[Patellar Tendinopathy/Jumper's Knee] [Transarterial Microembolization (TAME)] Success Story Sharing

Author: Bow Wang, M.D.

Mr. W, 34 years old, is a professional soldier. Six months ago, after an exercise session, he experienced persistent pain in the lower front of his knee. Besides a pain score of 7 out of 10, he also experienced swelling and a burning sensation. The pain was particularly severe during exercise and climbing stairs.

Mr. W received treatment including rest, medication, acupuncture, shockwave therapy, injections, and rehabilitation, but the pain did not significantly improve. Finally, after consulting with Dr. Zhang Zhiwei, the head of orthopedics at National Cheng Kung University Hospital, he was diagnosed with patellar tendinitis/jumper's knee. He was then referred to the outpatient clinic of Bow Wang, M.D. at the National Cheng Kung University Hospital Interventional Medical Center for further discussion.

After discussing with Mr. W, Bow Wang, M.D. performed ultrasound and magnetic resonance imaging (MRI) examinations on his knee to confirm the diagnosis. Transarterial Microembolization (TAME) was also performed.

Under X-ray fluoroscopy guidance and local anesthesia, a microcatheter was inserted into the painful area via puncture of the femoral artery in the groin. During arterial angiography, contrast agent was injected to locate the disordered, capillary-like vessels proliferating in the anterior knee and patellar tendon region. Embolizing medication was then injected through the microcatheter to remove these abnormal capillary-like vessels (see the two images below).

Mr. W's knee pain improved on the day of treatment. Two weeks later, his pain score decreased from 7 to 2, and swelling and pain significantly improved.

There are many causes of anterior knee pain, one of which is patellar tendonitis, also known as jumper's knee.

The patella, commonly known as the kneecap, is located at the front of the knee. Patellar tendinitis/jumper's knee is inflammation and pain in the tendon connecting this bone to the tibia (shinbone).

Jumper's knee is generally classified as a sports injury. Many athletes (especially those involved in jumping sports such as basketball and volleyball) experience this condition, hence the name. It is caused by repeated straining or overuse of the patellar tendon at the lower edge of the knee. Symptoms include pain in the front of the knee, pain during exercise, and pain upon landing; it is often described as a burning pain. There are usually no obvious symptoms before exercise, but the pain worsens during or after exercise. Sometimes a bulge may appear at the front of the knee. Pain is most commonly felt at the lower edge of the patella upon palpation.

The cause is that the patellar tendon develops numerous microtraumas during repetitive jumping movements. These traumas to the muscle fibers result in disordered tissue and adhesions during the healing process, further leading to chronic inflammation of the tendon. Recent literature indicates that chronic inflammation is accompanied by disordered, proliferating capillary-like arterioles and associated pain nerves.

【Transarterial Microembolization (TAME)】achieves its effect by embolizing and clearing these disordered, proliferating capillary-like arterioles, thus reducing inflammation, swelling, and pain. However, Bow Wang, M.D. has limitations; its main indication is a pain index exceeding 5 points, and patients who have not shown significant improvement after more than three months of various traditional treatments.

This treatment is not suitable in the following situations:

1. Severe tendon or ligament damage or rupture

2. Poor kidney function (eGFR < 30 mL/min/1.73m2)

3. Low platelet count, abnormal coagulation function

4. The patient is unable to lie flat for two hours.

5. Pregnancy

Side effects of the treatment include local hematoma and bruising at the puncture site; temporary local discoloration at the embolization site, which will improve and disappear within minutes to one month.

It is recommended that patients undergo a detailed evaluation by a physician to confirm the true source of pain. After thorough discussion with the physician and family to understand the treatment process and related precautions, treatment should only be initiated for better assurance.