these postural changes is a valuable parameter to estimate the dynamic qualities of this disease. OBJECTIVE: The aim of this @entity1 cadaver study was the determination of intrathecal fluid volume changes during the lumbar flexion and the extension. A special measuring device was designed and built for the study to investigate this issue under controlled conditions. METHODS: The measuring apparatus fixed the lumbar spine firmly and allowed only flexion and extension. The dural sac was closed water tight. The in vitro changes of the intrathecal volumes during the motion cycle were determined according to the principle of communicating vessels. Thirteen @entity1 cadaver spines from the Institute of Anatomy were examined in a test setting with a continuous adjustment of motion. The diagnosis of the @entity2649 was confirmed by a positive computer tomography prior testing. The volume changes during flexion and extension cycles were measured stepwise in a 2 degree distance between 18   flexion and 18   extension. Three complete series of measurements were performed for each cadaver. RESULTS: Two specimens were excluded because of fluid leaks from further investigation. The flexion of the lumbar spine resulted in an intrathecal volume increase. The maximum volume effects were seen in the early flexion positions of 2   and 4  . The spine reclination resulted in a @entity353 . The maximum extension effect was seen between 14   and 16  . CONCLUSION: According to our results, remarkable volume effects were seen in the early movements of the lumbar spine especially for the flexion. The results support the concept of the @entity612 as a dynamic disease and allow a better understanding of the pathophysiology of this nosological entity. Under clinical aspects our data support the value of a body upright position under avoiding of extended spinal inclination and reclination.
