Study on the Efficacy of Infiltration of Upper Cluneal Nerves in Chronic Pain Related to Cluneal Syndrome

Study Overview
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Brief Summary
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Lower back pain is a very common complaint in the Chronic Pain Clinic. Its etiology is nonspecific in 85% of the cases. In 1957, Strong and Davila reported that the superior cluneal nerves (SCNs) and middle cluneal nerves (MCNs) can be entrapped around the iliac crest, suggesting a causal relationship between this entrapment (SCN-Entrapment, SCN-E) and low back pain symptom. This is known today as cluneal syndrome. Cluneal syndrome remains poorly investigated and is currently a diagnostic challenge. Various types of lumbar movements exacerbate its occurence. The most common theory regarding the origin of this pain evokes that is primarily due to a mechanical cause linked to stenosis or adhesions of fibrous tissue around the cluneal nerves causing distress. The hypothesis is that the investigator can reduce the pain related to the syndrome of superior cluneal origin thanks to a volume effect which aims to detach adhesions and/or aponeurotic stenoses that cause a distress of cluneal nerves. The aim of this study is to assess the effectiveness of the cluneal nerve block using theThomas Dahl Nielsen ultrasound based technique in patients with chronic low-back pain related to SCN-E. To this end, the investigator will compare physiological serum injection versus local anaesthetic injection, with the aim of reducing short-term pain and improving quality of life.

Official Title
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Study on the Efficacy of Infiltration of Upper Cluneal Nerves in Chronic Pain Related to Cluneal Syndrome

Conditions
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Cluneal Syndrome, Nerve Entrapment Syndrome

Intervention / Treatment
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* Drug: Ropivacaine injection
* Drug: Physiological serum injection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient signed Inform Consent Patient diagnosed with unilateral or bilateral superior cluneal syndrome : Diagnostic points will be : a maximum pain at the trigger point on the back iliac crest, approximately 7 cm from the median line and 4.5 cm from the poster superior iliac crest. Palpation on this point causes pain reminding the patient's long-term pain), Palpation rolled-palpated at the buttocks provokes either pain, paraesthesia, or discomfort. The criteria of facial syndrome, sacro-iliac syndrome or radiculopathy are excluded. Low back pain during back movements. Exclusion Criteria: Pain not associated to superior cluneal syndrome. Infection at the puncture point. Pain of suspected neoplastic origin. Allergy to local anaesthetics. Refusal of the patient

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Physiological serum Group<br>The cluneal nerve block is performed under ultrasound using the Thomas Dahl Nielsen and Thomas Fichtner Bendtsen method. The patients are placed in ventral decubitus. A sensor of high linear frequency is moved toward the middle and posterior to where the aponeurosis of the transverse muscle and the thoraco-lumbar fascia meet, following the appearance of the thoracolumbar fascia and then the appearance of the posterior ilio-costalis muscle under the fascia lumbar area. The infiltration is carried out in-plane, with a lateral towards the median axis direction, in a way, that it penetrates perpendicularly the fascia The physiological serum (NaCl 0.9%) will be injected, on each side, into the aponeurosis and the muscle in the area where the superior cluneal nerves pass. An easy separation of the thoraco- lumbar fascia and the ilio-costalis muscle is achieved during injection by slightly raising the needle towards the median axis as the space opens up gradually. | Drug: Physiological serum injection<br>* The patients will receive 15 ml of physiological serum (NaCl 0.9 %) on each side.<br>|
| Experimental: Ropivacaine Group<br>The cluneal nerve block is performed under ultrasound using the Thomas Dahl Nielsen and Thomas Fichtner Bendtsen method. The patients are placed in ventral decubitus. A sensor of high linear frequency is moved toward the middle and posterior to where the aponeurosis of the transverse muscle and the thoraco-lumbar fascia meet, following the appearance of the thoracolumbar fascia and then the appearance of the posterior ilio-costalis muscle under the fascia lumbar area. The infiltration is carried out in-plane, with a lateral towards the median axis direction, in a way, that it penetrates perpendicularly the fascia The local anaesthetic (Ropivacaine) will be injected into the aponeurosis and the muscle in the area where the superior cluneal nerves pass. An easy separation of the thoraco- lumbar fascia and the ilio-costalis muscle is achieved during injection by slightly raising the needle towards the median axis as the space opens up gradually. | Drug: Ropivacaine injection<br>* The patients will receive 15 ml of Ropivacaine 0.375 % on each side.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of pain intensity in the acute phase of the treatment. | The pain intensity will be assessed using the numeric analogue scale (NAS) at 5 minutes, 30 minutes, 60 minutes and will be compared with (the pain intensity at) the baseline. The patient rate the pain from 0 to 10 (0 = no pain; 10 = worst pain imaginable) | up to 1 hour post-infiltration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of pain in the late phase of the treatment. | The pain intensity will be assessed with the numeric analogue scale (NAS) at 15 days, 1 month, 3 month post-infiltration and will be compared with the pain intensity at the baseline. The patient rate the pain from 0 to 10 (0 = no pain; 10 = worst pain imaginable) | up to 3 months post-infiltration | 
| Impact of Pain on daily life | Impact of pain on daily life will be evaluated according to the Dallas Pain Questionnaire (DPQ). The Dallas Pain Questionnaire (DPQ) is 16-item visual analog tool for evaluating how the chronic pain affects the daily activities (The higher the score, the greater the impact of low back pain on quality of life). The impact on daily life will be evaluated before infiltration, 15 days, 1 month, 3 months after infiltration. | up to 3 months post-infiltration | 
| Incidence of Side effects | Side effects will be collected such that the intolerance to the technique and/or injected product, traumatic complications | up to 3 months post-infiltration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Superior cluneal nerve entrapment, Chronic Low-back Pain, Injection Site Infiltration, Local anesthetic, Pain, Cluneal nerve block