Talar fracture

Original Editor - Merlin Roggeman Top Contributors - Samuel Adedigba and Merlin Roggeman

Description

A talar fracture is a break in the continuity of one of the bones that forms the ankle; the talus.This type of fracture often occurs during a high-energy event, such as a car collision or a high-velocity fall. Because the talus is important for ankle movement, a fracture often results in significant loss of motion and function. In addition, a talus fracture that does not heal properly can lead to serious complications, including chronic pain.[1]

Clinically Relevant Anatomy

The talus is the bone that makes up the lower part of the ankle joint (the tibia and fibula bones of the lower leg make up the upper part of the ankle joint). The talus sits above the heel bone (calcaneus). Together, the talus and calcaneus form the subtalar joint, which is important for walking, especially on uneven ground.[1]

The talus is the second largest tarsal bone. It is uniquely shaped and consists of a body, head, and neck. Approximately two-thirds of its surface is covered with articular cartilage.[2] The superior aspect of the body is widest anteriorly and therefore fits more securely within the ankle mortise when it is in dorsiflexion.

The talus has no muscle or tendinous attachments and is supported solely by the joint capsules, ligaments, and synovial tissues. Ligaments that provide stability and allow motion bind the talus to the tibia, fibula, calcaneus, and navicular.[3]

Mechanism of Injury

Most talus fractures are the result of high-energy trauma such as a car collision or a fall from height. Injuries from sports, particularly from snowboarding, are another, less common, cause of talar injuries.[1]

Fractures occur in all parts of the talus bone. Most commonly, the talus breaks in its mid-portion, called the "neck." The neck is between the "body" of the talus, located under the tibia, and the "head," located further down the foot. Another common site for talus fractures is along the outside of the bone where it juts out slightly. This area of the bone is called the "lateral process." Fractures of the lateral process often occur when the ankle is forced out to the side and are commonly seen in snowboarders.

Clinical Presentation[1][3]

Patients with talus fractures usually experience:

  • Acute pain
  • Inability to walk or bear weight on the foot
  • Considerable swelling, bruising, and tenderness of the hindfoot and midfoot
  • Gross deformity may be present, depending on the displacement of the fracture and any associated subtalar and ankle joint subluxation or dislocation

Diagnostic Procedures

Clinical examination of patients with talar injuries typically reveals swelling and hematoma about the ankle as well as limited range of motion at the tibiotalar, subtalar, and midtarsal joints. Patients are often unable to bear weight on the injured extremity.

Standard radiographic views include anteroposterior (AP), mortise, and lateral views of the ankle and AP, oblique, and lateral views of the foot. The purpose of the mortise view is to align the medial and lateral malleoli parallel to the tabletop, to better visualize the lateral aspect of the talus by preventing an obstructed view by overlap of the fibula. This optimized view can be obtained by positioning the ankle with 15°–20° of internal rotation.

CT, including coronal and sagittal reformatted images, is commonly performed for surgical planning if a talar fracture is seen or strongly suspected at plain radiography

Outcome Measures

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Management / Interventions

Immediate first aid treatment for a talus fracture, as with any painful ankle injury, is to apply a well-padded splint around the back of the foot and leg from the toe to the upper calf to immobilize the limb and protect it. Elevating the foot above the level of the heart helps to minimize swelling and pain. Specific treatment depends upon the severity and the type of fracture, so it is important to seek immediate medical attention.

Nonsurgical Treatment

Only fractures that are well-aligned (stable) can be treated without surgery. This is very rare in a talus fracture, however, because of the high-energy force that causes the injury.

Casting. A cast will hold the bones in the foot in place while they heal. You will have to wear a cast for 6 to 8 weeks. During this time, you will be asked to limit the amount of pressure you put on your foot. The goal is for the bone to heal enough for you to bear weight on it without the risk that it will move out of position.

Rehabilitation. When the cast is removed, your doctor will give you exercises to help restore the range of motion and strengthen your foot and ankle.

Surgical Treatment

If the bones have shifted out of place (displaced), surgery to internally set and stabilize the broken pieces results in the best outcome and reduces the risk of future complications.

Open reduction and internal fixation. During this operation, the bone fragments are first repositioned (reduced) into their normal alignment. They are then held together with special screws or metal plates and screws

Differential Diagnosis

  • Ankle sprains

Complications

Resources

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References

  1. 1.0 1.1 1.2 1.3 Orthoinfo.aaos.org. (2019). Talus Fractures - OrthoInfo - AAOS. [online] Available at: https://orthoinfo.aaos.org/en/diseases--conditions/talus-fractures [Accessed 31 Jan. 2019].
  2. Melenevsky Y, Mackey RA, Abrahams RB, Thomson III NB. Talar fractures and dislocations: a radiologist’s guide to timely diagnosis and classification. Radiographics. 2015 May 13;35(3):765-79.
  3. 3.0 3.1 Fortin PT, Balazsy JE. Talus fractures: evaluation and treatment. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2001 Mar 1;9(2):114-27.