This procedure is done under local anaesthesia, with the patient sedated and lying face down. It aims to relieve low back pain and sciatica by delivering heat energy to the damaged disc annulus. This stiffens the annulus and reduces the sensation of pain from nerves within it.
The damaged disc is identified by injecting contrast fluid into it, to check it is causing the symptoms (known as lumbar discography). One or 2 needles are inserted into the disc annulus using X‑ray guidance. A thin flexible tube (electrode) is then passed through the needle and into the side of the disc. Once in position the damaged disc annulus is slowly heated with the electrode, usually for about 2–15 minutes, before the electrode is removed.