BACKGROUND: Chronic knee pain associated with advanced osteoarthritis (OA) presents a significant challenge in pain management, especially when conservative treatments fail to provide relief.

CASE REPORT: Four patients with chronic knee pain due to Kellgren-Lawrence OA grade 4 (severe) classification were selected for permanent implantation of the Freedom® Peripheral Nerve Stimulation (PNS) System at the infrapatellar saphenous (IPS) nerve. Pain reduction and responder rates were assessed before and after treatment. Long-term follow-up data were collected to evaluate pain relief, function, quality of life, and medication usage. All 4 patients experienced > 50% pain relief following the trial period, significantly reducing mean pain scores from baseline. Long-term follow-up revealed sustained pain reduction and functional improvement, with no reported adverse events associated with the procedure.

CONCLUSIONS: PNS targeting the IPS nerve with the Freedom PNS System demonstrates efficacy and safety in managing chronic knee pain associated with Kellgren-Lawrence OA grade 4 classification.

KEYWORDS: Kellgren-Lawrence grade 4, Peripheral nerve stimulation, chronic knee pain, infrapatellar saphenous nerve