Determination of Predictive Clinical Signs of Effective Rhizolysis Using the DFL Questionnaire. (Rhizolyse)

Determination of Predictive Clinical Signs of Effective Rhizolysis Using the DFL Questionnaire (Diagnosis of Facet Joint Origin Lumbago).

Rhizolysis or lumbar thermocoagulation is a therapeutic proposal for certain types of chronic lower back pain that is resistant to medical treatment and outside the field of surgical indications. A previous study has selected functional and physical signs selected by analysts and a group of experts from the modified "Delphi" prediction method. This study resulted in the creation of a questionnaire (DFL questionnaire) with 16 symptoms: 7 functional and 9 physical. The aim of this new study is to select the symptoms that have the best positive predictive value among the 16 symptoms, to predict a good result of rhizolysis, on the criterion of their mitigation or disappearance in case of effective rhizolysis.

The frequency of chronic lower back pain is a major economic and social problem. Indeed, there are numerous solutions that can be offered to patients, but sometimes they are unsatisfactory as medical treatments are often insufficiently effective, surgical techniques are often invasive and indications can be limited. Rhizolysis or lumbar thermocoagulation is a therapeutic proposal for certain types of chronic lower back pain that is resistant to medical treatment and outside the field of surgical indications. This technique, which is minimally invasive, is low-risk for patients and is widely used. However, few studies have shown its effectiveness, so the level of evidence is not enough to make this technique accepted as a standard. A previous study has selected functional and physical signs for joint involvement in lower back pain. This selection was made by analysts and a group of experts from the modified "Delphi" prediction method. This study resulted in the creation of a questionnaire (DFL questionnaire) with 16 symptoms: 7 functional and 9 physical. The aim of this new study is to select the symptoms that have the best positive predictive value among the 16 symptoms, to predict a good result of rhizolysis, on the criterion of their mitigation or disappearance in case of effective rhizolysis.

Definition of the subgroup of good clinical outcome after rhizolysis (called "effective" rhizolysis) by lumbar VAS or lower extremity pain VAS or Oswestry index decreased at 6 weeks after rhizolysis. The "efficiency" criterion based on the decrease in the dolorimeter or the Oswestry index corresponds to a decrease of at least 50% [1, 2, 3, 4].

• Comparison of the "effective rhizolysis" and "non-effective rhizolysis" subgroups at 6 weeks postoperatively to select the symptoms with the highest positive predictive value among the 16 symptoms of the DFL questionnaire based on the criterion of effectiveness of a decrease of 50% of VAS or Oswestry

Inclusion Criteria: Patient suffering from chronic lower back pain developing for more than 6 months and resistant to the medical treatments. Patients with an indication of lumbar rhizolysis for their chronic lower back pain with a facet component, the starting point of which corresponds to the L4L5 and/or L5S1 stages. Patient not objecting to their participation in the study. Subject registered with a social security scheme Exclusion Criteria: Adults under judicial protection Adult under guardianship or trusteeship Pregnant women Minors