Techniques for Percutaneous Image-Guided Radiofrequency Ablation for Chronic Hip Pain

Monday, March 6, 2023

5:35 PM – 5:40 PM

Location: Phoenix Convention Center, North Ballroom 120ABC, Poster Hall

Abstract Presenter(s)

Stephanie Y. Johng, MS

Medical Student
Georgetown University School of Medicine

Disclosure(s): No financial relationships to disclose

Author/Co-author(s)

Neil K. Jain, DO (he/him/his)

Integrated Interventional Radiology Resident
Medstar Georgetown University Hospital
Kaitlin A. Carrato, MD

Resident Physician
MedStar Georgetown University Hospital
John B. Smirniotopoulos, MD

Assistant Professor of Radiology
MedStar Georgetown University Hospital

Disclosure(s):

Stephanie Y. Johng, MS: No financial relationships to disclose

Kaitlin A. Carrato, MD: No financial relationships to disclose

John B. Smirniotopoulos, MD: ABBOTT, ANGIODYNAMICS, ANGIOSAFE, BD BARD, BOSTON SCIENTIFIC, CSI – FRONTIER, INTACT VASCULAR, ABBOTT, MEDTRONIC, MICRO MEDICAL SOLUTIONS, PLURISTEM, LTD SURMODICS, VERYAN, VESPER MEDICAL: Consultant (Ongoing)

Learning Objectives:

To review the anatomical targets, diagnostic imaging, patient selection, procedural approach, potential complications, and reported outcomes in percutaneous radiofrequency ablation (RFA) of articular branches of the femoral (FN) and obturator nerve (ON) to treat chronic hip pain.

Background:

Hip pain, presenting as groin or posterolateral pain, is prevalent in 7-10% of patients over the age of 45, most commonly due to osteoarthritis, which can impact ambulation and quality of life. RFA is commonly used to treat chronic knee and back pain. With the emergence of new techniques and a better understanding of the intricate anatomy of the hip, adaptation of RFA for refractory hip pain can provide relief for patients without the extended recovery period.

Clinical Findings/Procedure Details:

Patients considering RFA first undergo diagnostic nerve blocks. Under fluoroscopy, a 25-gauge or 22-gauge spinal needle is advanced to the cortex at the anatomic landmarks for the articular branches of the FN (12 o’clock superior acetabular position) and the ON (just inferior to the “teardrop” silhouette at the junction of the pubic and ischial bones). 1-2 mL of 0.5% bupivacaine is then injected at each site. A patient is deemed a good candidate for RFA if they report at least a 50% reduction in their pain.

For the RFA, a 17-gauge Coolief RF introducer cannula is advanced under fluoroscopy to the anatomic locations of the articular branches of the FN and ON. 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 are observed. Ablation at each nerve site is performed for 2 minutes to reach a target temperature of 80 degrees. Evidence from cadaveric studies have suggested that repositioning the ON probe 1 cm inferior to the first target for a second ablation has superior results. A small volume of 0.75% bupivacaine and triamcinolone is then administered at each ablation site.

This procedure takes about 15 minutes with total fluoroscopy time under 0.8 minutes. The patients can go home after a 30 minute observation. Available studies demonstrate 100% technical success with immediate post-operative relief which has been replicated in our clinical practice. Patients are scheduled to follow-up at 1- and 6-months post procedure, and the ablation can be repeated if needed.

Conclusion and/or Teaching Points:

Percutaneous RFA of the hip joint is a minimally invasive, outpatient intervention that can bring immediate long-term functional improvement to patients with recalcitrant hip pain who are poor surgical candidates.