Lower back pain treatment. Frontal X-ray showing a close-up of the lower backbone (down left) of a 62-year-old with lower back pain. The pain is being treated by using a needle (right) to inject hydrocortisone. The injection site is located next to the foramen (nerve opening) at the L4-L5 vertebral junction, near the nerve root. The first injection is of a contrast medium to highlight the area being treated, and the second injection is of hydrocortisone to treat inflammation in this region.