What is a high-volume Achilles tendon injection for Achilles tendinopathy?
Achilles tendinopathy refers to inflammation of the Achilles tendon. Achilles tendon issues can be categorised into insertional (lower down) and non-insertional (mid-portion) problems. Please see our article to learn more about Achilles tendinopathy. In cases where conservative management and physiotherapy fail to produce results, a high-volume Achilles tendon injection may be recommended.
How is ultrasound-guided high-volume Achilles tendon injection done?
Your doctor will speak to you on the day of the procedure. It involves injecting a high volume of sterile (clean) water with numbing medications and sometimes low-dose steroids accurately under ultrasound guidance to separate the Achilles tendon from the deep fat pad. Achilles tendinopathy is often accompanied by a process called neovascularisation, where small new blood vessels and nerves develop in the Achilles tendon and the fatty tissue deep to it. High-volume Achilles tendon injection disrupts these new vessels and nerves, with evidence showing good results in terms of pain reduction and improvement in overall function. The procedure is done under ultrasound guidance to ensure accuracy. There is significant evidence that ultrasound-guided injections result in superior results compared to non-guided injections.
You will usually be asked to lie on your tummy on the examination table. The doctor will assess the area using ultrasound to determine the best approach. Then the skin will be cleaned and prepared at the injection site, and numbing medication will be administered to the skin using a small needle. Then, a needle will be accurately advanced into the interface between the deep surface of the Achilles tendon and the underlying fatty tissue, and the injectate will be used to separate the two.
What to expect during/after the procedure?
You may feel a gradual build-up of pressure at the lower calf. This is expected as the procedure involves injecting a reasonable volume of fluid. Your doctor will keep checking on you during the procedure. When the procedure is done, your calf might feel swollen/tight for a few days. A small plaster is usually applied to the site of injection. You can remove this later during the same day. You can eat and drink normally before and after the procedure. You can shower as usual but avoid very hot showers/steam rooms. You can use simple painkillers like paracetamol if you experience pain at the injection site. It’s advised not to drive immediately after the procedure. Resting the area and avoiding extraneous activities after the procedure are important, as instructed by the orthopaedic surgeon.
What are the possible complications of ultrasound-guided high-volume Achilles tendon injection?
The complications are rare in general. These include:
Pain, swelling and discomfort for a few days at the procedure site.
Infection. This is very rare but important to be aware of. Signs of infection include pain, redness, swelling and hotness at the injection site. Sometimes you may also notice a fever. Infection is very rare and reported in less than 1:10000 cases. You need to seek urgent medical attention if you develop signs of infection.
Small risk of weakening of the Achilles tendon. Therefore, adequate resting of the ankle, as advised by the orthopaedic surgeon, is very important following the procedure. In some cases, you might need to use a special boot for a short period to reduce the load upon the Achilles tendon.
How long does ultrasound-guided high-volume Achilles tendon injection take?
The length of the procedure depends on the difficulty of the case and the experience of the doctor. Usually, 30 minutes is a reasonable time for the whole procedure (including explanation and preparation).
Is ultrasound needed for a high-volume Achilles tendon injection?
Ultrasound is very useful in the assessment of the Achilles tendon. First, it will confirm the diagnosis and assess whether the changes are insertional or affect the tendon's mid portion, as the management is different. It will assess the degree of changes and if there is any tear within the tendon. It will also assess any new vessel formation within the tendon and the deep fat pad. If this is present, an ultrasound-guided high-volume injection can be useful for the treatment. Ultrasound will also assess for the presence of any heel bursitis, which can be seen in association with insertional Achilles tendon problems.
Do steroids help in Achilles tendinopathy?
Administering steroids during a high-volume Achilles tendon injection procedure can be considered. Steroids are potent anti-inflammatory medicines that can be directly injected into the area of inflammation under ultrasound guidance to reduce pain and inflammation. Evidence shows that the pain relief following steroid injections in Achilles tendinopathy is short-lived, lasting for an average of 12 weeks, with no significant difference in the long-term effect compared with procedures without a steroid injection. The Achilles tendon is a primary load-bearing tendon, and the main concern with injecting steroids around the tendon is the increased risk of tendon rupture, although the risk is very small. Therefore, the decision to include corticosteroids in the injection will be made after careful discussion with the patient.
Foot & Ankle conditions and treatments