The ankle joint comprises three bones: the tibia, fibula, and talus. The ends of the fibula and tibia (lower leg bones) form the lateral (outer) and medial (inner) malleolus respectively, and together they form a mortise under which the talus sits. The joint is protected by a fibrous membrane called a joint capsule, and filled with lubricating synovial fluid to enable smooth movement.
Ankle injuries are very common in athletes and in people performing physical work, often resulting in severe pain and impaired mobility. Pain after ankle injuries can either be from a torn ligament (an ankle sprain) or from a broken bone (an ankle fracture). Ankle fractures are painful injuries where there is a break in one or more bones forming the ankle joint. The ligaments surrounding the ankle joint are also often injured when an ankle fracture occurs, and the cartilage inside the joint can sustain damage as well.
Ankle fractures occur from excessive rolling and twisting of the ankle, usually in an accident or during activities such as jumping or falling.
With an ankle fracture, there is immediate swelling and pain around the ankle as well as impaired mobility. In some cases, blood may accumulate inside the joint, a condition called haemarthrosis. In cases of severe fracture, deformity around the ankle joint is clearly visible, and parts of bone may protrude through the skin.
Types of fractures
Ankle fractures are classified according to the location of the fracture and the mechanism of injury. Some different types of ankle fractures include:
- Lateral malleolus fracture in which the outer part of the ankle is fractured.
- Medial malleolus fracture in which the inner part of the ankle is fractured.
- Posterior malleolus fracture in which the posterior part of the tibia is fractured.
- Bi-malleolar fractures in which both lateral and medial malleoli are fractured
- Tri-malleolar fractures in which the lateral, medial, and posterior malleoli are all fractured.
- Syndesmosis injuries, also called high ankle sprains, are sometimes associated with certain fracture patterns.
The diagnosis of the ankle injury starts with a thorough physical examination, followed by X-rays of the injured area. Usually it is very difficult to differentiate a broken ankle from other conditions such as a sprain, dislocation, or tendon injury without having an X-ray of the injured ankle. In some cases, pressure is applied on the ankle and then special X-rays are taken. This procedure is called a stress test. This test is employed to check the stability of the fracture to decide if surgery is necessary or not. In complex cases, where detailed evaluation of the bones or ligaments is required, a CT or MRI scan is organised.
Immediately following an ankle injury and prior to seeing a doctor, you should apply ice packs and keep the foot elevated to minimize pain and swelling.
The treatment of an ankle fracture depends upon the type and the stability of the fractured bone. Treatment starts with non-surgical methods, and in cases where the fracture is unstable and cannot be re-aligned, surgical methods are employed.
In non-surgical treatment, the ankle bones are re-aligned and special boots or a plaster cast is placed around the leg and ankle, usually for around 6 weeks.
With surgical treatment, the fractured bones are accessed by making an incision over the ankle area, the bones are put back in place, and specially designed plates and screws are used to stabilise the fracture. The incision is then sutured closed and the operated ankle is immobilised with a splint or cast.
After ankle surgery, you will be given specific instructions on weightbearing. After surgical stabilisation of certain fractures, some weight bearing is allowed. More severe fractures require 6 weeks of non-weight bearing.
Physical therapy of the ankle joint is usually commenced as soon as the wounds have healed. It generally takes 2-3 months for the fractures to heal, after which patients may be able to perform their normal daily activities.
Risks and complications
Risks and complications that can occur with ankle fractures include blood clots in the leg (DVT), stiffness, long term pain, the bones not healing in the correct position, and sometimes not healing at all. Ankle fractures can also lead to post-traumatic arthritis in the future. These risks are minimised when fractures are anatomically fixed and early post-operative rehabilitation is begun.