Selective nerve root blocks

Nerve root and joint injections are a minimally invasive treatment that helps relieve pain caused by inflammation or compression of nerves in the spine. They are mainly used in cases of radiculopathy, such as sciatica or cervical pain, by injecting cortisone or an anaesthetic close to the nerve root.

What the injections are

These are injections performed with a fine needle, always under fluoroscopic guidance to ensure accuracy so that the substance reaches exactly next to the nerve root. The cortisone reduces swelling and inflammation around the nerve, while the anaesthetic provides immediate relief. Between 1 and 3 repeat sessions may be needed for the best result, with pain relief lasting from a few months to over a year.

When they are needed

They are used for problems such as disc prolapse, spinal canal stenosis or degenerative changes that compress nerves, causing pain in the legs, arms or back. They are also used to relieve arthritic pain (facet blocks). They are ideal before surgery, as part of conservative treatment together with physiotherapy and medication.

How the procedure is done

The patient lies in the prone position, local anaesthesia is administered, and the doctor uses fluoroscopy to guide the needle precisely to the target point where the cocktail of cortisone and anaesthetic is to be delivered. The injection lasts 10–30 minutes, is almost painless, and the patient goes home the same day. Side effects are rare and include temporary weakness in the limbs and numbness, which resolve within 24 hours.

Benefits and limitations

They offer rapid improvement and pain relief, helping to avoid an operation. However, it is important to emphasise that injections relieve pain but do not match the effectiveness of surgery. In other words, injections do not address the underlying primary problem. Nevertheless, in a great many cases they provide sufficient relief and dramatically improve quality of life.

Πηγή φωτογραφίας: Selective nerve root block. Hertfordshire Orthopaedic Specialists. Available at: https://www.hertsortho.co.uk/selective-nerve-root-block-orthopaedic-surgeon-hertfordshire.html (Accessed: 22 December 2025).