US-guided and FS-guided infiltrations
TUNNEL VISION, LORDOSIS, INFILTRATION
Patients were positioned in prone position with a pillow under the stomach to facilitate the view of the structures by compensating the lumbar lordosis. After disinfection of the lumbo-sacral region with alcoholic chlorhexidine 0,5%, an infiltration was performed in three puncture points unilaterally (L3-L4, L4-L5 and L5-S1 levels) with a 22-gauge spinal needle in the transverse plane. At each level, 1 mL of a mixture consisting of 3 mL of Linisol 2% (60 mg of lidocaine) plus 1 mL of Depomedrol 40 mg/Lidocaine 10 mg was injected. The procedure time was recorded from insertion to removal of the needle. The ultrasound devices used were different between the centers; C6–2 probe of the Sparq ultrasound system (Philips N.V., Netherlands) at César de Paepe Hospital, C1–5 probe of the Logiq S8 ultrasound system (GE Healthcare Inc., Illinois, United States) at Erasme and Braine-l’Alleud Hospital. The scopies used were also different; Ziehm brand (Ziehm Inc., Florida, United States) at César de Paepe and Siemens brand (Siemens Healthcare Gmbh, Germany) at Erasme and Braine-l’Alleud Hospitals. It should be noted that thermocoagulation was performed after 2 weeks on patients at the Braine-l’Alleud hospital.In the US group, once the spinous processes of the lower lumbar vertebrae were located, with a convex probe with the mark on the cranial side (Fig. Firstly, the probe was placed longitudinally in order to have the facet paramedian sagittal view (wave image). Secondly, a rotation of 90° was made to be in the transverse planeIn the FS group, The C-shaped arm of a X-ray fluoroscopy was positioned around the patient in an antero-posterior view tilted ¾ in order to see the classic view called “scotty dog”. The puncture point was determined by the positioning of the needle with the so-called “tunnel vision”. The needle was thus brought to the bone contact corresponding to the eye of the scotty dog in tunnel vision, corresponding to the area of passage of the lumbar median branch.