What is an ankle sprain?
Ankle sprains are one of the most common injuries in society, and occur when you suddenly fall or twist the joint, or land in an awkward position after a jump. They result in pain, swelling, tenderness, bruising, stiffness, and an inability to bear full weight through the ankle.
A sprain means the stretching or tearing of the ligaments which connect two adjacent bones together. Because these ligaments stabilise the joints, tearing of the ligaments can lead to acute or chronic joint instability (giving way). The most common sprain occurs to the lateral ligaments, on the outside of the ankle.
Some individuals are predisposed to spraining their ankles. They’re more common in people with hindfoot varus, which is when the heels are turned inwards, since this makes it easier to turn over on the ankle. People with ligamentous laxity (double jointed) are also more prone to sprains.
What anatomy is injured in an ankle sprain?
There are several ligaments around the ankle. The lateral ligaments are more commonly sprained than the medial ligament (the deltoid). The lateral ligament complex is made up of:
- The ATFL, or anterior talo-fibular ligament, which connects the tip of the fibula to the front of the talus. This ligament is the most commonly sprained of all the ankle ligaments.
- The CFL, or calcaneo-fibular ligament, which connects the tip of the fibula to the calcaneus (heel bone). The is usually injured after the ATFL.
- The PTFL, or posterior talo-fibular ligament, which connects the tip of the fibula to the back of the talus. It is unusual to tear this ligament, and when it occurs this represents a severe ankle injury.
A lateral or medial ligament sprain is quite different to a high ankle sprain, which is when the syndesmosis ligaments between the tibia and the fibula, just above the ankle joint, are torn.
How is an ankle sprain diagnosed?
The diagnosis of an ankle sprain is usually made from the history of the injury and physical examination of the ankle. X-rays of your ankle may be needed to confirm if a fracture is present.
It is important not to regard every ankle injury as a simple sprain though, because other injuries can occur at the same time. For example, fractures of the ankle bones often occur in tandem with sprained ligaments, along with fractures of the 5th metatarsal or anterior process of the calcaneus. Peroneal tendons can be damaged or torn with a severe sprain, and in some cases the articular cartilage of the ankle joint can be damaged. Whilst an MRI is not usually required to diagnose a sprain, it is sometimes needed to rule out other problems in the ankle.
How is an ankle sprain treated?
Most sprains can be treated non-operatively, and the ligaments generally heal very well. The most common initial treatment recommended for ankle sprains is rest, ice, compression and elevation (RICE).
- Rest: You should not move or use your ankle in order to reduce pain and prevent further damage. Crutches may be needed initially.
- Ice: An ice-pack should be applied over the injured area for 20 minute periods several times a day, for up to 3 days after the injury. You can use a cold pack or crushed ice wrapped in a towel. Never place ice directly over the skin. Ice packs help reduce swelling and relieve pain.
- Compression: Compression of the injured area helps to reduce swelling and bruising. This is usually accomplished by using an elastic wrap (eg tubigrip) for a few days or weeks after the injury.
- Elevation: Place the injured ankle above the level of your heart to reduce swelling. The more time you elevate the injured limb, the quicker the swelling will come down.
If you can walk after a sprain, then immobilisation usually isn’t necessary. In more severe sprains where you cannot bear weight, a period of time in a boot can help. Anti-inflammatory pain medications may be prescribed to help reduce the pain and control inflammation.
Physiotherapy is very important for rehabilitation. You will need to strengthen the supporting muscles around your ankles, in particular the peroneal muscles which prevent inversion of the foot. Sometimes an ankle brace is needed during sport until the muscles are strong enough to play without it.
Surgery is sometimes required for patients with high-grade ligament tears or chronic instability. This usually involves a repair of the torn ligaments using the Brostrom-Gould procedure. This involves using small anchors in the bone which have sutures attached to them, and stitching the ligaments back to the bone. In some cases the ligaments cannot be repaired, and a reconstruction is required with transfer of a tendon from somewhere else in the body (eg a hamstring tendon) to recreate the ligaments.
Surgery can also be required when cartilage or other structures around the ankle are damaged.
How long will it take to recover?
Mild sprains recover the quickest, and people can often return to sports within several days. More severe sprains take longer, and sometimes require many weeks off sports. High ankle sprains are different than lateral or medial ankle sprains, and take considerably longer to heal.
What if you suffer from repeated sprains?
The more times you sprain your ankle, the more likely you are to damage cartilage inside the ankle joint. Chronic instability should not be ignored, and it’s best to seek specialist advice from a foot and ankle orthopaedic surgeon.