Morphologic changes of lumbar foramen on X-rays in different positions and the relation with percutaneous endoscopic surgery

English Keywords:Lumbar foramen  X-rays  Endoscopic surgery

English Abstract:

  【Abstract】 Objectives: To measure and analyze lumbar foramen parameters on X-rays in natural, extension and flexion positions, and to illustrate the changes of foramen in different positions and its relation with endoscopic surgery. Methods: From December 2014 to October 2015, 100 patients(58 males and 42 females) suffering from low back pain who performed X-ray in our hospital were selected. The height, width of lumbar foramen and the lumbar lordosis were measured on each X-ray in neutral, flexion and extension positions. Based on the lumbar motion changes from neutral to flexion, the patients were diveded into 3 groups(＜10°, 10°-20° and ＞20°). The differences in foramen and vertebrae parameters among positons were analyzed by using one-way ANOVA, Pearson′s correlation coefficients were used to investigate the changes of foramen height and width in different postions and the relationship between these changes and lumbar motion. Results: The average height of lumbar foramen was 20.2±3.7mm(15.0-22.7mm) and the width was 13.7±2.7mm(6.7-10.8mm) in neutral position. The height and width of intervertebral foramen decreased from top to bottom segment of lumbar spine. All lumbar foramen heights and widths decreased in extension compared to neutral position, but there was no statistical significance(P>0.05). The height and width of lumbar foramen in flexion increased significantly compared to neutral and extension positions(P<0.05). In the group of lumbar flexion >20°, foramen heights at all segments except L5/S1 and foramen widths from L2-L5 increased significantly compared to the groups of <10° and 10°-20°(P<0.05). Conclusions: Lumbar foramen heights and widths increase significantly in flexion positions, and widths increase subsequent to the flexion angle increase.