May also be called: Lateral Malleolar Fracture A lateral malleolus (muh-LEE-uh-lus) fracture is a type of broken ankle that happens when part of the fibula just above the ankle joint fractures. More to Know The bony knobs on the inside and outside of the ankle are called the malleoli, which is the plural form of malleolus. The knob on the outside of the ankle, the lateral malleolus, is the end of the fibula, the smaller bone in the lower leg. When this part of the bone fractures, or breaks, it's called a lateral malleolar fracture. This type of fracture can be caused by twisting of the foot and ankle, a trip or fall, or a direct blow to the ankle. Lateral malleolus fractures can cause severe pain, swelling, and bruising in the injured ankle. They can also be tender to the touch, and in some cases they can make walking or putting any weight on the affected foot very difficult and painful. The lateral malleolus can fracture at a number of different levels, and treatment often depends on where the fracture is located. If the broken bone is not out of place and the ankle is stable, treatment may consist of just wearing a special boot or cast to immobilize the ankle as it heals. In some cases, though, surgery has to be performed to align the bone and hold it together with metal plates, rods, or screws. In general, it takes at least 6 weeks for the broken malleolus to heal. Keep in Mind A lateral malleolus fracture usually requires the person to keep weight off the affected foot for a few weeks. In most cases, people return to normal daily activities within 3 to 4 months. Stretching and strengthening exercises supervised by a doctor or physical therapist can help improve ankle function and mobility during the healing process. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles A to Z: Fracture, Bimalleolar Learn about types of lower extremity fractures and conditions that can affect the ankle and lower leg. Read More Ankle Sprains A sprained ankle is a very common injury that happens when the ligaments that support the ankle get overly stretched or torn. Find out how to avoid ankle sprains and what to do if you get one. Read More Bones, Muscles, and Joints Without bones, muscles, and joints, we couldn't stand, walk, run, or even sit. The musculoskeletal system supports our bodies, protects our organs from injury, and enables movement. Read More X-Ray Exam: Ankle An ankle X-ray can help find the cause of symptoms such as pain, tenderness, and swelling, or deformity of the ankle joint. It can also detect broken bones or a dislocated joint. Read More Bones, Muscles, and Joints Our bones, muscles, and joints form our musculoskeletal system and enable us to do everyday physical activities. Read More Broken Bones Many kids will have a broken bone at some point. Here's what to expect. Read More Broken Bones Bones are tough stuff - but even tough stuff can break. Find out what happens when a bone fractures. Read More Broken Bones What happens when you break a bone? Read More Word! Fracture When a bone breaks, it's called a fracture. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.