Transverse Process and Needles of Medial Branch Block to Facet Joint as Landmarks for Ultrasound- Guided Selective Nerve Root Block

Selective nerve root block (SNRB) has a therapeutic po-tential for lower back pain accompanied by sciatica, and many studies have reported good results.1,2) Furthermore, SNRB can help to confirm the surgical level and range before the operation as a diagnostic tool. It also alleviates pain effectively to delay the operation. However, the tra-ditional method, using computed tomography (CT) or C-Background: Selective lumbar nerve root block (SNRB) is generally accepted as an effective treatment method for back pain with sciatica. However, it requires devices producing radioactive materials such as C-arm fluoroscopy. This study evaluated the useful-ness of the longitudinal view of transverse process and needles for medial branch block as landmarks under ultrasonography. Methods: We performed selective nerve root block for 96 nerve roots in 61 patients under the guidance of ultrasound. A curved probe was used to identify the facet joints and transverse processes. Identifying the lumbar nerve roots under the skin surface and ultrasound landmarks, the cephalad and caudal medial branch blocks were undertaken under the transverse view of sonogram first. A needle for nerve root block was inserted between the two transverse processes under longitudinal view, while estimating the depth with the needle for medial branch block. We then injected 1.0 mL of contrast medium and checked the distribution of th