Techniques for Percutaneous Image-Guided Cooled Radiofrequency Ablation for the Management of Refractory Greater Trochanteric Pain Syndrome

To describe the pathophysiology of greater trochanteric pain syndrome (GTPS) as well as indications and procedural techniques for image-guided cooled radiofrequency ablation (CRFA) of the trochanteric nerves.

Background:

GTPS is one of the most common causes of lateral hip pain in adults and is caused by repetitive hip abduction and stabilization motions resulting in gluteus medius and minimus tendinopathy. After failed conservative therapy, glucocorticoid injections may offer short-term pain relief, however, repeated injections pose a risk of steroid-induced tendon rupture and many patients will continue to experience chronic pain despite intervention. CRFA of the trochanteric branches of the femoral nerve is a minimally invasive approach to treat refractory GTPS in select patients {1}.

Clinical Findings/Procedure Details:

Patients with chronic GTPS considering CRFA first undergo diagnostic nerve blocks. The patient is placed in a prone position. Under fluoroscopy, the anatomical landmarks for the trochanteric branches of the femoral nerves at the femoral head and greater trochanter are identified. The posterior aspect of the greater trochanter is targeted to avoid the insertions of the gluteus medius and quadratus femoris. Two 25-gauge or 22-gauge spinal needles are advanced under fluoroscopic guidance to the periosteum.  A small volume of 0.5% bupivacaine is injected at each site. A patient is deemed a good candidate for CRFA if they report at least a 50% reduction in their pain. 

For the ablation, two 17-gauge CRFA introducer cannulas are advanced under fluroscopy to the anatomic locations of the trochanteric nerves. The ablation probes are then advanced through the cannulas and motor function testing using 2Hz/2V stimulation is performed to ensure no gross muscle fasciculations.  Ablation at each nerve site is performed for 2 minutes to reach a target temperature of 80 degrees. A small volume of 0.75% bupivacaine and triamcinolone are administered at each ablation site to control pain and inflammation.

This outpatient procedure takes approximately 15 minutes with a total fluoroscopy time under 0.8 minutes and minimal blood loss. After observation for 30 minutes in the post-operative area, patients can go home the same day. Patients are scheduled to follow-up after 1-month and 6-month post procedure, and the ablation can be repeated if needed.

Conclusion and/or Teaching Points:

Percutaneous CRFA of the greater trochanter is a minimally invasive, outpatient intervention that can bring immediate long-term functional improvement to patients with greater trochanteric pain syndrome who are poor surgical candidates.