Background and Objectives Medial branch blocks are frequently performed to diagnose lumbar facet-joint–mediated pain. Ultrasound guidance can increase practicability and eliminate exposure to ionizing radiation when compared with fluoroscopy. However, ultrasound-guided L5 dorsal ramus block, which, together with L4 medial branch block is necessary to anesthetize the most commonly affected facet joint L5/S1, has not been described so far. The objective of this study was to develop a technique and to evaluate its accuracy with standard fluoroscopy in unpreselected cadavers.
Methods Twenty ultrasound-guided L5 dorsal ramus block approaches were performed with a new oblique out-of-plane technique in a rotated cross-axis view bilaterally in 10 cadavers. After checking the needle position in a second perpendicular sonographic plane, the final needle position was confirmed with conventional fluoroscopy by an independent observer.
Results All cadavers had significant degenerations of the lumbar spine, and 5 of them had moderate to severe spondylolisthesis. Skin-to-target distances were 42 ±7 mm. Sixteen L5 dorsal ramus block attempts were located at the exact radiological target, 1 was slightly too lateral, and 3 were slightly too caudal (3–10 mm away). The overall success rate in unpreselected cadavers reached 80% (95% confidence interval, 56%–94%) and in the subgroup of corpses without spondylolisthesis 100% (95% confidence interval, 69%–100%).
Conclusions This is the first study to show that ultrasound-guided L5 dorsal ramus block is accurate and feasible in the absence of significant spondylolisthesis when performed with an oblique out-of-plane technique.
Statistics from Altmetric.com
The authors declare no conflict of interest.
GE Healthcare Inc, Europe, provided equipment support for this study. Philip Peng received equipment support from Sonosite Fujifilm Canada. Urs Eichenberger received equipment support from SonoSite Fujifilm Europe and Philips Europe.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.