Ankle syndesomosis injury is otherwise known as a high ankle sprain, as it occurs just above the ankle where the long bones in the bottom of the leg, the tibia and fibula meet. There are three ligaments at the ankle as well as a fibrous membrane that runs in between the tibia and fibula that maintain the integrity of the joint. When any of these ligaments are overstretched or torn, this leads to instability of the ankle joint, and in some cases, a widening of the space between the tibia and fibula.
The injury usually occurs by one of two ways: 1) When the foot is forced into excessive outward rotation, while the leg remains fixed, 2) When the ankle is loaded severely and is pushed into excessive dorsiflexion (toe down position) while the joint is loaded. These injuries are most often seen in contact sports involving quick changes of direction such as basketball, soccer, football and skiing.
Symptoms of a Syndesmosis Injury
- A syndesmosis injury can feel like a very severe ankle sprain.
- There may be bruising and swelling high at the ankle joint rather than on the outside of the foot.
- Pain when going down stairs and when turning the foot out.
- Turning or twisting the foot results in sharp pain to the ankle.
- The ankle may feel unstable due to widening of the ankle mortise due to over-stretching of the ligaments.
- Ankle weakness.
- Inability to place weight on the leg.
- Calf pain.
Initial management of syndesmosis injury is to relieve pain and reduce inflammation through the use of: rest, ice, compression, elevation as well anti-inflammatory medications. An X-ray may be required to identify how stable the joint is. With relatively stable (grade 1 & 2 injuries), crutches and taping or a boot are used for a short period to offload the joint and to allow tissue healing. Your physiotherapist will provide you with rehabilitation exercises aimed at regaining normal joint range of motion, strength, balance, proprioception and normal foot biomechanics. Return to sport time frames are dependent on the degree of damage to the area.
In more severe cases (grade 3 injury), where there is significant instability of the joint or additional fractures, surgical fixation may be required to stabilise the joint. A review with a consultant to discuss the best course of management is advised. If surgical intervention is required, rehabilitation will take place after surgery with the same goals as for a grade 1 & 2 injury above. This type of injury can take up to 6 months to heal.
Widening of the ankle joint by 1mm reduces the tibiotalar contact area by 42%, which can lead to instability and predispose you to early osteoarthritis of the joint if the injury is not managed effectively. Early detection and management is vital in syndesmosis injury.