Imaging Measurement Of Anatomical Structures Related To Superior Articular Process Of Lower Lumbar Spine And Its Clinical Significance

Objective:The imaging measurement of the relevant anatomical structures of the upper joint protrusion of the lower lumbar vertebrae in adults provides an anatomical basis for the clinical application of minimally invasive spinal surgery.Methods:Retrospective analysis,from January 2009 to January 2019,patients who had undergone lumbar lateral radiography and CT examination in our hospital,the 300 normal adults were selected according to the standard of nanoarray,the related anatomical structures of the superior articular process of L₄,L₅and S₁were measured by the measuring tool of Pacs system and the measurement results were statistically analyzed and its clinical significance was discussed.Results:1.Results of CT imaging measurement:The grinding width of inner edge of the upper joint protrusion:average measurement data on the left:L₄:5.66±0.65mm,L₅:5.36±0.54mm,S₁:4.66±0.64;average measurement data on the right:L₄:5.62±0.61mm,L₅:5.30±0.57mm,S₁:4.62±0.63mm;The measurement data shows that from L₄to S₁,the distance（width）between the inner edge of the protrusion root of the upper joint protrusion and the vertebral pedicle decreased gradually on axis,and there was no significant differences between the left and right side of the same centrum（P>0.05）.2.The results of imaging examination of lateral films:（1）Length of upper joint protrusions:the average data in measurement are:L₄:13.63±1.25mm,L_5:13.07±1.22mm,S₁:12.68±1.28mm;（2）Removable width of upper joint protrusions:the average data in measurement are:L4:9.59±1.00mm,L₅:8.94±0.98mm,S₁:8.67±0.99mm;The data shows that from L₄to S₁,the width between the length and removable width of upper joint protrusions are gradually reduced on the lumbar vertebrae view,and the differences between different centrums are statistically significant（P<0.05）.（3）The width of the lower half of the intervertebral foramina:the average measurement data are:L₄:9.45±0.85mm,L₅:8.45±1.17mm,S₁:7.49±1.23mm;（4）The height of the lower half of the intervertebral foramina:the average measurement data are:L₄:5.18±0.87mm,L₅:4.61±0.81mm,S₁:3.10±0.93mm;The width and height of the lower half of the vertebral foramina from L₄to S₁decreased gradually on the lumbar lateral view,and the difference between the different sections was statistically significant（P<0.05）.（5）The area of the lower half of the intervertebral foramina:the average measurement data:L₄:42.59±8.78mm²,L₅:33.97±7.69mm²,S₁:27.69±7.51mm²;（6）The removable area of upper joint protrusions:the average measurement data:L₄:45.89±8.71mm²,L₅:42.16±7.86mm²,S₁:39.42±7.79mm²;The area of the lower half of the intervertebral foramina and that of the upper joint protrusions on the lumbar lateral view from L₄to S₁were gradually reduced,and the differences between the different sections was statistically significant（P<0.05）.Conclusion:1.When spinal endoscopes approach into the lower lumbar intervertebral foramina,the removal of the ventral upper joint protrusion by 39.42±7.79mm² will not damage the stability of the spine;2.When spinal endoscopes approach into the lower lumbar intervertebral disk,the removal of the medial edge of the upper joint protrusions by 4.64±0.63mm can fully expose the lateral recess and the medial edge of the pedicle without destroying the stability of the spine;3.The lower part of the intervertebral foramen of the lower lumbar vertebra cannot pass through the working cannula with a diameter of 7.5mm.