Available in Brazil
Procedures will be performed in the surgical block of Hospital SARAH, Brasília unit, using an
aseptic technique.
All participants will undergo sedation or general anesthesia using a laryngeal mask airway,
according to the preference of the anesthetist in the room. The procedure will be performed
with the participant positioned in dorsal decubitus, on a radiolucent table, with a small
pillow below the knees to promote a slight flexion of 10 to 20 degrees of the hips, leading
to relaxation of the joint capsule.
The surgeon will be positioned at the side of the surgical table, facing the affected hip,
with the scoping device on the contralateral side, aligned at 90 degrees with the patient,
allowing the visualization of anteroposterior images of the affected hip.
For the control group (IAI), a 22G spinal needle will be used, positioned in the
anteroposterior direction towards the central portion of the femoral neck, which will be
introduced until it trespasses the anterior hip capsule through tactile sensitivity. After
verifying the correct positioning with the use of fluoroscopy and infusion of 3 milliliters
(ml) of iodinated contrast diluted at 50% (Iomeron® 300, Patheon Italia S.p.A. Ferentino -
Italy), an infiltration of 4 ml of 1% Ropivacaine (Ropi®, Cristália, Itapira - São Paulo,
Brazil) and 80mg of methylprednisolone 40mg/ml (Predi-Medrol®, União Química, Brasília -
Federal District, Brazil) will be performed, totalizing 6 ml of solution.
In the intervention group (IA + CRF), radiofrequency ablation will be performed with the aid
of a 22-gauge cannula (Diros Technology Inc, Markham, Ontario, Canada), 10 or 15 cm long,
with a 10-mm curved active tip, at a temperature of 90º for 90 seconds. The cannula will be
introduced in the region just above the tip of the greater trochanter, lateral to a
descending line originating in the anterior superior iliac spine (ASIS), and directed to the
medial border of the patella (ASIS - patella). Its introduction will take place in the
anteroposterior and lateromedial direction, to reach the region lateral to the anatomical
reference known as the teardrop, with an angle of about 20 to 30 craniocaudal degrees about a
transverse line on the axis of the thigh. The denervation of the articular branches of the
Obturator Nerve (NO) will be performed in 2 cycles, at a temperature of 90 degrees for 90
seconds, starting lateral to the lateral edge of the obturator foramen and inferior to the
teardrop, with subsequent repositioning of the cannula about 1 cm lateral to the first point.
Both lesions will be preceded by motor stimulation at 2.5 volts (V) to exclude motor branches
within the range of action of the active tip followed by the infusion of 2ml of 1%
ropivacaine. Then, the cannula will be repositioned in a more cranial location, 2 to 3 cm
lateral to the ASIS-patella line, parallel to the superolateral edge of the acetabular dome,
to reach the sensory branches of the Femoral Nerve (NF), performing three cycles (from medial
to lateral) at the 01, 12, and 11 o'clock positions. The most medial lesion will be preceded
by motor stimulation at 2.5 V to exclude motor branches within the active tip's range of
action. All three cycles will be followed by 2 ml of 1% ropivacaine infusion. After
completion of radiofrequency ablation, IAI of the hip will follow as described for the
control group above.
1Research sites
70Patients around the world