We propose here to evaluate the precision of lumbar thermocoagulation performed under a transverse ultrasound approach by performing a fluoroscopic control once the needle in the desired position. The effectiveness of the technique will be assessed by measuring different pain and disability scores at six weeks post-thermocoagulation: the Visual analogue pain Scale score (VAS) and the Oswestry disability score (ODI) will be collected, compared to that of the conventional fluoroscopic technique.

Low back pain affects 70 to 80% of people at least once in their lives. They have considerable socio-economic repercussions and represent the leading medical cause of work stoppage, at around 25% .1

The articular pain between the lumbar vertebrae, called facet joints pain, represent between 15 and 45% of all low back pain and their manifestations are grouped under the name of facet syndrome including localized pains at the lumbar level as well as pains referred to the gluteal, trochanteric, inguinal and lateral and posterior region of the thigh. 2-5 The thermocoagulation of the roots innervating the lumbar facets consists in creating a lesion of the nerve roots innervating these articulations in order to block the transmission of the pain.

According to many studies this technique gives good results in 70 to 80% of the cases with an improvement around 71% to more than six months. 6 A recent Meta-analysis involving 454 patients also shows a significant improvement at 12 months of thermocoagulation versus placebo and even versus epidural lumbar. 7

To date, Lumbar Thermocoagulation are still mostly performed under fluoroscopic control by injection of contrast. This technique have proved this effectiveness, but have significant disadvantages, such as the irradiation of the patient as well as that of the practitioner because of the number of daily acts performed and its cost.

For its part, ultrasound is easily available, easy to use, represents a lower cost, and the lack of irradiation. The technique to reach the lumbar facet joints with sonography is pretty well described and known for many years. 8

We propose here to evaluate the precision of lumbar thermocoagulation performed under a transverse ultrasound approach by performing a fluoroscopic control once the needle in the desired position. The effectiveness of the technique will be assessed by measuring different pain and disability scores at six weeks post-thermocoagulation: the Visual analogue pain Scale score (VAS) and the Oswestry disability score (ODI) will be collected, compared to that of the conventional fluoroscopic technique.

Inclusion Criteria:

• Over the age of 18.
• Facet Syndrome.
• Symptomatology superior than 3 mounths.
• A failure of conservative treatement (drugs, physiotherapy...)
• Partial improvement after two lumbar facet infiltrations.

Exclusion Criteria:

• Allergy to any of the constituents of the infiltrated product, or to the contrast medium
• Unstable medical condition: cardiac, respiratory, endocrine (uncontrolled diabetes)
• Local infection (cutaneous, perimedullary / spinal) or systemic.
• Coagulopathy (platelets <50000 / mm3, Prothrombin time <60%, INTernational normalized ratio> 1.5), anticoagulant or antiplatelet therapy treatment other than aspirin.
• Lumbar arthrodesis.
• Neurological condition affecting motor function (Stroke, Parkinson...)
• Pregnant woman.