Magnetic resonance imaging based lumbar interspinous distance measurements in Thai subjects

Abstract

Background : There is no previous report regarding normal lumbar interspinous distance in Thai subjects. The measurement of the lumbar interspinous distance is made based on the magnetic resonance imaging images.

Objective : To measure the distance of the lumbar interspinous process in Thai subjects and compare with the size of the currently available interspinous device in Thai market.

Methods : Sixty healthy subjects (30 males and 30 females) age 20 - 55 years were enrolled into this study. All of the subjects were underwent the lumbar spine magnetic resonance imaging (MRI). The interspinous distance was measured at the most midline cut in T2 weighted MRI image by marking the mid portion of each spinous process from L1 to L5 then the interspinous distance was measured from lower border of proximal spinous process to upper border of adjacent distal spinous process. The measurement was performed at L1-2, L2-3, L3-4 and L4-5 level, respectively then the results were compared with a size of the interspinous device currently available in Thailand.

Results : The mean age of subjects is 36.3 years. Total mean distance from all samples at L1-2 level is 11.8 + 2.3 (10.0 - 14.1) mm, L2-3 level is 10.9 + 2.4 (8.4 - 14.1) mm, L3-4 level is 10.4 + 2.3 (9.0 - 14.1) mm and L4-5 level is 9.9 + 2.2 (8.0 - 13.0) mm. Mean distance in female at L1-2 level is 11.1 + 2.4 (10.0-12.2) mm, L2-3 level is 10.1 + 1.5 (9.2-11.6) mm, L3-4 level is 9.9 + 1.1 (9.1-10.7) mm and L4-5 level is 9.2 + 2.1 (8.0-10.1) mm. Mean distance in male at L1-2 level is 12.5 + 2.1 (10.2 - 14.1) mm, L2-3 level is 11.8 + 3.2 (8.4 - 14.1) mm, L3-4 level is 10.9 + 3.5 (9.0 - 14.1) mm and L4-5 level is 10.6 + 2.2 (8.4 - 13.0) mm. The maximum and the minimum distance from all samples are 14.1 mm and 8 mm respectively which was covered by the range of interspinous device sizes available in Thailand market (range 8 -16 mm) .

Conclusions : This study demonstrated the interspinous distance in Thai subjects. The results provided the important information regarding the proper size of the interspinous device used in Thai individual for surgeon who get involved with interspinous device about a proper range of device size to matching the interspinous distance in Thai population.