Talar fracture

Original Editor - Merlin Roggeman Top Contributors - Samuel Adedigba, Admin, Merlin Roggeman, Lucinda hampton and Puja Gaikwad

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.

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.

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. 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.

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.

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

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

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Differential Diagnosis

• Ankle sprains
• 
  

Complications

• Avascular Necrosis
• Posttraumatic Arthritis
• Osteonecrosis
• Malunion

Resources

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