What is Bimalleolar Ankle Fracture: Causes, Symptoms, Treatment, Recovery Time, Surgery

Ankle fractures are one of the commonest injuries and fractures of the lower leg. Bimalleolar fracture is a type of ankle fracture, in which the inner and outer bony prominences at the lower end of the leg breaks or cracks. In this article, we deal with the causes, symptoms, diagnosis, treatment and recovery time of bimalleolar fracture. Knowing about the condition in detail can help in better management and faster recovery.

Ankle is one of the important joint, which bears weight of the body. Ankle fractures are a common event, which occur due to various causes, ranging from accidents to sport injuries. Depending on the type of injury and the number of parts in which the bone breaks during an ankle fracture, it is classified into important types. Bimalleolar ankle fracture is a type of ankle fracture, in which both the inner and the outer end of the ankle break or develop a crack. Bimalleolar ankle fracture is called Pott’s fracture.

The ankle joint is formed of two lower leg bones, tibia on the inner side and fibula on the outer side. Both the bones end with a bump on inner and outer side, which form a part of the ankle. The lower ends of both the bones, tibia and fibula form a joint called syndesmosis joint. The bump or prominence on the inner side of ankle, which is the lowermost part of tibia is called medial malleolus, while the bump on the outer side is called the lateral malleolus. In bimalleolar ankle fracture, there is fracture of both these parts, meaning it is a combination of both medial malleolus fracture and lateral malleolus fracture.

Weber classification is commonly used to classify malleolus fractures and hence also help to differentiate types of bimalleolus ankle fractures. According to this,

• Type A Weber Fracture occurs when lateral malleolus fracture occurs below the syndesmosis joint
• Type B Weber Fracture occurs when lateral malleolus fracture occurs at the syndesmosis joint
• Type C Weber Fracture occurs when lateral malleolus fracture occurs above the syndesmosis joint

Considering this, the bimalleolar ankle fracture is also classified based on the level at which the break is present. Generally, type B fractures or bimalleolar ankle fracture that occur at syndesmosis joint level can cause more instability of the joint and must be treated carefully. From management and surgical treatment point of view, it is important to understand the possible variants of bimalleolar ankle fracture.

The causes of bimalleolar ankle fracture mainly include, twisting the ankle joint, falls, accidents or injuries to the leg, including sports injuries. Sports that involve sudden twisting and turning, which can easily injure the ankle are one of the commonest causes of bimalleolar ankle fracture. Rolling that results from irregular or improper placing of the foot or landing on an uneven surface, too can be one of the causes of bimalleolar ankle fracture. Falls, tripping over too can cause bimalleolar ankle fractures.

Some of the causes of bimalleolar ankle fracture can also be a direct blow to the ankle or sudden, forceful impact on the ankle, as during vehicular accidents. Sometimes, repeated injuries to the soft tissues, ligament tear or weakening of the supporting structures in elderly people or those with joint problems, too can result in bimalleolar ankle fracture.

Symptoms of bimalleolar ankle fracture include pain at inner and outer side of the ankle. Pain may be worse on turning the ankle inwards or outwards with difficulty in standing or walking. Tenderness is noted in the region and more when pressure is applied.

Following an injury, severe pain and swelling of the area is the commonest symptom of bimalleolar ankle fracture. Bruising or signs of local injury may be noted. In severe fractures, the injured or displaced bones may be noticeable.

Symptoms of bimalleolar ankle fracture caused due to weak ligaments may cause pain along with ligament instability. Another common symptom is the inability to bear weight on the ankle, stand or walk. Pain may worsen and may be present even after low impact activities like walking and eventually even at rest. Some may also experience ankle stiffness and swelling around the injured area. Other symptoms of bimalleolar ankle fracture include limited range of movements, pain on moving or turning the ankle and difficulty in walking.

Diagnosis of bimalleolar ankle fracture can be made based on the history, clinical examination and X-rays. The history often reveals an accident, fall or sports injury as the complaints begin soon following the injury. Examination of the ankle joint reveals pain, tenderness and swelling, which is evaluated to understand if it is a soft tissue injury or a fracture. As the symptoms are similar, it is difficult to differentiate between an ankle sprain and an ankle fracture. More so, the diagnosis of bimalleolar ankle fracture can be typically confirmed by X-rays and other scanning investigations.

However, the Ottawa ankle rule protocol is followed to determine if the injury is a possible fracture or not, based on which an X-ray is ordered. In general, if there is pain and tenderness at the medial and lateral malleolus or if the person is unable to walk due to severe ankle pain and swelling, a fracture is suspected and X-ray is advisable. X-ray confirms a break in the bone, in this case, it is medial and lateral malleolus (inner and outer side of the ankle). It also gives an idea about the type and severity of bimalleolar ankle fracture. If other soft tissue damage, ligament injuries or other fractures are suspected, additional scans like CT scan and MRI may be needed.

The treatment of bimalleolar ankle fracture in case of fresh injury to the ankle joint, needs immediate treatment, which includes the following.

Resting the joint and elevating the leg is often advisable.

Icing can be done for pain and swelling but is best avoided if there is a severe injury or if a complicated fracture is associated with dislocation or displacement.
In case of displacement of bones, the treatment of bimalleolar ankle fracture would require joint reduction, in which the displaced bones are brought to their original position. This often needs emergency medical assistance.

The possibility of nerve injury and other soft tissue injury must be evaluated to plan appropriate investigations and treatment.

Treatment of bimalleolar ankle fracture includes conservative (non-surgical) and surgical approach. Treatment selection depends on the type and severity of the fracture and the condition of the patient. In this, conservative methods of treatment are used, which include medicines, braces, rest and physical therapy, allowing time for the fracture to heal on its own.

Usually, conservative treatment of bimalleolar ankle fracture, is recommended for less severe and uncomplicated injuries. Fractures that are often not out of place and in patients who are not active, can be managed well with conservative or non-surgical treatment. Conservative treatment may also be advised when the fractured pieces of bones are too small to be repaired surgically. However, for treatment of bimalleolar ankle fracture with dislocation surgical treatment is needed.

Conservative treatment of bimalleolar ankle fracture includes the use of removable braces or cast. The healing usually takes up to 6 weeks, during which the fractured ankle is supported by the cast or braces. Depending on the condition, the person may be allowed to bear weight or restricted from bearing weight on the injured leg. Usually, weight bearing on the fractured leg is to be avoided for at least 6 weeks, post which, it depends on the healing of the fracture. Regular monitoring and repeated X-rays are taken to check the healing and to detect any change of position of the fracture.

Treatment of bimalleolar ankle fracture also includes the use of non-steroidal anti-inflammatory drugs (NSAIDs), for pain management. Any additional medicines and supplements may also be considered, if appropriate. For people with nutritional deficiencies, diabetes, circulatory problems and elderly adults, appropriate medications need to be given to ensure proper healing.

Depending on the severity and complications of the injury, the treatment of bimalleolar ankle fracture may include surgical correction. Generally surgical treatment of bimalleolar ankle fracture is recommended when the fracture is out of place, the fracture does not heal or there is non-union or when the ankle is unstable. Sometimes, even if the fracture is not out of place, but if there seems a risk of non-union or if the patients are very active, surgery may be considered. Surgery is often performed to align and stabilize the bones, limit ligament damage and speed up the recovery process. While the type of surgery depends on injury and bone fragments, most surgical corrections are done using screws, plates and wiring options.

Possible complications of surgery of bimalleolar ankle fracture include the risk of infections and delayed healing. Another important risk of bimalleolar ankle fracture is the cartilage damage, which increases the risk of ankle arthritis. People with diabetes, elderly adults and those who smoke may be at greater risk of complications, as the wound healing may be slow in such cases. However, with appropriate timely treatment and effective management, the complications can be minimized and proper healing can be expected.

Rehabilitation plays an important role in the treatment of bimalleolar ankle fracture. Whether the fracture is treated with conservative or surgical treatment, appropriate rehabilitation programs promotes better healing and reduces the risk of long term pain and complications. For surgical treatment of bimalleolar ankle fracture, early postoperative physical therapy is often advised.

Physical therapy treatment of bimalleolar ankle fracture aims to improve the movement of ankle joint and progress through weight bearing and then standing and walking. Exercises help to strengthen the supporting muscles, prevent injuries and promote better healing.

Weight training is progressively done so that the healing of the ankle fracture is assessed and it gains the strength to bear weight, so that partial and then complete weight bearing can be done. This is done over a span of 3 to 4 months, post which most bimalleolar ankle fracture can get healed.

Recovery time in bimalleolar ankle fracture varies from person to person and depends on the type and severity of the injury and the overall health of the person. On average the recovery time is approximately 6 weeks, while a lot depends on the rehabilitation. In cases that need surgery, recovery time is longer, around 3 to 4 months. However, in some cases, the recovery time for bimalleolar ankle fracture may be even longer while it may take time to return to sports. But with timely treatment and effective rehabilitation, good healing and recovery of bimalleolar ankle fracture can be expected.

Also Read:

• Ankle Joint Fracture: Types, Classification, Symptoms, Treatment, Recovery
• Trimalleolar Fracture: Causes, Signs, Symptoms, Treatment-Conservative, Surgical
• Compound Ankle Fracture: Causes, Symptoms, Treatment, Recovery
• Ankle Fracture Surgery-ORIF

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