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5 Articles in this Series
Introduction
Audience Q&A: My Patients Don't See a Need for a Psychologist
Debate: Radiofrequency Ablation of the Hip (and Shoulder) Joint is Effective
Debate: SCS Is Better Than PNS for Back Pain
Inside the Poster: Methylnaltrexone for Opioid-Induced Constipation
The Deprescribing of Opioids: Toward Whole-Person Pain Care

Debate: Radiofrequency Ablation of the Hip (and Shoulder) Joint is Effective

with Amitabh Gulati, MD, and Zirong Zhao, MD, PhD

 

As part of its annual debate session, AAPM 2020 presenters weighed the pros and cons of radiofrequency ablation for joint pain, focusing on the hip and shoulder. Below are highlights from the debaters.

 

Pro: Amitabh Gulati, MD, director of chronic pain, associate attending, and program director of the Weill Cornell Pain Medicine Fellowship, all at Memorial Sloan Kettering Cancer Center in New York. Dr. Gulati disclosed that he is a consultant to Medtronic, Flowonix, AIS, SPR Therapeutics and Nalu Medical.

Let’s do RFA, but to which joints, Dr. Gulati asked the audience. While injections have been conducted in the knee, facet, and sacroiliac joints for pain and, more commonly, for metastatic pain, he questioned whether the medical community has a reliable and reproduceable technique with a low side effect profile for these procedures.

Dr. Gulati pointed out that the shoulder is the least studied joint to date. While innervation of the shoulder joint is pretty consistent, he shared, radiofrequency ablation (RFA) may not  preserve function. “We are not easily able to see the articular branches to de-innervate the joint even with image guidance, especially end branches,” he noted. “As a result, there is only a reasonable (50%) chance of success.”

With the more complex hip joint, nerves exist in different locations and come from different neural pathways. Some studies have shown a 50% reduction in pain scores for 3 to 6 months but related opioid reduction is questionable and few studies have verified improved physical function, he added. Dr. Gulati clarified that, in general, clinicians can safely target the femoral components of the hip under ultrasound or fluoroscopy, but less commonly can they target the obturator nerve.

So why consider RFA  of joints at all? “There is a patient population that does not benefit from the end part of pain treatment, that is, surgery. They may have COPD or lymphoma or be too young or be on steroids—we wouldn’t do joint replacements in those populations,” offered Dr. Gulati, adding that, “There is a shorter recovery period for the RFA compared to joint replacement.” To fully justify RFA, however, as compared to cryoablation and neuromodulation options, there are anatomical challenges of the joints that need more review, as well as more research into sensory and motor testing parameters, he noted. “Then we will better know what to ablate and what not to not ablate. Overall, the decision should be based on potential quality of life outcome and patient selection of treatment.”

There is far more literature on the innervation of the hip joint. (Image: iStock)

Con: Zirong Zhao, MD, PhD, chief of interventional pain at the Veterans Affairs Medical Center in Washington DC

Although Dr. Zhao presented the “con” side of the debate, she noted upfront that she supports effective RFA of the joints but wanted to offer additional perspective.  She shared 15 studies published in the literature between 1993 and 2018 on the use of RFA for chronic hip pain, noting that out of a sum of 126 patients across these studies, 79 had osteoarthritis (OA) as the predominate etiology; others had a variety other diagnoses. The relevant studies showed pain reduction and improved function but there were also complications noted (such as hematoma, cutaneous numbness, and decreased sensation). “Complications often don’t come to light until later when a large number of cases are accumulated, because the incidence of complications is low and because studies don’t look at complications always,” she said. The studies reviewed in fact were not designed to look at complications.

With regard to shoulder pain, Dr. Zhao shared 18 studies conducted between 1966 and 2018 of RFA for the suprascapular nerve showing that it may be safe and beneficial. Additional studies from 1993 to 2019 targeting the terminal sensory articular branches were reviewed as well. One of the earlier studies showed that intra-articular injections seemed to provide faster improvement compared to pulsed radiofrequency for the suprascapular nerve. Additional cases targeting the terminal sensory articular branches showed encouraging results as a tool to control shoulder pain.  One publication, a case series by Eckmann et al, reported a responder rate of 47% when the definition of success was defined as 50% pain relief for 3 months.

“When we look at treatment effectiveness, the literature shows that studies of RFA for hip and shoulder are largely based on studies of lower quality such as case reviews and case reports vs higher quality studies (RCTs), so we don’t have a great body of evidence overall,” she said, agreeing with Dr. Gulati’s point on existing literature to date.

In terms of identifying potential candidates for RFA of the hip, Dr. Zhao pointed to joint pain etiologies in available studies such as OA and RA, as well as avascular necrosis, persistent pain after hip arthroplasty, cancer-related pain, and post-injury pain. For the shoulder, she noted OA (glenohumeral and acromioclavicular joints), adhesive capsulitis, rotator cuff tendinopathy, RA, subluxation of the shoulder joint in hemiplegia, cancer-related pain, and post-injury pain.

She further agreed with Dr. Gulati that anatomy is a key challenge due to its variability from person to person. She also agreed that when conservative pain management does not work and when surgery is not desired or not an option, RFA treatment may be considered. But, she cautioned, “Keep in mind that studies are low quality and there is no long-term data, plus, there are gaps in the details.” 

 

 

Next summary: Debate: SCS Is Better Than PNS for Back Pain
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