Ultrasound-guided Lumbar Periradicular Injection: Effectiveness and Benefits of a Non Irradiating Infiltration Technique. A Randomized Controlled Trial

Foraminal periradicular infiltrations for therapeutic purposes are currently recognized as an integral part of the treatment of radiculalgia, particularly in case of radiculalgia refractory to a well-conducted initial treatment, in combination with the rehabilitation and education of the patient. The incidence of low back pain, lumbar pain or pure radiculalgia in the general population is very high. In fact, the majority of people will experience at least once in their life low back pain or neck pain, favored by the growing aging of the population. This leads us to propose infiltrative techniques more and more modern, as much in the technique performed as in the type of medication used, presenting the best risk / benefit ratio. Infiltrations guided by imaging tend to become less and less "invasive", with the undeniable contribution of ultrasound as a major tool in the diagnostic and therapeutic approaches, both in specialized pain management clinic as in other medical specialties. To date, infiltrations are still mostly performed under fluoroscopic control by injection of contrast medium (epidurography), or under CT control, where the identification of the anatomical structures and therefore the target allows a greater accuracy of the level of infiltration. These two techniques have proven their 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; their cost, and the need for a radiologist in the case of a CT technique. For its part, ultrasound is easily available, easy to use, represents a lower cost, and the lack of irradiation.

In recent years ultrasound has proved effective in identifying anatomical structures of the spine and in the techniques of lumbar periradicular infiltration, whether performed in sagittal paramedian or oblique sagittal paramedian, the latter having shown a better intra-foraminal distribution of the injected product. (39.5% vs 87.5% in terms of intraforaminal diffusion of the contrast medium). In addition, teams have shown the superiority of ultrasound-guided lumbar foraminal infiltration compared with CT control in terms of time spent on infiltration, for exact accuracy in 90% of patients, and an improvement in radiculalgia at 1 month similar between the two techniques.

We propose here to evaluate the precision of lumbar periradicular infiltration 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 four weeks post-infiltration: the Visual analogue pain scale score, the DN4 score, and the Oswestry disability score (ODI); The decrease in irradiation received will be collected, compared to that of the conventional fluoroscopic technique.