Radiofrequency neurotomy (RFN) is a well established treatment for facet joint pain, which has been previously diagnosed where appropriate with a diagnostic medial branch block.^2;5;8 Sometimes facet joint injection is used as a surrogate for the diagnostic component of the test. The principle is that when local anaesthetic is placed either in the joint or adjacent to the nerve supply of the joint, pain from the joint should be eliminated for the duration of this anaesthetic (usually 1-6 hours).

The medial branches are nerves that arise from the dorsal rami, which in turn arise from the spinal nerve at each vertebral level. They innervate the facet joints as well as some of the smaller posterior para-vertebral muscles (multifidus). Medial branch blocks have been shown to be an effective predictor of the likely success of a RFN procedure.

This is a highly targeted injection directed at the specific nerve root that is compromised by a disc prolapse and is causing radicular pain (sciatica). It has the highest efficacy of all forms of epidurals for this type of pain.

Transforaminal epidural injections are the same as transforaminal nerve root injections. In a transforaminal injection (TFI) a needle is placed into the foramen through which a spinal nerve root emerges from the spine. A foramen in this instance is an opening between adjacent vertebrae. These spinal nerves often join to form other nerves, such as the sciatic nerve.  Thus, the procedure is transforaminal (across or through the foramen).

Epidural injections have been used in the treatment of radicular pain for about 90 years.  Recent studies on epidural injections have largely been confined to those performed via the transforaminal route. A caudal epidural is the infiltration of material through a needle placed into the epidural space through an opening just above the coccyx called the sacral hiatus.

Epidural injections are mainly known as an injection for pain relief during childbirth, where the effect is only for a fairly short period.  In contrast, epidurals are used in back problems in an attempt to produce long term relief.  This may be because corticosteroids are added to the local anaesthetic solution.

Pulsed radiofrequency neurotomy (PRFN) is a technique where nerves are minimally heated to 42 degrees centigrade in order to relieve pain. 

Technical information