Genicular Artery Embolization in Moderate to Severe Knee Osteoarthritis: Technique, Safety and Clinical Outcome

Abstract

Purpose: To evaluate the safety and clinical outcomes of genicular artery embolization for knee osteoarthritis (OA).

Materials and methods: A total of 43 patients suffering from osteoarthritis of the knee (Kellgren and Lawrence grades 2-4) were included in this prospective study. Peri-interventional data including vascular access, embolized target vessels, fluoroscopy time and radiation dose were collected. After 2-, 3- and 12-month pain scores, functional outcomes and adverse events were assessed through a standardized questionnaire.

Results: All embolizations were performed via a coaxial system consisting of a 4F Cobra catheter and a Microcatheter without the use of an introducer sheath. A mixture of contrast agent (Accupaque, GE, USA) and microspheres (Embosphere, Merit Medical, USA) was injected. At least three genicular branches were embolized per patient with following incidence: inferior lateral genicular artery (77%), superior lateral genicular artery (74%) and descending genicular artery (74%). The mean total volume of permanent embolic agent used was 3.6 ± 1.3 ml. The average fluoroscopy time was 29 ± 11 min, and radiation dose was 40.84 ± 26.21 Gy/cm². During the 1-year follow-up, patients pain while walking showed an average reduction of 2.0 ± 0.5 points on the numeric rating scale (p < 0.0001), without any significant difference between different grades of osteoarthritis. Besides mild transient skin discolorations in four patients, no complications were observed.

Conclusion: Embolization of multiple genicular artery branches in a single session using microspheres in averaged doses higher than 2 ml total is safe and effective in reducing pain and improving functionality in patients with symptomatic OA, regardless of severity grade.

Keywords: Clinical outcome; Genicular artery embolization; Radiation exposure; Safety; Technique; Vascular complications.

Fig. 1

Case example. Embolization in a 78-year-old male suffering from KL-Grade 4 osteoarthritis via an antegrade transfemoral access with a coaxial system consisting of a 4F Cobra catheter and a 1.7 F microcatheter without the use of an introducer sheath. Extensive vascular blush was seen in the descending genicular artery (DGA), inferior medial genicular artery (IMGA) and inferior lateral genicular artery (ILGA). The superior medial genicular artery (SMGA) and the superior lateral genicular artery (SLGA) showed only minimal vascular blush and were embolized in the same session

Fig. 2

English translation of the patient questionnaire

Fig. 3

Technical procedural parameters. Schematic of the genicular arteries adapted by Callese et al. [30]. DGA: Descending genicular artery; SLGA: Superior lateral genicular artery; ILGA: Inferior genicular artery; SMGA: Superior medial genicular artery; IMGA: Inferior medial genicular artery and MGA: Middle genicular artery. (Percentage of patients in which the vessel was embolized; mean ± SD [Minimum–Maximum] volume of permanent embolic agent injected per vessel)

Fig. 4

Changes in pain and function after GAE. QoL: Quality of life and ADL: Activities of daily living; ns: p > 0.05; *p = 0.01–0.05; **p = 0.001–0.01; ***p = 0.0001–0.001 and ****p < 0.0001

Fig. 5

Changes in pain and function after GAE for OA grades II, III and IV. Q1: Pain at rest; Q2: Waking pain; Q3: Pain while climbing stairs; Q4: Morning pain; Q5: Evening pain; Q6: Night pain; Q7: Mobility impairment; Q8: Social isolation; Q9: Quality of life impairment and Q10 Activities of daily living impairments; ns: p > 0.05; *: p = 0.01–0.05; **p = 0.001–0.01; ***p = 0.0001–0.001 and ****p < 0.0001