What is the Talus?

The talus is a bone in the foot which plays an important role in the articulation of the ankle joint. This bone transfers the weight of the body to the foot, provides stabilization which allows people to walk, and articulates with a number of bones to create a wide range of movement for the ankle joint. The talus is part of a larger cluster of bones in the foot known as the tarsus; the tarsus bones comprise the ankle and the back of the foot, connecting to the bones which eventually lead to the toes.

This bone has a shape which is somewhat reminiscent of a turtle. It connects to the tibia and fibula in the legs, and the navicular and calcaneus bones in the feet. The structure of the talus allows it to have a somewhat curious blood supply, in which the arterial blood enters from the bottom of the bone, rather than the top, as is more conventional with other bones in the skeleton. The talus is also covered in what is known as articular cartilage, a type of cartilage which creates a smooth surface for articulation so that the bone can move freely within the joint.

Fractures of the talus are sometimes associated with car accidents and falls, and orthopedic surgeons have also noted that they are especially common in snowboarding injuries, because snowboarding boots do not offer complete ankle support. A talus injury can be extremely problematic, requiring the patient to spend up to three months off the foot to avoid injuring the bone while it heals, and the talus is prone to developing avascular necrosis, in which the blood supply to the bone is interrupted, causing the bone to die.

In a simple talus fracture, a surgeon may be able to treat the patient by putting the foot in a cast, and leaving the cast on for at least six weeks. If the bone appears to be healing well and the blood supply is healthy, the cast can be removed, although the patient will need to avoid placing weight on the foot for another six weeks. More serious fractures require surgery to reposition and pin the bone, and the risk of necrosis is increased in such fractures.

If the bone does start to die, surgeons have several options, including drilling through the bone to promote the formation of a new blood supply, fusing the ankle, or replacing the ankle joint with an artificial joint. Healing a talus fracture properly is critically important, because damage to the bone can limit freedom of movement in the foot, causing discomfort and making someone more prone to falls. There is also a risk of developing arthritis, which can be quite debilitating for the patient.