Chronic Pain Following Unicompartmental Knee Arthroplasty: A Narrative Review and Illustrative Case Report on Genicular Artery Embolization Using Imipenem/Cilastatin

Background: Chronic pain after unicompartmental knee arthroplasty (UKA) represents a significant clinical issue, often unrelated to mechanical causes and resistant to standard therapies. This work combines a narrative review and a case report to explore the pathophysiological mechanisms underlying persistent post-UKA pain and to propose genicular artery embolization (GAE) with Imipenem/Cilastatin (IPM/CS) as a novel minimally invasive treatment option. Methods: A comprehensive literature review was conducted to analyze current diagnostic and therapeutic approaches to chronic post-UKA pain, with emphasis on vascular and inflammatory mechanisms. Additionally, a patient with chronic lateral knee pain refractory to conservative management underwent selective GAE targeting hypervascularized genicular branches. Results: Following the procedure, the patient experienced substantial and sustained pain reduction, functional improvement, and no complications. The literature supports synovial neovascularization as a potential pain generator and confirms the safety of IPM/CS due to its transient embolic effect and preservation of normal perfusion. Conclusions: The combination of literature review and clinical evidence suggests that GAE may represent a promising therapeutic alternative for chronic post-UKA pain. Further studies are needed to confirm its efficacy, long-term outcomes, and appropriate indications within this challenging clinical setting.