Why have a spinal injection?
Spinal injections are performed as a treatment, to reduce pain and inflammation within the spine, as a well as a diagnostic tool to confirm a suspected cause of the symptoms, therefore allowing appropriate planning of further treatment.
Injections can be used to treat pain within the arms or legs due to nerve root compression, or pain within the neck or back, which may be arising from either the degenerative facet joints or the degenerative intervertebral discs.
The procedures involve the injection of local anaesthetic and steroid into the area of the spine, which is causing the problem. The local anaesthetic gives immediate, but short lasting pain relief from half to several hours. The steroid is an anti-inflammatory drug which reduces swelling and may take several days to have its full effect.
How are these performed?
The procedures are performed within an operating theatre using sedation and local anaesthetic for pain relief and an X-ray machine (Image Intensifier (IT)) is used to ensure the correct placement of the needle within the spine. The injection may also require the use of a special dye, which is visible on the IT.The type of injection performed depends upon the predominant symptom which needs to be treated.
Complications are very rare, but as the needle is near the nerves and spinal cord, complications include infection, bleeding, transient weakness and numbness in the limbs, leakage of the Cerebrospinal fluid that can lead to headache and photophobia and anaphylactic or allergic reaction due to the anaesthetic or steroid.
Nerve Root Sleeve Injections or blocks (NRSI)
NRSI is an injection around a nerve root which can be used for therapeutic and diagnostic purposes.
Therapeutically, it relieves the leg or arm pain produced by pressure on a nerve root, usually caused by a disc prolapse, but may be due to bone compressing the nerve or other rare causes.
Diagnostically, the root block helps determine which area within the spine is the cause of the problem. This can be extremely useful when surgery is being planned.
The epidural space surrounds the spinal nerves but still within the central spinal canal. The needle is placed within this space and is similar to a NRSI, but treats several nerves. This is beneficial if several areas are affected, but does not have the same diagnostic ability as a NRSI.
Facet Joint Injections
The facet joints are positioned at the back of the spine in pairs, connecting two adjacent vertebrae. They movewhen the spine and the intervertebral disc move. Theymay become degenerate or arthritic, which may then become a source of back pain. Facet joint injections are used diagnostically to determine if they are the source of pain and therapeutically to reduce the inflammation.