Prospective study to analyse pain reduction with two types of canulae and two types of placements for lumbar medial branch radiofrequency denervation.

Patients who suffer from lumbar zygapophyseal joint pain often receive radiofrequency medial branch denervation as treatment. Many types if canulae exist, and many types of placing them in relation to the Medial Branch nerves (MB). The EARL study tries to compare the analgesic effect of thin canulae (22 gauge) placed perpendicular to MB to thicker canulae (18 gauge) placed parallel to MB.

Inclusion Criteria:

• Low back pain of > 3 months
• 18-80 years
• VAS or NRS>6
• Positive controlled block

Exclusion Criteria:

• Pregnancy
• Psichiatric disorders
• Not being able to fulfil questionnaires
• Body Mass Index>35
• Labor Litigation
• Negative or non conclusive controlled block
• Failed Back Surgery Syndrome