The purpose of this study is to evaluate the effectiveness of facet joint infiltration with corticosteroids in the treatment of low back pain due to facet joint osteoarthritis.

Sixty subjects with diagnostic of facet joint syndrome will be enrolled in the study.

They were randomized into experimental and control groups. The experimental group will be submitted to intra-articular infiltration of six facet joints. The control group will be submitted to intramuscular injection of six lumbar paravertebral points. After the randomization, all subjects will be assessed by an investigator blinded to the groups. The assessment will be taken just before the interventions (T0) and them 7 , 30 , 90 and 180 days after the interventions. The following assessment instruments will be used: pain visual analogical scale (VAS) (0-10cm), pain visual analogical scale during extension of the spine (VAS E) (0-10cm), Likert scale for improving (0-5), percentage scale of subjective improving perception(0-100%), Rolland-Morris questionnaire (0-24), short health survey questionnaire (SF36), accountability of medications taken for back pain: analgesics and non-steroidal antiinflammatories (NSAIDs).

Inclusion Criteria:

• low back pain up to 3 months
• pain on back extension
• radiologic findings of facet joint osteoarthritis

Exclusion Criteria:

• other causes of back pain
• fibromyalgia
• diabetes, arterial hypertension or glaucoma not well controlled
• patients with contrast allergy