Torn peroneal tendon

The tendon on the outside of the ankle becomes torn, causing lateral instability. This will result in swelling, pain and a sense of instability behind the outside of your ankle.

What is it?

The two peroneal tendons are elastic strips of tissue that connect the muscles in the calf (peroneal muscles) to the foot. The tendons run side-by-side in a groove at the back of the fibula (calf bone), and round the outer side of the ankle. One tendon runs under the foot and attaches near the arch. The other attaches to the outside of the midfoot.

These two tendons are responsible for moving the foot outwards. They are important tendons because they balance the ankle and the back of the foot and prevent the foot from turning inwards repetitively.

If a fracture is caused by twisting, the stabilising ligaments may also have been damaged, making dislocation or mis-alignment of the bones more likely - especially if you put weight on the ankle after the injury.

How does it feel?

Swelling, pain and a sense of instability behind the outside of your ankle.

Diagnosis

The surgeon will diagnose a peroneal tendon tear by carefully examining and palpating the outside of the ankle. An MRI scan will clearly document the extent of the tear.

Surgery

During arthroscopic surgery tendons with minor tears can be repaired by stitching them back together. If they are severely torn, they need to be replaced with new tendon tissue. Usually tendon tissue can be obtained from the thick achilles tendon in the same leg. It will be stitched onto the muscle and held in place on the bone with staples or small screws.

Recovery

For minor peroneal tendon tears, you should be able to put weight on your foot 48 hours after surgery. You will need physiotherapy for up to six weeks after this.
A tendon graft will take longer to heal. After surgery, you will wear a cast for up to six weeks after surgery, when you will transfer to a lightweight aircast walking boot. It may be 12 weeks before you are able to put full weight on the foot. Sports can be resumed after six months.

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