Percutaneous 60-day PNS for Treating Chronic Knee Pain: Outcomes from a Multicenter, Retrospective Chart Review

Introduction: Chronic knee pain impacts approximately one in four adults and impairs mobility and function[1]. Conventional pain treatment options often lack sustained efficacy and can produce unwanted side effects[2]. Percutaneous 60-Day Peripheral Nerve Stimulation (PNS) has demonstrated efficacy for reducing chronic knee pain, including in a multicenter randomized placebo-controlled trial in participants with postoperative knee pain[3]. This multicenter retrospective chart review evaluated real-world outcomes using Percutaneous 60-Day PNS to treat chronic knee pain.

Methods: An IRB-approved retrospective chart review was conducted at three sites and included patients who had completed treatment with Percutaneous 60-Day PNS for their chronic knee pain. Percutaneous 60-day PNS is an FDA-cleared treatment for use up to 60 days, after which leads are removed. Demographic characteristics, medical history, safety, and patient-reported outcomes at the end of treatment (EOT) were extracted from each site’s electronic medical records (EMR) and supplemented with information from the manufacturer’s database. Patients were treated with either one or two leads implanted to stimulate nerves innervating the knee (e.g., saphenous, femoral, sciatic). The proportion of patients who reported clinically substantial (≥50%) pain relief was evaluated at EOT. The proportion of patients with at least “minimally improved” quality of life (Patient Global Impression of Change [PGIC] ≥1; -3 to 3 scale) was also assessed.

Results: Across three study sites, 155 patients received Percutaneous 60-Day PNS treatment for knee pain. Outcomes were available for 148 patients at EOT, with clinically substantial (≥50%) pain relief reported in 76% (n=113/148). Among patients reporting PGIC, 71% (n=65/92) reported improved quality of life. The proportion of patients with clinically substantial pain relief was consistently high across pain etiologies, including patients with multiple etiologies: osteoarthritis (n=60/74; 81%), post-traumatic pain (n=20/28; 71%), nerve injury (n=48/59; 81%), and post-operative pain (n=34/45; 76%). Among patients treated for postoperative pain after a prior total knee arthroplasty, 75% (n=27/36) reported clinically substantial pain relief. No serious adverse events were reported.

Conclusion: Percutaneous 60-Day PNS offers a non-surgical, minimally-invasive treatment option for chronic knee pain. These real-world findings build on evidence from a prior randomized controlled trial demonstrating the safety and effectiveness of Percutaneous 60-day PNS in relieving persistent postoperative knee pain. The present analysis further supports its safety and effectiveness across different knee pain etiologies, consistent with other recent data showing 4-5 years of pain relief across multiple pain etiologies[4, 5].