Types of Ankle Fractures

Broken Ankles

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Ankle fractures are serious injuries to the bones surrounding the ankle joint.  However, saying someone has a broken ankle tells us very little about proper treatment, rehab, or prognosis.  In order to get more information, we must first classify the injury by knowing where the bone is broken, and if there are any associated ligament injuries.


Lateral Malleolus Fracture

The most common type of ankle fracture is a break of the end of the fibula bone, also called a lateral malleolus fracture.  Lateral malleolus fractures are often stable injuries, and can be treated similar to a severe ankle sprain injury.  However, when they occur along with injury to the ligaments surrounding the ankle, surgical treatment may be necessary. 


Bimalleolar Fracture

A bimalleolar fracture occurs when the bone is broken on both the inner and the outer side of the ankle joint.  These fractures almost always require surgery because the ankle joint is unstable with no support from either the inner or the outer side.  If the fracture heals in anything less than a perfect position, the ankle joint alignment will be affected and could lead to accelerated arthritis of the ankle.  Even with surgical treatment, ankle cartilage can be damaged at the time of the fracture leading to a higher chance of arthritis, but you should aim to do as much as possible to repair these fractures properly to keep the chance of long-term problems as low as possible.


Bimalleolar Equivalent Fracture

A bimallerolar equivalent is treated very similar to a bimalleolar fracture.  In this case, there is only a break on the bone on one side of the ankle joint, but there is also ligament damage on the other.  Because the ligaments are damaged, the ankle is unstable, as was the case in a bimalleolar fracture, and therefore the treatment remains the same.  In these patients, surgery is almost always recommended to restore stability to the ankle joint in an effort to lower the chance of developing arthritis of the joint.


Medial Malleolus Fracture

A fracture of the inner side of the ankle occurs to the bone on the end of the tibia; that part of the bone is called the medial malleolus.  An isolated medial malleolus fracture is much less common than an isolated lateral malleolus fracture.  When these injuries do occur, surgery is much more commonly used in treatment.


Trimalleolar Fracture

A trimalleolar ankle fracture is essentially the same as a bimalleolar ankle fracture, but the bone in the back of the tibia is also fractured.  The bone in the back of the tibia is called the posterior malleolus.  Sometimes, if a large enough fragment of bone is fractured, the surgery must also address that fragment.  However, most commonly, the surgery is no different than for a bimalleolar ankle fracture.


Maisonneuve Fracture

A Maisonneuve fracture is a less common injury, but needs to be considered as can easily be missed without a thorough examination.  In the Maisonneuve fracture, the bone is injured on the inner side of the ankle (the medial malleolus).  While the lateral malleolus is in tact, there is a fracture much higher up on the fibula bone, typically around the knee.  The force of this injury passes through the large ligament that connects the two leg bones, called the syndesmosis.  Because of the damage to this supporting ligament, the ankle is unstable and surgery is most often necessary.


Ankle Fracture Treatment

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As is described, ankle fracture treatment can very widely depending on the specific pattern of bone and ligament injury.  It is important to examine not only the fractured bones, but also the ligaments as damage to ligaments surrounding the ankle can cause just as serious a problem as a bone injury.

When surgery is needed, the goal is to realign the fracture, and restore stability to the ankle joint.  It is critical to correct the alignment of the joint, as even small imperfections can cause significant long-term problems.


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