Genicular artery embolization ‘highly effective’ in reducing knee OA pain
Genicular artery embolization is safe and “highly effective” in reducing symptoms of moderate to severe knee osteoarthritis in patients who have been unresponsive to other conservative therapy, according to data.
“When we talk about the treatment options for knee OA, I think most of us are familiar [with] two categories — either you do nothing and rest up your knee or you can take medications, such as Tylenol or ibuprofen — and that works for the majority of people, although it’s relatively temporary,” Siddharth A. Padia, MD, FSIR, a professor of radiology at UCLA and lead author of the study, said during a press briefing that highlighted findings to be presented at the Society of Interventional Radiology Annual Scientific Meeting.
“When those stop working, many people will get joint injections — typically a steroid, such as cortisone, or a gel,” he added. “A typical joint injection lasts from anywhere from 1 to 3 months, so it is not built as a long-term solution. Currently, the only long-term solution is knee replacement, which does work, and it is recommended for people with severe, symptomatic OA, but the challenge with total knee replacement is that it does involve anesthesia, a hospital stay and a prolonged recovery and rehabilitation time.”
Genicular artery embolization, on the other hand, is a procedure performed by interventional radiologists that reduces pain and symptoms by decreasing inflammation. This is done by slowing down, or embolizing, blood flow in the knee, Padia said.
The outpatient procedure takes 2 hours to complete. It does not require general anesthesia, but uses conscious sedation through an IV and a numbing anesthetic at the fold of the knee. A small catheter is inserted into the blood vessel in the leg and guided via X-ray into the knee. Contrast dye is injected. An angiogram is performed.
Identify artery branches
The resulting angiogram then allows providers to locate specific branches of the artery that are abnormally inflamed. A small amount of embolization particles is then injected into the area, reducing inflammation.
“It’s this inflammation in the knee joint that causes people’s pain and physical dysfunction,” Padia said. “In theory, if we can reduce the inflammation, we can make people’s pain go away and make their function overall improved.”
To analyze the safety and efficacy of this procedure in patients with symptomatic knee OA, Padia and colleagues conducted a prospective, single-center, open-label study. The researchers enrolled 40 adults aged 40 to 80 years with radiographic knee OA and moderate or severe knee pain, who had no prior knee surgery and were either not candidates for, or unwilling to receive, future surgeries. Participants were also required to have been unresponsive to conservative treatment, including NSAIDs or joint injections.
Technical success in 100% of patients
The researchers studied participants’ baseline pain through the VAS and their symptom scores via WOMAC. Genicular artery embolization was performed in all participants using 100 m particles (Embozene, Varian), injected into one to three arteries associated with the location of the patient’s pain. Padia and colleagues assessed adverse events and symptom scores at 1 week, 1 month, 3 months, 6 months and 1 year following the procedure.
Technical success was achieved in 100% of participants. Among patients, temporary skin discoloration and mild knee pain following the procedure were common and expected. Treatment-related adverse events included a groin hematoma requiring overnight observation in one patient, self-resolving focal skin ulceration in seven patients and asymptomatic small bone infarction identified with MRI in two patients.
At 12 months, median WOMAC scores decreased 60% from 52 to 21. Baseline pain scores decreased 63% during the same time, from a median of 8/10 to 3/10. Among participants, 67.5% experienced greater than 50% reduction in WOMAC scores and 70% demonstrated greater than 50% reduction in pain scores.
“Based on the conclusions of this trial, we have the potential to completely disrupt and change the way patients with knee OA are treated,” Padia said.
Editor’s note: The evidence-based initial treatment for OA of the knee includes avoidance of aggravating activities, exercise to maintain motion and strength, weight loss, and acetaminophen and/or NSAIDs for discomfort. – Anthony A. Romeo, MD, Chief Medical Editor, Orthopedics Today
- For more information:
- Siddharth A. Padia, MD, FSIR, can be reached in the department of radiology at UCLA, 757 Westwood Plaza, Floor 1, Los Angeles, CA 90095; email: firstname.lastname@example.org.