One of the seven tarsal bones is called talus. The talus is one of the seven tarsal bones and is involved in both the upper and lower ankle joint: In the upper ankle joint, the ankle bone roll (trochlea tali) is surrounded by the malleolar fork (consisting of the ends of the tibia and fibula). Thus, only lifting and lowering of the foot by approx.
20-30° is allowed.
- In the upper ankle joint, the ankle bone roll (trochlea tali) is enclosed by the malleolar fork (consisting of the ends of the tibia and fibula). Thus, only lifting and lowering of the foot by approx. 20-30° is allowed.
- In the lower ankle joint, a complex interaction of many tarsal bones (including the anklebone) allows the foot to rotate inwards and outwards by 30-50°.
Diseases of the ankle bone
Talus luxation (displacement of the articular surfaces of the ankle bone): In this case, strong force (e.g. falling from a great height) causes a displacement of the articular surfaces in which the ankle bone is involved. This can happen in both the upper and lower ankle joint. The patient himself notices a swelling and restricted movement.
The shape of the ankle joint also looks different. After an x-ray of the foot has ruled out bony fractures, the joint must be repositioned under a short anaesthetic. It is also recommended to relieve the ankle joint for 4-6 months.
Talus fracture (fracture of the ankle bone): Strong forces that compress the foot or severe dislocations can also cause bony injuries to the talus. If there is a fracture of the ankle bone, the patient notices especially a swelling and hematoma formation above the ankle joint. Depending on the severity of the fracture, this fracture can be treated with or without surgery.
Only if the position of the joint is still correct and no joint surface is directly involved can healing be achieved by immobilization with a plaster cast for 3 months without surgery. If this is not the case, an operation should be performed in which the debris is reattached with screws. Even after this, the ankle joint should not be loaded for another 6 weeks.
Complications that are more frequent in cases of fractures of the ankle bone: Arthrosis in the adjacent joints due to small steps in the joints that could not be completely corrected surgically.
- Arthrosis in the adjacent joints due to small steps in the joints that could not be completely corrected surgically.
- In addition, the blood supply to the ankle bone is relatively poorly developed, so that cell death (necrosis) of this tarsal bone occurs more frequently. In this case, the anklebone must be completely removed.
- Talus luxation (displacement of the articular surfaces of the ankle bone):
- Talus fracture (fracture of the ankle bone):
In some people there is an additional small bone, the so-called Os trigonum, at the rear end of the talus.
This accessory bone is mostly roundish to oval and lies at the rear edge of the ankle bone. This occurs in 3-15% of the population and usually remains undetected. If there is a strong strain, especially in athletes, pain can occur in the area of the Os trigonum, which is called Os trigonum syndrome.
However, this can usually be improved by temporary intake of anti-inflammatory drugs (ibuprofen, cortisone) and physiotherapy. If there is no improvement, the Os trigonum can be surgically removed.
