Ultrasound-guided LMBB by Caudal-cranial Approach: Radiographic Comparison of a New Ultrasound-guided Method (BLEPAC)

Ultrasound-guided LMBB by Caudal-cranial Approach: Radiographic Comparison of a New Ultrasound-guided Method

Ultrasound-guided Medial Lumbar Bundle Branch Block by Caudal-cranial Approach: Radiographic Comparison of a New Ultrasound-guided Method

The current standard technique is radiography requiring three uni- or bilateral punctures (transverse-axial plane). The ultrasound technique is also described mainly in this plan but a new "caudal-cranial" ultrasound-guided technique was described by Chang et al in 2018 in which the major axis is used to conduct the needle to the desired area. The investigators would like to confirm that this new technique in a single puncture is also possible under ultrasound.

The convex probe is first positioned in the median longitudinal plane opposite the spinous processes of the lower lumbar vertebrae L4 and L5 with the coordinate system on the cranial side and the side opposite the mark on the sacrum side. The latter is visualized as a hyperechogenic continuous line. The probe is then moved away from the midline, the probe is slightly inclined in an oblique paramedian position looking towards the midline, and gradually slid towards laterality in order to reveal successively, the plane of the laminar interlines of the L3, L4 and L5 vertebrae, then the plane of the facelet spacing of these same vertebrae at the junction of the upper and lower articular processes, finally the plane of their transverse processes

the medial branch block on three lumbar levels (L3-L4, L4-L5 and L5-S1) will be performed under ultrasound by "caudal-cranial" approach, followed by an X-ray check to verify the positioning of the needle.

The 22G needle is introduced along a caudal-cranial axis to infiltrate at each level a volume of 1mL of a mixture consisting of 3mL of Linisol 2% (60mg of lidocaine) and 1mL of Depomedrol (Methylprednisolone) 40mg with 1mL of Omnipaque (contrast product). At each level, contrast medium will be injected at the same time as the linisol-depomedrol mixture so that once the BBM under ultrasound is completed, an X-ray check is performed.

The lumbar medial branch block on three lumbar levels (L3-L4, L4-L5 and L5-S1) will be performed by ultrasound-guidance in a longitudinal plane and the correct placement of the needle will be verified by radiography to show if the two modalities are equivalent.

Check the correct placement of the needle placed by caudal-cranial approach by X-ray to show if the placement is correct (at the same time)

Inclusion Criteria: chronic low back pain compatible with facet lumbar syndrome with chronic pain of at least 3 months who have not responded to conservative treatment after at least 4 weeks patients without signs of dissociated pain, radiculitis, neurological diseases including stroke and Parkinson's disease, spinal instability or deformities such as scoliosis, ankylosing spondylitis, history of lumbar surgery, fracture or lumbar tumor Exclusion Criteria: Pregnant or breastfeeding women Allergy to injected products (Depomedrol or Linisol) Psychiatric disorders hindering understanding of the protocol Local or systemic infection Coagulation disorder Obese with a BMI> 35 kg / m²