What is posterior ankle impingement?
Posterior ankle impingement is a condition in which pain develops at the back of the ankle when the foot is forced downwards.
Why does it occur?
It usually occurs when there is an extra bone at the back of the ankle (os trigonum- see image right), this then becomes trapped at the back of the ankle when the foot is forced downwards and is therefore common in dancers. The extra bone becomes inflamed, as does the surrounding soft tissue. The tendon that passes to the big toe lies next to this extra bone and any damage to this tendon can lead to similar symptoms.
What symptoms does it cause?
Pain: at the back of the ankle when the foot is forced downwards i.e. when dancing ’en pointe’, walking down hills or stairs, or when running. As with other causes of pain in the ankle they can lead to a sensation of instability or insecurity. If the tendon to the big toe is damaged or inflamed then pain and a cracking sensation may occur when attempting to bend the big toe.
What options are there for treatment?
Simple pain killers may be sufficient to reduce the symptoms to an acceptable level.
These may be appropriate in some cases, it can help to confirm the diagnosis and may help to reduce the symptoms.
The extra bone and any scar tissue can be removed using key hole techniques (see: Hindfoot Endoscopic Surgery), occasionally open techniques are required using a bigger incision in the skin.