Arterial
Indications
Knee osteoarthritis with persistent moderate to severe knee pain (VAS >3) for a minimum of 6 months despite conservative treatment. This diagnosis should be confirmed via radiograph within last 3 months with Kellgren-Lawrence (KL) classification. The effectiveness for severe OA (KL grade 4) is controversial
Recurrent hemarthrosis
Also promising data for other targets, e.g., frozen shoulder/adhesive capsulitis, hip osteoarthritis, greater trochanteric pain syndrome, tennis elbow, plantar fasciitis. Together called “Transarterial musculoskeletal embolization (TAME)”
Contraindications
Rheumatoid or infectious arthritis
Renal impairment (eGFR <45)
Acute knee injury requiring immediate surgical assessment.
Irreversible coagulopathy
Previous total or partial knee replacement in the concerned knee
Efficacy and alternatives
Conservative therapies should be trialed first, e.g, exercise, weigh loss, physical therapy
Medications - topical or oral NSAIDs, topical capsaicin, acetaminophen, duloxetine, and/or tramadol can be effective. Other medications and supplements are not well supported.
Surgical arthroplasty remains the gold standard but is a major operation with long recovery
Numerous minimally invasive treatment options such as steroid and hyaluronic acid injections can be temporarily effective though with limited data. Likewise, things such as acupuncture, manual or massage therapy, electrical nerve stimulation, laser treatments, and platelet-rich plasma injections have very limited data but may be helpful.
Genicular Artery Embolization - best data and insurance coverage
Heterogeneous methodology among prior studies including a few prospective single arm studies and two RCTs. Most patients have had moderate severity (KL grade 2-3) and measure improvement in terms of WOMAC or KOOS scores though with different definitions of success (e.g. reduction of 50% vs 16%). Embolics have included imipenem, permanent particles, lipiodol, and temporary particles. Generally promising results with minimal complications, good pain reduction, and improved QoL.
Review by Liu et al: 60% response rate at 12 months in terms of QoL and physical function but pain levels near baseline. RCT by Bagla et al: significant reduction in WOMAC and VAS pain scores at 12 months.
Pre-procedure work up
Radiographs within 3 months with KL grading for joints, e.g., kness, shoulders, and hips
Pre-procedural INR and platelet count for arterial access
Procedure steps and tips
(Optional) Place radiopaque marker on skin in area of greatest pain.
Obtain access, often femoral ipsilateral antegrade vs contralateral retrograde. Some use 5 Fr and others 4 Fr. Can also be done via radial and retrograde posterior tibial access.
Advance base catheter, e.g., Kumpe, Vert, or guide catheter for initial angiogram to map out vascular anatomy and assess for areas of synovial hyperemia.
NOTE: Synovial hyperemia may be less apparent on less selective runs.
GAE - Mid to distal SFA, 3 mL/sec for 18 sec
Hip - External iliac or CFA. Also need to assess internal iliac as the hip can have accessory supply from branches such as the inferior gluteal and obturator
Shoulder - Subclavian artery
Plantar fasciitis - Posterior tibial artery
Superselection of arteries supplying the area of hyperemia. Often requires 2.0 Fr or smaller microcatheter (e.g. average genicular artery is ~1.6 mm). A curved tip is also helpful such as a bern tip TruSelect (Boston Scientific).
GAE - Five main genicular arteries, descending genicular (often with early muscular/cutaneous branches), superior lateral and medial, and inferior lateral and medial genicular arteries. Sometimes the inferolateral synovium has supply from the anterior tibial recurrent artery course superiorly from the proximal anterior tibial.
Hip - Almost always branches of the lateral circumflex femoral artery, sometimes the medial circumflex femoral or branches of the internal iliac, particularly the inferior gluteal and obturator
Shoulder - Often branches of the suprascapular artery but highly variable and can include branches of the thoracoacromial, anterior circumflex humeral, or variants from the internal mammary, dorsal scapular, and vertebral
Plantar fascitis - Often calcaneal branches of the posterior tibial
Arteriography in the target vessel to confirm. This can reproduce the patient’s pain as further confirmation as can injecting some nitroglycerine.
If supply to overlying skin, and ice pack can be applied to minimize nontarget embolization.
Some also perform a cone beam CT either with initial less selective run and/or each superselective run.
(Optional) Nitroglyerine prior to embolization to enhance antegrade flow.
Embolization targeting pruning and vascular territory rather than complete stasis.
Embolic agents have varied with most studies using imipenem and cilastatin or small particles (e.g. EmboSpheres). Trend has been towards temporary embolic agents. E.g. a 1:3 contrast-lipiodol emulsion showed similar outcomes to imipenem and cilastatin (see LipioJoint-1 Trial). Many other temporary embolic agents are being trialed with potentially better safety profile than permanent beads.
Better outcomes with embolization of more genicular arteries, e.g., 3 or more rather than 1
Repeat arteriography to confirm end point and decreased synovial hyperemia.
Access closure.
Complications
Nerve injury, access site hematoma, non-target embolization.
Bone infarction observed 3-months post-procedural surveillance in non-weight bearing joint region
Transient post-procedural skin changes due to genicular arteries’ cutaneous branch non-target embolization
Post-procedure care and follow up
Some treat with methylprednisolone steroid taper and 500 mg naproxen BID for 5 days to alleviate short-term inflammation and pain.
Follow up clinic visits, e.g., at 1, 3, and 6 months post-op with repeat clinical scoring systems