Unstable Ankle

Most commonly unstable ankle starts after an episode of injury, usually an ankle sprain. The main question is whether the ankle ligaments are slack and the ankle therefore mechanically unstable. This can be diagnosed by comparing how stable the injured ankle is compared with the other ankle.

It is possible that the ligaments may be mechanically normal but the ankle nevertheless feels unstable. This is called functional instability because the ankle joint cannot be demonstrated to be unstable by examination.

There are various causes for this either originating from inside or outside of the ankle joint. Within the joint inflamed soft tissue resulting from the injury known as synovitis or an injury to the joint lining may lead to pain / reflex spasm in certain positions of the foot. An injury outside the ankle joint to the peroneal tendons can also be responsible.


Ankle physiotherapy concentrating on soft tissue massage, a range of exercises and peroneal muscle strengthening may be helpful. However if instability continues despite ankle physiotherapy treatment then surgery is indicated.


The aim of the ankle surgery is to restore the length of the elongated ligaments and is carried out, through a small incision approximately 2cm long.


You will wear an ankle brace for the first six weeks following ankle surgery and physiotherapy commences two weeks post-operatively.