A spinal bone
The epidural space is the area between the bone and the dura (the thin layer of tissue that encloses the nerves within the spinal canal)
An epidural injection usually consists of a steroid solution mixed with some saline and local anaesthetic.
The purpose of the injection is to deliver this anti inflammatory mixture to the area that is responsible for a patients sciatica.
The hope is that the procedure will lead to at least a partial resolution of symptoms.
The results of epidurals are variable.
Some patients describe a complete resolution of symptoms, others, sadly, tell me that it hasn't helped.
Sometimes epidurals work well for a period and then the pain comes back.
If the first injection has helped, it is sometimes worth trying a second injection.
They are usually administered with the patient sedated by an anaesthetist, that way they are not a painful experience.
Patients go home the same day but cannot drive themselves after having had sedation.
Complications are rare but need to be considered.
I always warn patients that there is a small risk of infection, bleeding and csf leak.
Generally, the risks of epidural are less than the risks of surgery, which may be the only viable alternative for some patients.
Epidurals are used to treat nerve pain associated with slipped disc and spinal stenosis