Facet joint injection
This is an injection into the facet joint (see ‘The normal Structure of the Spine’) It can be given in the neck and lower back. and should always be give under x-ray control to ensure optimal placement of the needle. Some doctors administer a small does of contrast to see whether this fills the joint. The facet joins are on either side of the spine and in the majority of cases injections are give to both joints of a level. It is often difficult to say exactly which facet joint is causing the pain. Therefore most doctors will inject two or three levels at the same time.
The main indication is low back pain due to facet joint arthritis. This should be carefully assessed and the injection should not be given just for low back pain. The effect can last several months. In some cases a facet joint injection can be helpful in finding the source for the pain or knowing the exact level. This can be a useful tool before a spinal fusion if it is clinically or radiologically not clear which level is mainly causing the pain.
Complications are very uncommon if guided by x-rays but the degree of pain relief various a lot.
Discography or intra-discal injection
This is an injection directly into the intervertebral disc with local anaesthetic. It is usually given for diagnostic purposes before a spinal fusion or disc replacement. The aim is to reproduce the pain the patient is complaining about to identify the correct level. Usually a ‘healthy’ level is also injected as a test. This injection can only be given under x-ray or CT control. In my opinion, it should not be given as a treatment for patients with low back pain. For complications see epidural injection. In addition a direct nerve root injury from the needle is possible leading to numbness, paralysis or chronic nerve pain.
This injection is given if the sacro-iliac joint (this is the joint connecting the base of the spine to the pelvis) is the source of the pain.
CT/x-ray guided nerve root block
This injection can be done for treatment or diagnostic purpose. If it is clinically and radiologically (on MRI) clear that one specific nerve is causing the pain a targeted root block is indicated. In contrast to epidural injections it will have no effect on any other nerve. Sometimes it is not clear, which nerve root is causing the pain in particular if there is nerve entrapment at different levels. A root block can help to identify the correct level. Obviously, only one level should be done at a time.
Lumbar puncture/ lumbar drain
A lumbar puncture involves aspiration of cerebrospinal fluid through a needle. It is usually done in the lumbar spine. As the cerebrospinal fluid is flowing freely between the brain and the spine it is a common diagnostic procedure for suspected infections (meningitis) or a certain type of brain haemorrhage (subarachnoid haemorrhage). It is also used to investigate other neurological conditions. Initially, some local anaesthetic is administred to numb the skin. The needle is inserted in the midline of the spine until CSF starts draining. This injection normally does not require x-ray control unless it is not possible to drain CSF. In rare cases, drugs can be administered. One side effect is low pressure headach due to continuous leakage of CSF into the epidural space after the needle is withdrawn.
Through a lumbar drain, CSF can be drained for a more prolonged period of time. This is done for diagnostic purposes (for possible normal pressure hydrocephalus) or as treatment for CSF leaks after surgery.