2 The condition, current treatments and procedure
2.1 Osteoarthritis is characterised by localised loss of cartilage, remodelling of adjacent bone, and associated inflammation. Knees are one of the most affected joints, with pain being a significant symptom.
2.2 Angiogenesis may contribute to inflammation, structural damage and pain. This is because the increased vascular network carries inflammatory cells to the synovium and other joint tissues and promotes additional hyperplasia and inflammation in other vessels, leading to bone and cartilage destruction. Angiogenesis also enables the growth of new unmyelinated sensory nerves, which contributes to pain.
2.3 For pain secondary to knee osteoarthritis, various treatments are available including non-pharmacological (such as physiotherapy), pharmacological (such as analgesics and intra-articular steroids) and surgical approaches (such as knee arthroplasty).
2.4 Treatment most commonly involves a combination of pharmacological and non-pharmacological interventions. When non-pharmacological and pharmacological interventions do not work or symptoms are severe, surgery may be needed.
2.6 Before the procedure, contrast-enhanced MRI of the knee is done to allow non-invasive assessment of synovial hypervascularity. The procedure is usually done using local anaesthesia with or without sedation. A catheter is passed through an introducer sheath in the femoral artery and then navigated into the genicular arteries supplying the knee to perform lower extremity angiography on the targeted side. Once the abnormal new vessels arising from these arteries are identified, a microcatheter is navigated into them and, under fluoroscopic guidance, tiny embolisation particles are then delivered until the blood flow is stopped.
2.7 After the introducer sheath and catheter are removed, haemostasis is achieved with manual compression or a vascular closure device. The patient often goes home the same day. This procedure takes approximately 1 to 2 hours to complete.