Background and study aims

Every year more than 150,000 people suffer from pain at the back of the heel, leading to walking difficulties. The most common cause of this is Achilles tendinopathy, also known as Achilles tendonitis. Achilles tendinopathy is a condition where the Achilles tendon becomes damaged, causing pain, swelling and stiffness. The Achilles tendon is a very strong band of tissue which connects the calf muscle to the heal bone. There are two main areas that are affected, the middle of the tendon (mid-substance Achilles tendinopathy) and where the tendon meets the heel bone (insertional Achilles tendinopathy). Mid-substance Achilles tendinopathy is thought to happen when the tendon is unable to repair itself after it has been injured. Currently, the main treatments for Achilles tendinopathy involve a combination of self-help techniques, physical therapy, medications and even surgery, although the most effective treatment is widely debated. Platelet rich plasma (PRP) is a part of the blood plasma (the liquid part of the blood) with a high platelet concentration. Platelets are blood components which play an important role in the healing process. The aim of this study is to find out whether injections of PRP can help to speed up healing and reduce pain in patients with mid-substance Achilles tendinopathy.

Who can participate?

People aged 18 or over, who have been suffering from painful Achilles tendons for more than three months.

What does the study involve?

Participants are randomly allocated to one of two groups. Those in the first group have a blood sample taken, which is spun in a machine to separate out the components of the blood. The PRP is then injected into the skin near the painful tendon. Participants in the second group are given a placebo (imitation) injection into the skin near the painful tendon. At the start of the study and then again after three and six months, participants in both groups complete questionnaires in order to find out whether there has been any change to their pain levels and ability to perform activities.

What are the possible benefits and risks of participating? Participants may benefit from reduced pain due to the PRP injection. Risks of of participating are minor, however participants may experience pain, swelling or bleeding, skin discolouration and possible allergic reaction to the PRP injection.

Where is the study run from?

NHS hospitals in England (UK)

When is the study starting and how long is it expected to run for?

June 2016 to January 2019

Who is funding the study?

Arthritis Research UK (UK)