In spite that variable techniques for lumbar MBRF exists, the tunnel vision technique is widely recommended for exact radiofrequency needle placement. However, this method uses the concept of a steep caudocephalad axial tilt of the fluoroscopy beam, which result in unusual appearance of vertebral structures and a long distance from skin to the target site. In our institution, therefore, the investigators have used a modified method that is easy and safe to place RF needle parallel to the lumbar medial branch in oblique fluoroscopic view.

Accordingly, our objectives were to evaluate our modified technique for lumbar MBRF, comparing with the tunnel vision technique, and additionally to assess complications with respect to these two techniques.

The zygapophysial (facet) joint pain has been a challenging condition for pain specialists since the 20th century. According to the previous reports, degenerative changes of facet joint account for 10% - 15% of the cases with chronic low back pain. However, it is a major source of frustration that there is no definitive standard to document a clinical diagnosis and few validated treatment about lumbar facet joint pain.

Although it has been a subject of debate how best to select patients, radiofrequency (RF) neurotomy is frequently performed procedure for patients with lumbar facet generated pain. Lumbar medial branch radiofrequency (MBRF) is assumed to be effective and safe treatment for lumbar facet joint pain with 1.0% rate of minor complications per lesion site. The rationale and efficacy of lumbar MBRF would depend on the use of meticulous radiofrequency (RF) needle placement with stringent patient selection.

In spite that variable techniques for lumbar MBRF exists, the tunnel vision technique is widely recommended for exact RF needle placement. However, this method uses the concept of a steep caudocephalad axial tilt of the fluoroscopy beam, which result in unusual appearance of vertebral structures and a long distance from skin to the target site. In our institution, therefore, the investigators have used a modified method that is easy and safe to place RF needle parallel to the lumbar medial branch in oblique fluoroscopic view.

Accordingly, our objectives were to evaluate our modified technique for lumbar MBRF, comparing with the tunnel vision technique, and additionally to assess complications with respect to these two techniques.

Inclusion Criteria:

- Chronic low back pain patients (pain duration > 6 months) who had not responded to previous treatment, underwent screening medial branch blocks (MBBs) using 0.5% levobupivacaine hydrochloride (Chirocaine®, Abbott Korea Ltd, Seoul, Republic of Korea) 0.5 mL at each of the standard target points.8 Patients that achieved at least 80% pain relief by screening MBBs underwent controlled comparative local anesthetic blocks using 1% lidocaine (0.5 mL) and 0.5% levobupivacaine (0.5 mL). Those that achieved greater than 80% pain relief following double blocks were eligible for lumbar MBRF, but those with prolonged responses to screening or dual-controlled comparative MBBs were not considered eligible.

Exclusion Criteria:

1. Duration of low back pain < 6 mo
2. Single diagnostic block
3. Prolonged responses to screening or dual-controlled comparative MBBs
4. Discogenic pain verified by controlled discography
5. Evidence of radiculopathy, as determined by history, physical examination, and radiologic studies
6. Structural lumbar spinal deformity
7. Rapidly worsening pain, numbness, weakness, hyperreflexia, changes in bladder function, and other neurological symptoms which should prompt a reevaluation and surgical evaluation.
8. Previous back surgery
9. Severe psychiatric illness