Why is local anaesthetic used in a facet joint injection?

Facet joints are small joints at the back of the spine that can contribute to neck or back pain. The anaesthetic acts quickly and can temporarily interrupt pain signals from the treated area. A change in your familiar pain during this window may help the clinician judge whether that joint is involved.

The effect is temporary, so it is not the same as a lasting cure. The injection commonly also contains a steroid intended to reduce inflammation over a longer period. Your response is interpreted with your examination, movement pattern, and other possible pain sources.

Tell the team about allergies, infection, medicines that affect bleeding, diabetes, pregnancy, and previous injection reactions. Follow their directions about medicines, food, transport, and activity. Protect the area while it is numb: avoid heat, heavy lifting, and movements that you would normally stop because pain is temporarily muted.

Write down what changes, when the numbness fades, and which activities remain difficult. Gradual return to normal movement is usually more useful than using early relief to overdo exercise. Keep the follow-up appointment so the response can be reviewed.

Call the treating service if the injection site becomes increasingly red, hot, swollen, painful, or starts draining, or if fever develops. Seek urgent care for new or worsening weakness, loss of bladder or bowel control, numbness around the inner thighs, severe allergic symptoms, or sudden severe spinal pain. Do not wait for a routine review with these warning signs.

Which facet joint is being targeted, and what symptoms support that choice? How long should numbness last? What activity is safe today? What amount of temporary relief would be useful information? When should I review the next treatment or exercise step?