If the facet joint/ median nerve injections helps for short duration, then the pain doctor might plan for this procedure.
A heat lesion with electrical field is created by the machine to stop the median facet nerve transmitting the pain impulses. The pain doctor will check with different strengths of electric currents to make sure that the needle tip is near the sensory pain causing nerve, but not near the other sensitive structures which can cause weakness. You need to cooperate with the pain doctor during the procedure for this.
This procedure is done as a day case procedure. A venous canula needle is inserted before positioning on table. X-ray is used to direct the needle near the facet nerve. You need to lie on your front for approximately 30-45 minutes. Local anaesthetic is given to skin before the actual spinal needle is inserted.
Instructions to patients: You should be starving for six hours before the procedure, but can drink clear water till 2 hours prior to procedure. Take all your medicines unless instructed otherwise. Once you come to hospital, a nurse will check all details and note it. The pain doctor will explain procedure and get a consent form signed. You should be prepared to stay in hospital atleast till lunch time (may be longer occasionally). You cannot drive or lift anything heavy or hot till midnight. Please arrange for someone to collect you after procedure.
Side-effects: More discomfort for first few days after injection (flare-up pain); infection (rare); bruising at site of injection; weakness of legs due to local anaesthetic (lasts for few hours); risk of nerve damage (1 in 10,000 and can last long); steroid effects (puffiness face, blood sugar changes if diabetic).
Post-procedure instructions: The pain doctor will see you before discharge in the ward. You need to maintain a pain diary after procedure, which will help doctor plan further interventions in future. Take it easy till next day; continue taking your pain killers till you notice any improvement.
Faculty of Pain Medicine guidance leaflet available at Radiofrequency lesion.
Dr Thanthullu Vasu MBBS MD DNB FRCA Dip Pain Mgt FFPMRCA FIPP