Ankle fractures can involve the bump of bone on the outside of the ankle (lateral malleolus), which is the end of the smaller leg bone in the lower leg (fibula). Or they can involve the bump on the inside of the ankle (medial malleolus), which is the end of the larger leg bone (shinbone, or tibia), or the back lower end of the shinbone (posterior malleolus) or, more often, both.
- The ankle may fracture in more than one place, and the ligaments that make the ankle stable may be torn.
- A fractured ankle is painful and swollen and usually cannot bear weight.
- Doctors suspect an ankle fracture based on symptoms and physical examination but take x-rays to confirm it.
- Stable fractures of the fibula are treated with a walking boot or cast, and most fractures of the tibia require surgery.
(See also Overview of Fractures.)
Ankle fractures are common. The ankle may fracture when the foot is forced up or down or rolls in or out. The ankle may fracture in more than one place. Sometimes the top of the fibula (near the knee) is also fractured.
The ankle joint consists of three bones:
- The two bones of the lower leg (fibula and tibia)
- A bone in the foot (talus) located between the leg bones and the heel bone
These three bones are connected by several ligaments, which form a ring and make the ankle stable. Fractures often disrupt the ring in more than one place. For example, if one of the bones is fractured, a ligament is often severely torn at the same time. If a fracture disrupts two or more structures in the ring, the ankle is unstable.
Sometimes when force is applied to a ligament in the ankle, the ligament breaks off a small chip of bone at the point where the ligament attaches to the bone. This type of fracture, called an avulsion fracture, may feel more like a severe sprain rather than a broken bone.
Anatomy of the Ankle
A fractured ankle is painful and swollen. Usually, people cannot put their weight on the injured extremity.
- A doctor's evaluation
(See also Diagnosis of Fractures.)
To check for fractures, doctors examine and gently feel (palpate) the ankle. If they suspect a fracture, they take several x-rays to confirm (or rule out) the fracture.
Based on results of the examination and x-rays, doctors determine whether the ankle is stable or not. Then they can determine the best treatment.
- For most stable fractures, a walking boot or cast
- For unstable fractures, sometimes surgery to realign the broken bones
For most stable ankle fractures (including avulsion fractures), doctors usually provide a walking boot or apply a cast, which is worn for about 6 weeks. A walking boot has Velcro fasteners and a rigid frame and shell to protect the foot from further injury. Stable ankle fractures usually heal well.
For unstable ankle fractures, surgery may be required. Usually, open reduction with internal fixation (ORIF) is done. In ORIF, the broken bone fragments are put back in place (reduced) and then held in place using a devices such as metal wires, pins, screws, rods, and plates. After an unstable ankle fracture, the ankle may not be as strong as before.
If the ankle is stable and the bone fragments are put back in place correctly, the fracture usually heals well. If the bone fragments do not remain in place, arthritis may develop, and the ankle may fracture again.
© 2020 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Merck Manual Disclaimer