In a recent study, researchers at the New York University Grossman School of Medicine used genicular artery embolization (GAE) as a treatment for knee osteoarthritis. According to Featured Abstract 112, “Genicular Artery Embolization for Treatment of Knee Osteoarthritis: A Prospective Pilot Trial” (which will be presented on Monday, March 6, at 3 p.m. in Room 222C of the Phoenix Convention Center), GAE is a safe and efficacious treatment option for patients with knee osteoarthritis.
“We’re seeing significant reduction in knee pain and improvement in stiffness, quality of life and function,” said presenter Bedros Taslakian, MD, director of VIR research program and clinical research integration at the NYU Grossman School of Medicine.
When the researchers designed this project in mid-2019, there were only three published studies on GAE for knee osteoarthritis, Dr. Taslakian said. “These publications showed significant reduction in knee pain, promising clinical outcomes and low complication rates. So we wanted to add something new to the known literature.”
Collaborating with a team of rheumatologists, orthopedic surgeons and musculoskeletal (MSK) radiologists, Dr. Taslakian’s team took the existing research a step further by studying disease-specific biomarkers.
“We wanted to evaluate the role of GAE as a possible disease-modifying treatment option for knee osteoarthritis by studying these disease-specific biomarkers,” said Dr. Taslakian. “It is known from the rheumatology and orthopedic surgery literature that these biomarkers correlate with disease severity and with the clinical and radiographic progression of osteoarthritis.”
Additionally, researchers used a new method for evaluating clinical success: minimal clinically important difference (MCID), which uses the patient’s percentage reduction of pain.
“Often researchers evaluate averages, and that’s the statistical significance part of evaluating your outcome,” said Dr. Taslakian. “Using MCID thresholds actually bridge the gap between statistical significance, which remains important, and the clinical significance, which is actually important to patients and practicing physicians. We wanted to introduce this concept because after achieving at least the MCID threshold is when patients actually feel the benefit of the procedure or a treatment, specifically when it's related to pain treatment.”
The percentage reduction of pain required for a patient to feel the clinical difference, in this case pain reduction, varies in a range of 10–30%, but these thresholds are largely based on data from the surgical literature, Dr. Taslakian said. In the future, he hopes to research procedure-specific MCID levels.
The investigators defined clinical success as a 21% decrease in pain score using The Western Ontario and McMaster Universities Arthritis Index model, which was evaluated 1 year after the procedure. Of the study’s 13 patients at the time of the abstract submission, technical success was achieved in 100% and clinical success (defined as at least 21% reduction in WOMAC pain score) was achieved in 75%. No major adverse events occurred.
One central finding, Dr. Taslakian said, is the decrease in hyaluronic acid levels.
“I think the most significant finding is that we saw some statistically significant reduction in hyaluronic acid levels, a marker that is known to be associated with morphological progression of knee OA and radiographic severity of the disease. Serum hyaluronic acid levels decreased from 94 ng/mL at baseline to 52 ng/mL at 12 months with a P value of 0.022,” he said. The other disease-specific biomarkers are also declining but have not reached statistically significant levels yet. According to Dr. Taslakian, this is likely because only five patients were included in the preliminary analysis, as the biomarkers are largely evaluated at 12 months.
From the preliminary findings, the researchers are hopeful that GAE can have an impact on the progression of osteoarthritis.
“I believe if we show reduction or even stability in the levels of the biomarkers, this pilot trial may well suggest that GAE can potentially be a disease-modifying treatment option for knee osteoarthritis beyond its role in managing symptoms, which completely changes the game,” said Dr. Taslakian. “Osteoarthritis is a progressive disease—every year is worse than the prior year. If we delay disease progression or stop it at that level, it would be significant.”
