To assess the efficacy on pain level at 1 month and 12 months of a steroid injection in the inter-vertebral disc for patients with chronic back pain and inflammatory discopathy on magnetic resonance imaging.

Hypothesis: delivering anti-inflammatory drugs in situ may decrease back pain in patients with inflammatory discopathy

Objective: to assess the efficacy on pain level of a steroid injection in the inter-vertebral disc for patients with chronic back pain and MODIC I discopathy on MRI

Methods: a multicenter double blind randomized control trial Setting: 3 tertiary care hospitals in France Patients: 134 patients with disabling chronic low back pain not relieved by usual recommended treatments and MODIC I (inflammatory) discopathy on MRI Intervention: Injection of 25 mg of methylprednisolone in the inter-vertebral disc during a discography (intervention group, 67 patients) or discography alone (control group, 67 patients) Outcome measures: The primary outcome measure is pain level assessed on a 11-point numeric scale (0-100) at 1 month. Success is defined as less than 40 on pain numeric scale at 1 month. Secondary outcome measures are pain level at 12 months, Disability (Quebec questionnaire), quality of life (SF-12) at 1 and 12 months, anxiety and depression (HAD), analgesics and anti-inflammatories during the last week, return to work, assessment of the disabilities at 1 and 12 months and disc inflammation (on MRI) at 12 months. Tolerance and adverse effects will be recorded.

Trial duration: 36 months(24 months for inclusion and 12 months follow-up) Follow-up visits: at 1, 3, 6, and 12 months Statistical analysis: intention to treat

Inclusion criteria :

• More than 18 and less than 70 years old
• Low back pain
• Daily pain for at least 3 months
• Pain level during the last 48 hours > 40 on the numeric pain scale (0-100)
• Lack of efficacy of usual recommended treatments and of other spine steroid injections (epidural or facet joints injections)
• Modic I discopathy on MRI
• Intra-discal injection at least 6 months before inclusion
• Written informed consent
• Social security
• Medical examination

Non inclusion criteria :

• Pregnancy
• Hypersensitivity to methylprednisolone or contrast
• Local or general infection
• Previous disc surgery less than 6 months
• Steroid treatment
• Previous infectious spondylodiscitis
• Ankylosing spondylitis
• Sciatica with neurologic defects
• Uncontrolled psychiatric conditions
• Inability to read or understand French language
• Anti-vitamin K treatments
• Severe coagulation diseases
• Fever > 38 or sedimentation rate > 20
• Discopathy with MODIC 1 signal on several different lumbar stages