Cadaveric and Angiographic Anatomical Considerations in the Genicular Arterial System: Implications for Genicular Artery Embolisation in Patients with Knee Osteoarthritis

PURPOSE Genicular artery embolisation (GAE) is a novel treatment for patients with knee osteoarthritis (OA). Cadaveric dissection was undertaken to provide a complete description of the relevant arterial anatomy in order to perform safe and effective GAE. MATERIALS Twenty human lower limb specimens were dissected. The morphology of the genicular arteries and presence of anastomotic connections was recorded and compared with angiographic images from patients having undergone GAE. Vessels were measured to investigate the risk of non-target embolisation (NTE), taking a diameter of 300 microns as the threshold for significance. RESULTS The descending genicular artery (DGA) is the dominant vessel in medial OA, with 95% of cases revealing vessel division into muscular, saphenous and osteoarticular branches from a single pedicle. The superior medial genicular artery (SMGA) had a shared origin with the middle genicular artery (MGA) in 25% of cases. NTE to the MGA may damage the cruciate ligaments. In 85% of cases, there was an anastomosis between the DGA and SMGA, often encountered at angiography. The mean diameter of the anastomoses was 850 micron, presenting a risk for NTE. An anastomosis between the Inferior Medial Genicular Artery (IMGA) and medial sural artery was found in 5% of cases; the medial sural artery supplies blood to the tibial nerve and should be avoided. The IMGA and inferior lateral genicular artery provided supply to the patellofemoral joint in 69% and 88% of cases, respectively. CONCLUSION An in-depth knowledge of genicular artery anatomy is required for interventional radiologists to perform safe and effective GAE in patients with knee osteoarthritis.