Neovascularization Embolisation for Knee Osteoarthritis.(NEO)

Rationale:

Transcatheter arterial embolization has recently been proposed as an efficacious therapy for therapy-resistant osteoarthritis of the knee, providing substantial pain reduction at short-term as well as long-term follow-up up till 4 years.

A potential working mechanism of treatment effect is that the normalization of the amount of blood vessels and blood flow achieved by embolization reduces inflammation, resulting in pain reduction

Objective:

The main objective is to assess whether transcatheter arterial embolization of neovessels in patients with symptomatic knee OA results in significant pain reduction after 4 months compared to sham treatment.

The investigators hypothesize that novel transcatheter arterial embolization of neovessels is a feasible, effective, and safe treatment for patients with symptomatic radiographic knee OA, resulting in significant improvement of pain symptoms in a period of 4 months follow-up compared to sham embolization.

Secondary objectives are

• to assess whether reduction of neovessels is related to pain relief,
• to explore whether decrease of inflammation is a mediating factor between neovessel reduction and pain relief,
• to assess whether transcatheter arterial embolization reduction of neovessels decreases peripheral and central pain sensitization and
• to assess whether transcatheter arterial embolization improve the outcome at 1, 4, 8 and 12 months compared to placebo of the: ICOAP, painDETECT, EQ-5D-5L questionnaires and NRS for pain.

Inclusion criteria

• Age.≥18 years
• Knee pain for a duration of ≥ 6 months
• Knee pain (numeric rating scale ≥4 - ≤8) on at least half of the days in the preceding month at time of inclusion.
• There is insufficient response of conservative treatment for at least 6 months
• Radiographic knee osteoarthritis (radiographic Kellgren and Lawrence grade 1-3)

Exlusion criteria:

• Contra-indications for MRI (e.g. metallic foreign bodies, etc.)
• Contra-indications for angiography
• Renal insufficiency, checked with blood sample test (GFR < 30 ml/min/1, 73 m2);
• Known allergy to contrast agents;
• Patient has known allergies to barium sulfate, 3-aminopropyltrialkoxysilane, polyphosphazene
• Women who are pregnant or lactating
• Intermittent claudication of affected limb
• Intra articular injections in the ipsilateral knee less than 6 months ago
• On the waiting list for joint replacement surgery
• Amitriptyline usage.
• Patient has known allergies to barium sulfate, 3-aminopropyltrialkoxysilane, polyphosphazene.
• Insufficient command of the Dutch or English language.
• Legally incompetent adults.