Ankle impingement develops if a bony growth at either the front or rear part of the ankle bone forms where it connects with the shin bone. This growth disrupts with the normal range of motion of the ankle.
This can occur anteriorly where it affects the front part of the ankle or posteriorly which affects the rear part depending on where the bony growth develops. The impingement can often form after an ankle sprain that fails to properly heal.
Indications
Anterior impingement
- Pain felt at the front region or side of the ankle that does not settle after an ankle sprain has healed
- Ankle seems weakened
- Pain is produced by forcing or passively moving the ankle into dorsiflexion or pointing the foot upwards to extend the muscles at the rear part of the leg.
Posterior impingement
- Pain felt at the rear part of the ankle
- Tenderness can be felt at the back of the lower tip of the fibula
- Pain is aggravated after movement when the foot is directed downwards into plantar flexion position where the foot is pointed downwards.
- Going up on tiptoes triggers pain
- Presence of bone spurs on the heel bone and shin bone on an X-ray
What are the causes of ankle impingement?
The tissues within the ankle joint can be trapped in between the ankle bones. This is called as impingement and likely to occur if the ankle is completely flexed upwards or downwards.
For posterior impingement at the back part of the ankle, it is quite common among ballet dancers and caused by a bony protrusion at the rear of the ankle.
Anterior impingement can develop from a severe or repeated ankle sprain as the ligaments thicken and end up compressed amidst the bones. As the ruptured or torn ligament recuperates, the body forms excess scar tissue along the front and at the sides of the joint which leads to a meniscoid lesion.
Management
The individual should rest for up to 4 weeks. A splint or plaster cast might be fitted to limit movement of the ankle. Application of ice is also beneficial in reducing the pain and inflammation.
The doctor will prescribe non-steroidal anti-inflammatory drugs (NSAIDs). In case conservative measures fail, surgery might be an option.