Dad had an epidural steroid injection into his sacral spine for a pinched nerve. The surgeon told us that he was unable to get the injection into the right spot so he wasn't sure it would work. Where does the drug go when it's injected into the wrong spot?
When low back pain is caused by a pinched or compressed nerve in the sacral area, a steroid injection into the spinal canal can provide welcome relief. But it's a tough area to gain access and the chances are high that the surgeon can miss the right spot. That's been proven over and over in trials conducted by experienced and confident physicians.
When injecting the sacral area, the injection must slip into the sacral hiatus, a tiny opening in the middle of the sacrum. The sacrum is a pie-shaped or wedge-shaped bone that sits at the end of the lumbar spine just above your coccyx (tailbone).
The sacral hiatus is further identified by two bony bumps called the sacral cornua that run along each side of the hiatus. Getting the injected fluid through the hiatal hole and into the spinal canal may improve the accuracy of this treatment approach. Missing the mark doesn't always hurt the patient -- it usually just means the injected fluid goes into the soft tissue surrounding the sacrum. When injected into that spot, it's not very helpful either.
Researchers are experimenting with ultrasound as a way to screen patients before attempting epidural steroid injections into the sacral area. A special new type of 3-D, real-time ultrasonography is now available making it possible to conduct this type of pretreatment test. Accuracy of injection was improved significantly in a trial conducted on 47 patients with low back pain in need of an epidural injection. The success rate wasn't 100 per cent, but it was much higher than in previous studies conducted without ultrasound screening.