Ankle

The ankle is the connecting hinge between the lower leg and the foot. One distinguishes the ankle ( OSG ) and the lower ankle (USG ). Both ankles together are functionally an articulation cylindrica.

Ankle joint ( OSG )

In the upper ankle joint (Latin articulatio talocruralis, also ankle joint), the lower (distal) ends of the tibia (tibia) and the fibula ( fibula ) and the anklebone ( talus ) the articulating bones. In detail, these are defined by the inside of the ankle ( medial malleolus ) of the tibia and the lateral malleolus ( lateral malleolus ) of the fibula ankle mortise formed (also ankle joint ) and the talus role ( talar dome ).

The ankle mortise is held together by the distal tibiofibular syndesmosis. Syndesmosenverletzungen found in about 16% of all ankle injuries and are typically also at Weber -C and partially at Weber B fractures of the lateral malleolus. There are four bands:

• The interosseous tibiofibular ligament, the distal portion of the interosseous membrane and can be defined as a stand-alone tape it. The grain direction is obliquely downward. From the tibia to the fibula in lateral- distal- anterior direction The band is about 2-3 cm wide and ends about 1 cm above the joint line. The belt carries about 22 % of the stability of the Syndesmosenapparates.
• The anterior tibiofibular ligament (anterior Syndesmosenband ) extends in an oblique direction from the clearly demarcated anterior tubercle ( Tubercle de Charcot ) on the lateral distal tibia to the anterior tubercle of the fibula. It contributes to about 35% to Syndesmosenstabilität.
• The posterior tibiofibular ligament (rear Syndesmosenband ) connects the trailing edge of the lateral malleolus to the posterior tubercle on the lateral posterior tibia and has a much more horizontal course than the front Syndesmosenband. It has a share of about 9 % at the Syndesmosenstabilität.
• The transverse tibiofibular ligament was partially described as a separate band, partly as a deeper and more distal portion of the rear Syndesmosenbandes and also has a horizontal orientation. After the front Syndesmosis it contributes about 33% significantly contributes to the stabilization of the Syndesmosis.

The mechanics of the ankle joint is not quite a hinge joint because its axis is inclined by the ankle bone and the ankle joint role. This allows - simplified terms - the reduction ( plantar flexion ) and the lifting of the foot ( dorsiflexion and dorsiflexion ). In addition, a low level of internal and external rotation as well as a one- ( pronation ) and minimal external rotation ( supination ) of the talus role is possible. After the neutral zero method of motion ( plantar - dorsal) to comprise a range of 50 ° -0 ° -30 °. However, the anchor leg is not completely roll reaches the shape of a cylinder, as it is wide in the front region than in the back. The slight movements to the side ( abduction and adduction), which are larger in the lowered distance, thus in the raised base almost impossible. The ankle is one of the most heavily loaded joints of the body, as it has to bear the whole body weight with each step and transfer it to the ground.

Due to this high load and not completely cylindrical anatomy and the different training of band connections is a diversity breach of opportunities that relate primarily to the bands, but also the bones found. Injuries of the ankle are very common. Especially the " sprains " and the " twisting " of the joint often occur.

In the ankle develop without previous injury compared to other joints rarely wear ( arthrosis ). Most arthritis of the ankle are thus secondary ( post-traumatic ) arthritis, ie long-term consequences of severe or inadequately treated injuries such as ankle sprain fractures or complex capsular ligament injuries. To replace developments and techniques that are mature at the knee joint in order to improve the cartilage surface ( transplantation of chondrocytes or cartilage - bone cylinders ) or by an endoprosthesis ( artificial joint ), now also succeed at the ankle. The treatment options are still limited, mainly because the joint is shaped irregularly and very tight, making it a diverse arthroscopic treatment is not so easily accessible, such as the knee joint. Basically a stepped regimen is applied and started with the conservative treatment (including shoe measures), which in some cases leads to years of relief of symptoms in many cases. If in osteoarthritis development of these possibilities have been exhausted, there are essentially two surgical treatment options: The stiffening of the ankle joint ( arthrodesis of the ankle joint ) or the installation of an artificial joint (ankle endoprosthesis ).

On the lower ankle (USG )

The lower ankle (Latin articulatio talotarsalis ) is part of the foot and is in turn in the front lower ( articulatio talocalcaneonavicularis ) and the rear lower ankle joint ( articulatio subtalaris, articulation talocalcanearis ) divided. The two chambers are separated by the talus - calcaneal ligament ( interosseous talocalcaneal ), this band is in the tarsal canal. The function of this volume is mainly the management of blood vessels to feed the talus.

The rear chamber of the lower ankle joint ( articulatio subtalaris ) is of the anklebone ( talus ) and the heel bone ( calcaneus ) is formed. Here are the posterior articular surface of the calcaneus (facies posterior articular talaris ) and the posterior articular surface of the talus (facies posterior articular calcanea ) in conjunction. The anterior chamber of the lower ankle joint ( articulatio talocalcaneonavicularis ) is of talus, calcaneus and scaphoid ( navicular ) is formed. Here articulate front and middle articular surface of the heel and ankle bone together. Another articulation between the calcaneus and navicular, here are the corresponding articular surfaces of the calcaneus (facies articular calcanea ) and the scaphoid ( navicular articular facies ) in an articulated connection. Heel and navicular bone together form a well in which the talus has only one axis of motion.

The axis of movement of the lower ankle joint extending from the center of the navicular to the outside of the calcaneus. The angle to the horizontal plane is approximately 30 °, while the angle to the sagittal plane of about 20 °. In the lower ankle joint so only two movements are possible: 10 ° eversion (lift the outer side of the foot ) and 20 ° inversion (lifting of the inside of the foot ) from the neutral zero position.

Ligaments of the ankle

The ankle joint is held together by a series of bands. The delta band ( deltoid ligament or collateral ligament medial ) consists of a rail -navicular - part ( pars tibionavicularis ), a shin - calcaneal part ( pars tibiocalcanea ) and a front and rear shin - talus - part ( pars tibiotalaris anterior and posterior). The outer band ( lateral collateral ligament ) is from the anterior and posterior talus - fibula ligament ( anterior talofibular ligament and posterior talofibular ) and a calcaneus - fibula ligament ( calcaneofibular ) formed. The ankle joint is controlled by the anterior and posterior tibial - fibula ligament ( anterior tibiofibular ligament and posterior tibiofibular ) held together.

The outer bands are particularly vulnerable to Umknickverletzungen; one speaks in this case of a Außenbandruptur. Umknickverletzungen often lead to damage to the capsular ligaments (bands strain, elongation, tearing ). Bony injuries occur rather rarely ( rupture of the outer and inner ankle, rupture of the connecting band between the tibia and fibula ). The hocks are very often affected with about 20 % of all sports injuries.