Posterior Ankle Impingement: Arthroscopic Treatment
Posterior impingement is pinching of bone or soft tissue at the back of the ankle when pointing the foot. Persistent cases are treated arthroscopically.
Posterior ankle impingement is pinching of bone or soft tissue at the back of the ankle between the shin bone and the heel bone when the foot points downwards (standing on tiptoe or kicking a ball). It is seen in athletes who point the ankle often and forcefully, such as ballet dancers, footballers, gymnasts and runners.
Causes
- Os trigonum: A small extra bone at the back of the talus in some people
- Stieda process: A long bony projection at the back of the talus
- Soft tissue that thickens after repeated strain or a sprain
- Tendinitis of the tendon that bends the big toe (FHL)
Symptoms
- Deep pain at the back of the ankle, in front of the Achilles tendon
- Pain that increases when rising on the toes, jumping or kicking
- Swelling at the back of the ankle
- Sometimes pain when moving the big toe
Diagnosis
Pain when the ankle is forced downwards is the typical finding. A side X-ray can show an os trigonum or bony projection. MRI and CT show the bone, soft tissue inflammation and tendon in detail.
Non-surgical treatment
At first, reducing painful movements, physiotherapy, pain relief and, in suitable patients, ultrasound-guided injections are tried. In athletes, technique and training load are adjusted.
Arthroscopic treatment
Posterior ankle arthroscopy is used when non-surgical treatment has not worked. The patient lies face down and a camera and instruments are introduced through small incisions on either side of the Achilles tendon. The os trigonum or bony projection is removed, pinched soft tissue is cleaned and the FHL tendon is released if needed. Thanks to the small incisions, recovery is usually faster than with open surgery.
Recovery
- Brief protection and controlled weight bearing in the first days
- Early movement exercises
- Return to daily activities within a few weeks
- Return to sport usually within a few weeks to a few months
Advice for athletes
For dancers and footballers, technique changes that avoid overloading the ankle when rising on tiptoe or kicking, together with calf and foot strengthening, reduce recurrence. After surgery, training load should be increased gradually.
Surgery or injection?
Ultrasound-guided injections can control symptoms for a long time in some patients and may be chosen as a temporary solution for athletes in mid-season. However, when a bony projection causes the impingement, symptoms often return and arthroscopic treatment is needed for a lasting solution.
Frequently asked questions
Does an os trigonum always cause pain?
No. Many people have an os trigonum without symptoms. Treatment is only needed if it causes pain.
Can I return to dance or football after arthroscopy?
Most athletes return to their previous level after completing rehabilitation. The time depends on the extent of the procedure.
Will there be scars?
The incisions are a few millimetres long, so the scars are very small.
When can I rise on tiptoe after surgery?
Controlled heel-raise exercises usually start after the first weeks and are progressed as strength improves.
The information on this page is general and does not replace an examination. An examination is needed to decide which treatment suits you.