Genicular artery embolization for refractory pain after knee arthroplasty: clinical outcomes from a retrospective pilot study

Abstract

Abstract Background Refractory pain after knee arthroplasty without prosthetic loosening, infection, or mechanical failure remains a therapeutic challenge for which few non-surgical options are available. Genicular artery embolization (GAE) has shown promise in knee osteoarthritis, but evidence in patients treated after arthroplasty remains limited. The aim of this study was to evaluate the technical feasibility, safety, and short- to mid-term clinical outcomes of GAE using imipenem/cilastatin (IPM/CLS) in this population. Results Fifteen consecutive patients (9 men, 6 women; median age, 67 years) underwent GAE between January 2022 and December 2025 for refractory pain after total knee, unicompartmental, or isolated retropatellar arthroplasty. Hypervascular periarticular branches were embolized with an IPM/CLS suspension through common femoral arterial access. Outcomes were assessed using the Numeric Rating Scale (NRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Total Analgesic Consumption Score (TACS) at baseline and 1, 3, 6, and 12 months. Technical success was 100%. Median NRS fell from 7.0 (interquartile range, 6.0–8.0) at baseline to 1.0 at 1 month ( p < 0.001), 3.0 at 3 and 6 months, and 5.0 at 12 months ( p = 0.018). Median WOMAC decreased from 32.0 to 20.0 ( p = 0.032) and KOOS from 20.0 to 14.0 ( p = 0.041) at 12 months. TACS improved significantly through 6 months ( p ≤ 0.026); 4 of 7 patients on baseline opioids had discontinued by 12 months. At 12 months, 5 of 9 evaluable patients (56%) maintained a ≥ 2-point NRS reduction and 4 of 9 (44%) achieved a ≥ 30% reduction. Repeat embolization was performed in 3 patients (20%). No major complications occurred; minor transient adverse events occurred in 2 patients (13%): mild periarticular discomfort and self-limited skin erythema. Conclusions In this small retrospective pilot cohort, GAE using IPM/CLS appeared technically feasible and safe and was associated with early pain reduction. Sustained clinically meaningful benefit at 12 months was limited to a subset of patients, indicating variable durability. These findings should be interpreted with caution and require confirmation in larger prospective studies.