Can you give a brief summary of genicular artery embolisation for a patient over 50 years old with refractory knee osteoarthritis pain who is not a candidate for, or wishes to avoid, total knee arthroplasty?

Genicular Artery Embolization for Knee Osteoarthritis

Genicular artery embolization (GAE) is an investigational minimally invasive procedure that should only be considered after exhausting all guideline-recommended treatments for refractory knee osteoarthritis, and patients must be explicitly informed of its non-guideline status. 1

Current Guideline Status

• No major guideline society, including the American College of Rheumatology or American Academy of Orthopaedic Surgeons, recommends GAE for knee osteoarthritis due to lack of established evidence. 1
• GAE remains investigational and should not be presented as an equivalent alternative to established treatments 1

Required Treatment Hierarchy Before Considering GAE

First-Line Core Treatments (Must Be Attempted)

• Exercise therapy (cardiovascular and resistance land-based programs), weight loss for overweight patients, and patient education 1, 2
• Aquatic exercise programs 2
• Minimum 3-6 months trial of conservative management 2

Second-Line Pharmacologic Options (Sequential Trials Required)

• Acetaminophen, topical NSAIDs, oral NSAIDs, and intra-articular corticosteroid injections 1
• Intra-articular corticosteroids provide short-term benefit (1-4 weeks) but not sustained relief at 12-24 weeks 3

Third-Line Options for Inadequate Response

• Duloxetine 60 mg daily for inadequate response to first-line treatments 1
• Tramadol, acupuncture, or TENS for refractory cases 1

GAE Mechanism and Technical Overview

Pathophysiologic Rationale

• GAE targets abnormal neovascularization and synovial inflammation in osteoarthritic knees by selectively embolizing hyperemic genicular arteries 4, 5
• The procedure arrests neoangiogenesis and prevents pathological neoinnervation underlying the inflammatory cascade 6

Technical Procedure

• Outpatient minimally invasive procedure identifying and embolizing 1-2 abnormal hyperemic genicular arteries using 75-μm spherical particles 7
• Median embolic material volume approximately 4.3 mL 7
• Technical success rates approach 100% in reported series 8, 7

Clinical Evidence Summary

Efficacy Data

• Short- to mid-term studies show pain reduction with improved VAS, WOMAC, and KOOS scores 8
• One pilot study demonstrated VAS improvement from 73 to 38 at 6 months post-procedure 7
• KOOS pain scores improved from 43.6 to 64.6 at 6 months 7
• 55% of patients achieved minimal clinically important change in pain at 6 months 7

Safety Profile

• Adverse events are generally mild and self-limited 8
• Self-limited skin discoloration occurs in approximately 42% of patients 7
• Temporary pain increase (>20 points on VAS) requiring 1 week of analgesics occurs in 30% of patients 7

Critical Limitations and Caveats

Evidence Gaps

• Long-term safety and durability data beyond 6-12 months are lacking 6
• No standardized protocols exist for vessel targets, embolic agent size, or periprocedural management 8, 6
• No comparative effectiveness trials against established treatments 6
• Optimal patient selection criteria remain undefined 5, 6

Appropriate Patient Population (If Considered)

• Patients over 50 with mild-to-moderate knee osteoarthritis who have persistent symptoms despite exhausting all guideline-recommended conservative treatments 4
• Not candidates for total knee arthroplasty due to comorbidities or patient preference 4
• Must have documented failure of exercise therapy, weight management, pharmacologic options, and intra-articular injections 1, 4

Critical Pitfalls to Avoid

• Never delay total knee arthroplasty in appropriate surgical candidates by offering GAE 1
• Never present GAE as first-line or second-line treatment 1
• Never offer GAE without explicit informed consent about its investigational status and lack of guideline support 1
• Avoid GAE in patients who have not completed adequate trials of all guideline-recommended treatments 1, 2

Comparison to Established Surgical Option

• Total knee arthroplasty remains the definitive treatment for severe knee osteoarthritis with refractory pain and disability, showing 89% good-to-excellent outcomes for pain and function up to 5 years 3
• TKA is safe and effective in improving quality of life, reducing pain, and improving function based on extensive observational data 3