Arterial
Key Publications and Resources
Procedure guide
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
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
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 - currently not FDA approved so often requires patients to pay out of pocket or be performed under a research trial
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, particles, and lipiodol. 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.
FDA approval will likely require comparative RCTs with longer follow up.
Knee radiographs within 3 months with KL grading
Pre-procedural INR and platelet count for arterial access
Obtain access, often ipsilateral antegrade vs contralateral retrograde. Some use 5 Fr and others 4 Fr
Advance base catheter, e.g., Kumpe, Vert, or guide catheter to mid to distal SFA for arteriogram to map out vascular anatomy and assess for areas of synovial hyperemia, e.g., 3 mL/sec for 18 sec. Synovial hyperemia may be less apparent on SFA/popliteal runs rather than superselection of geniculate arteries.
Superselection of geniculate arteries with microcatheter and microwire of choice.
DSA in each superselected geniculate artery assessing for synovial hyperemia and collateral supply to avoid nontarget embolization. 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. May enhance antegrade flow and reproduce knee pain.
Particle embolization targeting pruning and vascular territory rather than complete stasis.
Repeat arteriography to confirm end point and decreased synovial hyperemia.
Access closure.
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
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