Peripheral Nerve Stimulation of the Saphenous Nerve at the Adductor Canal for Chronic Post-Surgical Knee Pain Following Total Knee Arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is effective for osteoarthritis (OA), yet many patients develop chronic postoperative pain. Peripheral nerve stimulation (PNS) has emerged as a minimally invasive alternative for refractory pain. CASE REPORT: A 79-year-old man with right total knee arthroplasty (TKA) presented with right knee pain unresponsive to genicular nerve radiofrequency ablation. The pain, rated 8/10, was localized to the superomedial knee and worsened with ambulation. Before knee replacement, his pain was confined to the intra-articular space. A peripheral nerve stimulation (PNS) trial targeting the saphenous nerve at the adductor canal was performed under ultrasound guidance. The patient reported 100% pain relief at 1-month follow-up. A Permanent Nalu implant was subsequently placed and that 100% pain relief continued for more than 2 months. CONCLUSIONS: This case demonstrates the use of ultrasound-guided peripheral nerve stimulation targeting the saphenous nerve for chronic postsurgical knee pain following total knee arthroplasty. The intervention provided complete pain relief, underscoring peripheral nerve stimulation as a promising, minimally invasive option for chronic postoperative pain unresponsive to conventional treatments.