ankle fracture

Ankle fracture: description

An ankle fracture (or ankle fracture) is usually a fracture of the upper ankle (OSG), that is, the inner and / or outer ankle on the foot is broken – usually it is the outer ankle. Almost always the surrounding band structures are injured. The ankle fracture is one of the five most common human fractures.

The abutment (tibia), fibula (fibula), talus (talus) and the surrounding ligaments are involved in the construction of the upper ankle joint. The tibia, fibula and ankle bone together form the so-called ankle fork. The tibia and fibula are connected to a connective tissue membrane (membrana interossea) and are surrounded at the bottom by a front and rear band structure (syndesmosis).

The upper ankle is responsible for lifting and lowering the foot. The external malleolus is the articular process of the fibula and the internal malleolus of the tibia. The surrounding ligaments ensure the stability of the ankle.

Ankle fracture: symptoms

Typical symptoms of an ankle fracture are pain. Due to the fracture, the affected area is swollen and shows a bruise around the inner and outer ankle. If the ligaments are also affected, the joint is unstable. The mobility of the foot is limited, walking hardly possible. The foot can not be charged any more. Other symptoms may include malalignment and abnormal feelings in the foot.

In severe cases there is an open ankle fracture. Bone parts protrude through the skin to the outside. Such an open wound always means a greater risk of infection, and this can delay healing.

Ankle fracture: causes and risk factors

The ankle fracture is often a sports injury, but older people are affected. For example, if you walk on uneven ground, suddenly change direction, or fold over and jump up, you can quickly break your ankle. Even a fall from a small height can cause such a fracture. As a rule, the ankle fracture is a Umknicktrauma (supination trauma).

The ankle fracture is divided into Weber. The height of the fracture plays a role in relation to the lower band structure of the tibia and fibula. The Weber fracture distinguishes three forms:

• Weber A fracture: fracture of the fibular bone below the band structure (syndesmosis). The ankle fracture is at or below the joint space.
• Weber B fracture: fracture of the fibular bone and / or tibial bone at the level of the band structure. The band structure may possibly be mitverletzt.
• Weber C fracture: fracture of the fibular bone above the ligamentous structure. The band structure is always involved.

The undeflected Weber B fracture is the most common type of fracture. In addition, in all three forms, the inner malleolus or the inner band may be injured, although this is not a requirement for the classification. If both internal and external ankle are affected, it is called a bimalleolar ankle fracture (ankle = Malleolus).

In addition, physicians use other terms for an ankle fracture: A Maisonneuve fracture is a high fracture of the fibula bone, the connective tissue membrane between caliber and tibia bones is torn. One speaks of a so-called Volkmann fracture, when not only the inner and outer ankle is broken, but also the rear lower edge of the tibial bone has ripped out.

Ankle fracture: examinations and diagnosis

If you suspect an ankle fracture, you should consult a doctor for orthopedics and traumatology. To see if your ankle is broken, the doctor will first ask you about the accident and your medical history. Possible questions are:

• How did the accident happen?
• Do you have pain?
• Do the pain occur during exercise?
• Did you have any complaints such as pain or restricted movement in the foot area before?

Subsequently, the doctor will examine you. He examines where the fracture is located and whether vessels and nerves have been injured. In addition, the doctor checks whether soft tissue is injured and how stable the upper ankle joint is. This is important to plan for later treatment. The doctor will also check whether the knee joint, the lower leg or the foot itself was injured.

Apparative diagnostics

To confirm an ankle fracture, the foot is X-rayed in two planes. It will take a shot from the front with 15 degrees of internal rotation and one from the side. In the case of a debris fracture, additional computed tomography (CT) examinations are performed. If there is a suspicion of a high calf bone fracture, shots of the entire fibula are taken in two planes. An additional magnetic resonance imaging (MRI) can clarify questionable ligament, soft tissue and cartilage injuries.

Ankle fracture: treatment

If the ankle is actually broken, the treatment depends on the type of fracture: open or closed, displaced or not shifted, Weber classification. The aim of the treatment is to correctly anatomically align the bone fragments and the articular surfaces again and to reconstruct the band structures.

If there is a strong shift and dislocation of the upper ankle joint, the fracture should already be emergency closed at the accident site by a doctor and immobilized in a suitable splint. This should be done regardless of the subsequent treatment, as otherwise soft tissue damage could occur.

Ankle fracture: Conservative treatment

For stable and non-displaced ankle fracture can be treated conservatively. This is usually a Weber-A fracture and Weber-B fracture. The foot is usually kept quiet until the swelling has subsided. For this purpose, a split lower leg gypsum is first applied, which is then replaced by a circular plaster, a plastic splint or a special orthosis (such as Vacoped). Overall, the foot should be kept quiet for about six weeks and be partially loaded with only about 15 kilograms. It is important to have sufficient thrombosis prevention, since the foot is not moved over the entire period, which promotes the formation of blood clots (thrombosis).

Even slight irregularities in the upper ankle can lead to post-traumatic arthritis. Therefore, it is important that the foot is accurately and anatomically aligned in an ankle fracture, if necessary in one operation. The procedure is best done within the first six to eight hours, if no strong swelling has developed yet. If the soft tissue is swollen, the foot should be stabilized in a fully split and well padded lower leg gypsum and – after the swelling has gone back – be stored high.

Ankle fracture: surgical treatment

Leap fractures that can not be sufficiently immobilized in the cast and tend to shift again, as well as fractures with severe soft tissue damage and multiple injuries are first stabilized with a joint-bridging “fixator external” (retention system to stabilize bone fragments). This allows the ankle fracture to be immobilized effectively and painlessly. In addition, the fragments can be aligned beyond the band structures and the soft tissues are more easily treated with decongestant measures (such as cold therapy and pulse compression).

If the capsule and ligaments are affected, they are sutured and cartilage pieces are realigned. The fibula is usually screwed and stabilized with a neutralization plate. A broken inner ankle is screwed directly, smaller fragments are fastened with a Zuggurtung.

Fibula fractures up to the middle of the lower leg are directly stabilized. If there is a so-called Maisonneuve fracture, ie a high fibula fracture, it is important to align the ankle fork exactly in length and rotation again. For this purpose, the fibula is immobilized indirectly with a set screw near the ankle between the fibula and tibia for about six weeks. The band structure (syndesmosis) is fixed again with resorbable sutures.

Ankle fracture: aftertreatment

After the operation of the ankle fracture, the foot is held in place with a lower leg split plaster. In an external fixator this is left in right angle position of the ankle to prevent a Spitzfuß. Once the surrounding soft tissue is abraded, the patient will receive a detachable shoe (Vacoped) or circular plaster for approximately four to six weeks, depending on how stable the foot is after surgery and whether any ligaments have been injured.

Ankle fracture: disease course and prognosis

In 95 percent of patients with a Weber-A fracture treatment shows good results. In patients with a Weber C fracture, it is 75 percent.

After an operation you should not burden the foot for four to six weeks with more than 15 to 20 kilograms. Only after six weeks you can fully load the ankle again. You can only become active again after three to six months.

If an implant was used during the operation, it will be removed after about 10 to 12 months. Adjusting screws can be removed after six weeks.

If a Volkmann fracture is incompletely aligned, premature osteoarthritis can develop because the fibula bone has been anatomically misaligned or the cartilage damage is too great.

In general: The treatment of a ankle fracture shows in 80 percent of all cases a very good result, if it starts very early with a functional and exercise-stable aftercare.