An AAPM 2022 Meeting Highlight with Jonathan Hagedorn, MD, and Michael Leong, MD
Hip, shoulder, and knee pain plague many people, even after surgeries meant to improve quality of life and functioning. Jonathan M. Hagedorn, MD, of iSpine Pain Physicians in Maple Grove, MN, talked about the growing use of peripheral nerve stimulation (PNS) to resolve some of these issues at the American Academy of Pain Medicine (AAPM) 2022 annual meeting. He described appropriate PNS targets to treat knee, hip, and shoulder pain pathologies, including how to best identify candidates.
Peripheral Nerve Stimulation: Permanent or Short-Term Systems
“Peripheral nerve stimulation has been utilized for years, but renewed interest in this treatment modality has allowed the development of devices specifically designed for peripheral nerve placement,” he told PPM after the session. The result, he said, is that people will have better outcomes with fewer complications, and physicians can place the devices with more confidence.
During the session, Dr. Hagedorn addressed the available types of PNS by comparing permanent versus 60-day systems. For conventional PNS, a trial is typically conducted in a patient for about 7 days before considering whether a permanent system implant is ideal.The 60-day PNS systems, or short-term systems, are newer and meant to provide a durable outcome after 60 days.
At the Mayo Clinic in Rochester, MN, where Dr. Hagedorn was recently director of neuromodulation, his colleagues generally start with a nerve block. If the individual experiences relief, in most cases, a 60-day device tends to lead to long-term pain relief. “I’ve kind of carried that forward into my own practice,” said Dr. Hagedorn. “If I can get good long-term pain relief and I don’t have to have a [long-term] implanted device in there, I still think that’s the way to go.”
Specific Nerve Targets for Peripheral Nerve Stimulation
Dr. Hagedorn then shared specific instructions for various PNS targets based on his clinical experience. A few highlights are noted below.
PNS Targets for Knee Pain
Femoral nerve: The electrode target location is superior to the femoral nerve, between the fascia lata and fascia iliaca. The needle is inserted 1 to 2 cm distal to the inguinal crease. It can be a tricky procedure, he said. Image guidance is by ultrasound. Tips: Lateral to medial, superficial to the nerve. Appropriate visualization of the needle tip is crucial. Patient is supine. “You do have to overshoot that nerve a little bit,” he said.
If you are looking at post-amputation pain, this is probably the procedure of choice, he said.
Sciatic nerve: Placement can be transgluteal, subgluteal, or popliteal.
Saphenous nerve: The electrode target location is deep to the sartorius muscle on the medial side. Image guidance is via ultrasound. Tips: Insertion site should allow at least 4 cm of lead under the skin. Be aware of the needle tip relative to the femoral artery.
Evidence: To date, noted Dr. Hagedorn, research on the use of PNS for knee pain has centered on post-total knee arthroplasty (TKA) and post-amputation of the knee. For instance, a 60-day PNS delivered significant pain relief after TKA (average 75%) in one trial. Half of the candidates studied achieved complete pain relief.¹ Dr. Hagedorn suggests that pain specialists partner with orthopedic colleagues – perhaps with pre-operative lead placement. If the surgeons heard about the possibility of bringing down the pain by as much as the studies suggest, he said, “they would be all ears.”
For post-amputation pain, a double-blind, placebo-controlled RCT testing 60-day percutaneous PNS provided significant carry-over effects for pain relief, potentially negating the need for a permanently implanted system.²
PNS Targets for Hip Pain
Peripheral nerve stimulation targets for managing hip pain include lateral femoral cutaneous nerve, superior gluteal, and subcutaneous field stimulation. Dr. Hagedorn focused only on the first, as he does not perform the other techniques.
Evidence: There is much less evidence for hip PNS approaches, Dr. Hagedorn noted. Current post total-hip replacement data is basically one case study, he said, and meralgia paresthetica is about the same. Post-amputation and hemiplegia are probably the areas with the most and best clinical evidence, he added. “I would feel the most comfortable … offering PNS to post-amputation pain,” he said.
Why is hip evidence so sparse, especially considering that total hip (and knee) replacements have been growing steadily and will continue? “'The total hip people always did super well,” said Dr. Hagedorn, recalling his previous work as an orthopedist. “With the knee folks, it’s always a much slower recovery.” Many need short-term rehab facilities and their post-operative recovery just often is not as good, he noted.
PNS Targets for Shoulder Pain
Peripheral nerve stimulation targets for managing shoulder pain include the suprascapular nerve and axillary nerve (quadrangular space, trans-deltoid).
Evidence: An initial study conducted in 2005 compared percutaneous PNS versus conventional care for hemiplegic shoulder pain, finding 78% got relief 12 months after treatment.³ Not many RCTs have followed. This was the first and one of the few, shared Dr. Hagedorn. Then, a follow-up study in 2014 replicated the findings, using a 3-week design.
Practical Takeaways & Perspectives
Among Dr. Hagedorn’s conclusions:
PNS is a growing neurostimulation technique for knee, hip, and shoulder pain
Evidence on PNS is still limited compared to other neurostimulation methods
Evidence is good for the use of PNS in post-amputation pain and hemiplegic shoulder syndrome. For post-TKA pain, small studies suggest it is useful.
Michael Leong, MD, clinical professor of anesthesiology, perioperative. and pain medicine at Stanford University, attended the session. Dr. Hagedorn’s AAPM 2022 discussion, he said, “made some current advanced procedures for treating joints – shoulders, hip, knees – seem simple and applicable for our patients with joint pain.”
Disclosures: Dr. Hagedorn is a consultant, advisory board member and has funded research from Abbott; he is a consultant and advisory board member for Boston Scientific and Nevro, and has received honoraria and funded research from Medtronic; he is a consultant and has funded research from Saluda.