2022 FSA Podium and Poster Abstracts

S006: SUSTAINED RELIEF OF FOCAL KNEE PAIN AFTER BILATERAL PATELLECTOMY WITH L3 DRG STIMULATION
Joshua Winegar, MD; Juan Mora, MD; University of Florida

Introduction: Chronic knee pain is a common condition with multiple underlying etiologies. When conservative therapies and surgical treatments fail, advanced pain management strategies can be considered. While joint pain is often considered mechanical and nociceptive in nature, chronicity and surgical interventions in the area may lead to the development of a neuropathic component. The dorsal root ganglion (DRG) consists of sensory nerve cells and is involved in the neuropathic pain pathway. Stimulation of the DRG is a known option for treating pain in focused regions and is approved for the treatment of chronic intractable pain of the lower limbs. In such instances of chronic refractory focal knee pain, stimulation of the DRG may be an appropriate treatment option.

Case: A 59-year-old female with a past medical history significant for rheumatoid arthritis, multiple joint osteoarthritis, and Sjogren’s disease presented with 40 years of bilateral knee pain following numerous surgeries, including a Maquet procedure, lateral releases, neuroma resections, and bilateral patellectomies. The patient did not respond to conservative treatment options, including medication management with NSAIDs, duloxetine and opioids and interventions such as lumbar sympathetic plexus block and corticosteroid injections. She was also not deemed to be a candidate for knee arthroplasty by the orthopedic physician.

A trial of DRG stimulation therapy was performed, and leads were positioned at the L3 DRG bilaterally, resulting in coverage of the painful areas of both knees. At the end of the seven-day trial, the patient obtained 100% and 80% pain relief on the left and right knee, respectively. Thereafter, this patient underwent a permanent implant. The patient tolerated both the trial and permanent implant procedures well and has had sustained durable benefit from the DRG stimulation therapy.

Results: This patient has done exceedingly well following neuromodulation therapy at the L3 DRG bilaterally with a decrease in her numeric rating scale (NRS) pain score from 8-9/10 to 0/10 in the left knee and 2/10 in the right knee with activity. At 9-month follow up visit pain relief is sustained at 80-100% and her ability to participate with PT and do her daily activities has improved, which is reflected on her ODI and PROMIS-29 scores.

Discussion: This case highlights a successful outcome with stimulation of the L3 DRG in a patient with refractory knee pain following multiple surgeries. Although joint pain is typically mechanical and nociceptive in nature, chronic knee pain complicated by multiple surgeries may develop a mixed nociceptive and neuropathic pain component. In these instances, stimulation of the DRG may be considered a suitable long term treatment option.