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Interv Pain Med
Interv Pain Med
Interventional Pain Medicine
2772-5944
Elsevier

S2772-5944(22)00004-8
10.1016/j.inpm.2022.100013
100013
Letters to the Editor
Treatment of refractory greater trochanteric pain syndrome with cooled radiofrequency ablation☆☆☆
Vajdi Tina tina.vajdi@cshs.org
∗
Pouldar Tiffany
Vijjeswarapu Mary A.
Rosner Howard
Department of Anesthesiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
∗ Corresponding author. Cedars-Sinai Medical Center, Department of Anesthesiology, 8700 Beverly Blvd #4209, Los Angeles, CA, 90048, USA. tina.vajdi@cshs.org
☆ Dr. Rosner has the following conflict to declare: he teaches cadaver sessions for Avanos on RF techniques.

☆☆ Drs. Vajdi, Pouldar, and Vijjeswarapu do not have any relevant conflicts to declare.

02 2 2022
3 2022
02 2 2022
1 1 10001315 12 2021
18 1 2022
18 1 2022
© 2022 The Author(s)
2022
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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pmcDear Editor:

We present a novel case of GTPS refractory to conservative and surgical treatments that was successfully treated with cooled radio frequency ablation after diagnostic identification of the sensory nerve supply to the trochanteric bursa. Afterwards, we discovered two similar cases reported in the article titled “Cooled Radiofrequency Ablation of the Trochanteric Branch of the Nervus Femoralis to Treat Greater Trochanteric Pain Syndrome” by Abd-Elsayed A, Cui C, Eckmann MS and published in Pain Medicine.

In adults, greater trochanteric pain syndrome (GTPS) is a leading cause of lateral hip pain. It affects 1.8 to 5.6 per 1000 adults annually and is more commonly found in women [1,2]. Patients report worsening pain with ambulation, standing, and lying on the affected hip. Over time, the pain can intensify and worsen. On physical examination, pain with direct palpation of the greater trochanter as well as a positive single leg stance test can be used to clinically diagnose GTPS. Typically, it is treated with conservative treatments such as weight loss, physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), and/or corticosteroid injections. For recalcitrant GTPS, surgical interventions such as a bursectomy or iliotibial band lengthening are considered.

Our patient is a 79-year-old woman who was referred to our interventional pain clinic for bilateral GTPS. In addition to GTPS, she had a past medical history of rheumatoid arthritis. She reported intermittent, non-radiating, sharp pain in her bilateral lateral upper thighs for 18 months prior to presentation. Her rheumatologist had been treating her with steroid injections every 3–6 months for trochanteric pain. Each injection provided her with approximately one month of pain relief. She had tried physical therapy and NSAIDs, which did not significantly improve her pain. An MRI of her right hip showed mild trochanteric bursitis and degenerative changes of the sacroiliac joint.

Initially, we tried bilateral greater trochanteric bursa injections under fluoroscopic guidance using 25-gauge, 3.5inch Quincke-type spinal needles, which were inserted into the bilateral greater trochanteric bursa from a posterior approach. After negative aspiration, 0.25mL of iohexol 240mg/mL was injected. Appropriate spread of the contrast was identified before 1mL of 0.75% bupivacaine and 0.25mL of betamethasone were injected bilaterally (Fig. 1). Although, the injection initially helped decrease her pain, it did not provide lasting pain relief.Fig. 1 Fluoroscopically guided bilateral trochanteric bursa injection with contrast. A. Left-sided injection. B. Right-sided injection.

Fig. 1

Unfortunately, our patient's pain did not improve with these conservative treatments, and her pain was worse on the right side. Therefore, she underwent a right sided hip arthroscopy, trochanteric bursectomy, and iliotibial band lengthening. She continued to see her physical therapist, but one month post-operatively, her trochanteric pain returned despite surgical intervention. Given the refractory nature of her GTPS and the lack of lasting pain relief from traditional interventions, we sought a novel way to treat her pain.

A study from Genth et al. determined that the sensory innervation to the trochanteric bursa arises from a network of mostly unmyelinated fibers that originate from the femoral nerve [3]. They enter the periosteum of the greater trochanter just caudal to the inferior gemellus muscle. Therefore, we hypothesized that we could identify the sensory nerve fibers, sometimes referred to as nervus femoralis, that supply the greater trochanter and ablate them in order to alleviate our patient's refractory GTPS. Four months later, we performed a peripheral nerve block of the bilateral sensory nerves that innervate the trochanteric bursa. Under local anesthesia and fluoroscopic guidance, a 25-gauge, 3.5inch Quincke-type spinal needle was introduced approximately two-thirds of the distance down the trochanter at two different locations 1cm apart to maximize the spread of the medication to the network of sensory nerves as shown in Fig. 2. Fluoroscopy views were obtained in a straight anterior-posterior direction. The obturator foremen was equalized bilaterally then the C-arm was pulled laterally without changing any angles to visualize the femoral head and trochanter centered. Then, 0.5mL of 0.5% ropivacaine and 0.2mL of triamcinolone was injected without significant resistance, divided between two locations (Fig. 3). The procedure was then repeated on the contralateral side. Her pain score decreased from 8/10 pre-procedure to 0/10 post procedure; therefore, we were able to verify that we successfully identified the sensory innervation of the trochanteric bursa.Fig. 2 Diagram of the sensory innervation to the greater trochanter. The femoral nerve branch (green) enters the periosteum of the greater trochanter just caudal to the inferior gemellus muscle (yellow). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

Fig. 3 Fluoroscopically guided peripheral nerve blocks of the bilateral sensory nerves that innervate the trochanteric bursa. A. Left-sided injection. B. Right-sided injection.

Fig. 3

Although our interventional treatment to identify the meshwork of sensory fibers innervating the trochanteric bursa is like that in the study by Abd-Elsayed et al., there are a few differences [4]. We opted to use different amounts of local anesthetic than used in their case series, which is due to the preferences of the different physicians. Additionally, the preferred a steroid-sparing approach, but we did not since our patient had no contraindications for receiving steroids. Further studies are necessary to determine the optimal medications and doses needed to predict successful responses to cooled RFAs of the innervation to the trochanteric bursa.

After successfully reducing her pain, we hypothesized that cooled RFA to provide lasting pain relief as we would for sacroiliac or facet joints. The posterior aspect of the greater trochanter lacks major vasculature or motor nerves. As described by Abd-Elsayed et al. damage to the gluteus medius tendon can be avoided, so we anticipated that RFAs can be safely performed without significant impairment of hip function. One month following her procedure, she returned to our pain center to have bilateral radiofrequency ablations (RFAs) from the posterior approach performed under moderate sedation. 17-gauge, 3.5-inch Halyard Coolief needles were introduced approximately two-thirds of the distance down the left greater trochanter at two different locations 1cm apart. 0.75mL of 2% lidocaine was injected into each of the locations through the needles after negative aspiration. Then, RFA was performed through an internally cooled radiofrequency probe (Halyard Coolief needles) at 60° to heat the adjacent tissue to 85 ​°C for 150 seconds. The advantage of a cooled RF probes over traditional RF probes is that cooled RF probes create a larger, spherical lesion shape when ablating, thus providing more extensive denervation [5]. Additionally, the circulating water in the cooled RF probes allows for lower temperatures and less burning of adjacent tissues, which is why the authors chose cooled RFA over traditional RF for this patient [6]. Following the RFAs, 0.75mL of 0.5% ropivacaine and 10mg of triamcinolone was injected without significant resistance at each location on the left side in order to decrease post-procedural pain (Fig. 4).Fig. 4 Fluoroscopically guided cooled radiofrequency ablations. A. Left-sided RFA. B. Right-sided RFA.

Fig. 4

When comparing our RFA probe placement to those of Alb-Elsayed et al., we noticed that they placed their probes slightly higher than we opted to. Since the sensory innervation to the trochanteric busa is a meshwork rather than a very specific innervation, we account our differences due to targeting different areas within the same meshwork of sensory nerves. Larger studies are needed to identify optimal placement of the RFA probes within this sensory meshwork to the trochanteric bursa.

She continues to have significant pain relief after ablating the sensory nerves that innervate the trochanteric bursa, and she consented reporting of this case. Currently, she continues to follow up in our pain clinic and has had 4 months of pain relief, which is the longest period of time she has experienced pain relief.

Our patient and the patients described by Abd-Elsayed et al., demonstrate that cooled radiofrequency ablation is a safe and efficacious modality that we can add to our armamentarium when treating refractory GTPS.

Funding

No funding was obtained for this manuscript.
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References

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3 Genth B. Von During M. Von Engelhardt L.V. Ludwig J. Teske W. Von Schulze-Pellengahr C. Analysis of the sensory innervations of the greater trochanter for improving the treatment of greater trochanteric pain syndrome Clin Anat 25 2012 1080 1086 22374737
4 Abd-Elsayed A. Cui C. Eckmann M.S. Cooled radiofrequency ablation of the trochanteric branch of the nervus femoralis to treat greater trochanteric pain syndrome Pain Med 2021 Jun 27 pnab207 10.1093/pm/pnab207 Epub ahead of print. PMID: 34175957
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