Radiologic analysis and clinical study of the upper one-third joint technique for fluoroscopically guided sacroiliac joint injection

Background: sacroiliac intraarticular injection by the traditional technique can be challengingto perform when the joint is covered with osteophytes or is extremely narrow.objective: to examine whether there is enough space for the needle to be advanced fromthe l5-s1 interspinous space to the upper one-third sacroiliac joint (sij) by magnetic resonanceimage (mri) analysis as an alternative to fluoroscopically guided sij injection with the lowerone-third joint technique,and to determine the feasibility of this novel technique in clinicalpractice.study design: mri analysis and observational study.setting: an interventional pain management practice at a university hospital.methods: we analyzed 200 axial t2-weighted mris between the l5 and s1 vertebrae of100 consecutive patients. the following measurements were obtained on both sides: 1) thethickness of fat in the midline; 2) the distance between the midline (point c) and the junction(point a) of the skin and the imaginary line that connects the sij and the most medial cortexof the ilium; 3) the distance between the midline (point c) and the junction (point b) of theskin and the imaginary line that connects the sij and the l5 spinous process; 4) the distancebetween the sij and midline (point c) on the skin,or between the sij and the midpoint(point c’) of the line from point a to point b; and 5) the angle between the sagittal line andthe imaginary line that connects the sij and the midline on the skin. the upper one-thirdjoint technique was performed to establish the feasibility of the alternative technique in 20patients who had unsuccessful sacroiliac intraarticular injections using the lower one-thirdjoint technique.results: the mean distances from the midline to point a and to point b were 21.9 ± 13.7 mmand 27.8 ± 13.6 mm,respectively. the mean distance between the sij and point c (or point c’)was 81.0 ± 13.3 mm. the angle between the sagittal line and the imaginary line that connectsthe sij and the midline on the skin was 42.8 ± 5.1°. the success rate of sacroiliac intraarticularinjections with the upper one-third joint technique was 90% (18/20).limitations: this was an observational study and lacked a control group.conclusions: sacroiliac intraarticular injections with the upper one-third joint technique areadvisable when it is hard to perform them with the lower one-third joint technique. © 2015,american society of interventional pain physicians. all rights reserved.