科研之友
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摘要
Study Design. A biomechanical calf cadaver study. %26lt;br%26gt;Objective. The purpose of this study was to determine the intradiscal pressure gradient of bridged healthy intervertebral segments in correlation with intraoperative distraction force. %26lt;br%26gt;Summary of Background Data. Bisegmental dorsal stabilization and anatomic reduction is a common treatment option for incomplete burst fractures of the lumbar spine. However, it remains unknown to what extent bridging and intraoperative distraction compromises an intact intervertebral disc. %26lt;br%26gt;Methods. The L2-L3 intervertebral disc level was evaluated in 6 freshly frozen calf cadaver spines. Pressure measurements were obtained with the spine uninstrumented, after dorsal segmental instrumentation from L1 to L3, and after distraction with 400 N and 800 N. Pressure gradient measurements were accomplished with a balloon pressure sensor placed within the nucleus pulposus of the L2-L3 intervertebral disc. Pressure data were recorded by computer data acquisition. Flexion, extension, and lateral bending moments were applied continuously by a testing machine up to a load moment of 7.5 N.m. The pressure gradients were compared with respect to the effects of added instrumentation and distraction. %26lt;br%26gt;Results. After segmental bridging the mean pressure gradients were significantly reduced in all movement directions (P %26lt; 0.001). However, after dorsal stabilization a continuously rising intervertebral disc pressure was recordable. In contrast, no relevant additional reduction of the intradiscal pressure gradient was detectable after applying distraction forces of 400 N or 800 N. %26lt;br%26gt;Conclusion. In a calf model, a distraction force of up to 800 N leads to no additional reduction of the pressure gradient of bridged healthy lumbar segments under flexion and extension moments.
- 出版日期2014-4-1
