CT-guided obturator nerve block for diagnosis and treatment of painful conditions of the hip

Obturator nerve blocks (ONB) have been performed by anaesthesiologists main ly to eliminate the obturator reflex during transurethral resections. An ef fect on hip pain has also been described. However, being a time-consuming a nd operator-dependent procedure if performed manually, it has not been wide ly used for chronic hip pain. The purpose of this pilot study was to check whether CT guidance could improve reproducibility of the block (= immediate effect) and to test its potential value for treatment of chronic hip pain. Fifteen chronically ill patients with osteoarthritis underwent a single ON E. Sixteen millilitres of Lidocaine 1% mixed with 2 ml Iopramide was inject ed into the obturator canal. The patients were followed up to 9 months afte r the intervention. With a single injection pain relief was achieved for 1- 8 weeks in 7 of 15 patients. Excellent pain relief for 3-11 months was achi eved in another 4 patients. Reasons for a midterm or even long-term effect based on a single injection of local anaesthetic are not exactly known. The CT-guided ONE is a fast, easy and safe procedure that may be useful for mi d-term (weeks) and sometimes even long-term (months) treatment of hip pain.