Johnsson R, Axelsson P, Gunnarsson G, Strömqvist B
Department of Orthopedics, Lund University Hospital, Sweden.
Spine (Phila Pa 1976). 1999 Apr 1;24(7):687-90. doi: 10.1097/00007632-199904010-00014.
An evaluation of the intervertebral stability of transpedicular instrumentation in posterolateral lumbar fusions by roentgen stereophotogrammetric analysis.
To determine the in vivo intervertebral stability of posterolateral lumbar fusions augmented with transpedicular screws and plates.
Transpedicular bone screw systems have been found to be as safe and clinically effective as other types of devices in stabilizing surgery of the spine. Many experimental studies have yielded basic data on the stabilizing implant effect in vitro, but the exact in vivo stabilizing effect on human lumbar vertebrae has not been presented previously.
In 12 patients, the intervertebral stability of posterolateral fusion in the lower lumbar spine augmented with transpedicular screws and plates was evaluated by serial roentgen stereophotogrammetric analysis with the patients in supine and erect positions 1 year after surgery.
Screws in each fused vertebra yielded stable fixation or permitted sagittal intervertebral translations smaller than 1 mm induced by the positional change. A widely decompressed and destabilized vertebra without screw fixation yielded persisting intervertebral translations.
The current study demonstrated the adequacy of in vivo stability of lumbar fusions augmented with transpedicular screws and plates. Sagittal translation seems easier to elicit than movements along the other three-dimensional axes. A widely decompressed and destabilized vertebra without screw fixation increases the risk for persisting intervertebral translations. The roentgen stereophotogrammetric analysis technique described seems to be a good way of comparing the in vivo behavior of different implant systems.
通过X线立体摄影测量分析评估腰椎后外侧融合术中经椎弓根器械固定的椎间稳定性。
确定经椎弓根螺钉和钢板增强的腰椎后外侧融合术在体内的椎间稳定性。
在脊柱稳定手术中，经椎弓根骨螺钉系统已被证明与其他类型的器械一样安全且临床有效。许多实验研究已得出体外稳定植入物效果的基础数据，但此前尚未报道其对人体腰椎的确切体内稳定效果。
对12例患者在术后1年通过连续X线立体摄影测量分析评估下腰椎经椎弓根螺钉和钢板增强的后外侧融合术的椎间稳定性，患者分别处于仰卧位和直立位。
每个融合椎体内的螺钉产生稳定固定，或允许因体位改变引起的矢状面椎间移位小于1毫米。一个广泛减压且失稳但未用螺钉固定的椎体产生持续的椎间移位。
本研究证明了经椎弓根螺钉和钢板增强的腰椎融合术在体内稳定性的充分性。矢状面移位似乎比沿其他三维轴的运动更容易引发。一个广泛减压且失稳但未用螺钉固定的椎体增加了持续椎间移位的风险。所描述的X线立体摄影测量分析技术似乎是比较不同植入系统体内行为的好方法。
