The Common Vein Copyright 2011
Definition
Fractures of the talus are usually caused by fall from a height or a motor vehicle accident. and are often characterized by
Talus fractures can be either open or closed injuries. The location of the fracture on the talus varies. The talus can fracture at the lateral process, posterior process, head, body, or neck.
The Hawkins Classification system for talar neck fractures are graded I-IV. Type I fractures are nondisplaced. Type II fractures have an associated subtalar subluxation or dislocation. Type III fractures have an associated subtalar and ankle dislocation. Type IV fractures involve a type III injury with the addition of a talonavicular subluxation or dislocation.
Lateral process fractures occur from dorsiflexion and external rotation injuries such as in snowboarding. These fractures are difficult to visualize on x-ray.
Posterior process fractures involve the posteromedial and posterolateral tubercle. CT is used to evaluate these fractures. Posteromedial injuries are due to avulsion of the posterior talotibial ligament or posterior deltoid ligament. Posterolateral tubercle fractures are due to avulsion of the posterior talofibular ligament.
Talar head fractures are not as common as other injuries to the talus. These injuries are due to plantarflexion and longitudinal compression of the forefoot.
Osteochondral fractures typically occur with ankle sprains and chronic ankle instability. Medial injuries are in the deep and posterior part of the talus. Lateral injuries are from trauma and are more shallow in nature.
It is sometimes complicated by osteonecrosis, osteochondral injury, osteoarthritis, bleeding, infection, nonunion, malunion, loss of ankle and subtalar motion, compartment syndrome, soft tissue injury, interposition of the long flexor tendons, and vascular injury.
The fracture may be complicated in the acute phase by neurovascular injury, or in the subacute or chronic phases by nonunion, malunion, infection, osteonecrosis, and osteoarthritis. Specific complications pertaining to fractures of the talus include osteochondral abnormalities loss of ankle and subtalar motion, compartment syndrome, soft tissue injury, interposition of the long flexor tendons, and vascular injury.
The diagnosis of this injury is usually made by a combination of physical examination and x-ray imaging.
Imaging includes the use of plain x-rays, and if indicated CT-scan, or MRI.
Talar neck fractures can be treated with closed reduction, casting and non-weightbearing if type I. All subluxation or dislocation injuries require urgent surgical treatment to decrease the risk of soft tissue injury.
Lateral process fractures are typically treated non-operatively with a cast and non-weight bearing if nondisplaced. Displaced fractures greater than 2mm require ORIF. Severely comminuted fractures are treated non-operatively, but may require excision.
Posterior process fractures are treated either surgically or non-surgically depending upon the size of the fragments. Large displaced fragments require surgical excision.
Talar head fractures are treated either non-surgically with immobilization and non-weightbearing. If there are displaced fracture fragments, the treatment is surgical.
Osteochondral fractures can be treated with nonsurgical treatment and casting initially. Displaced fractures may require ORIF or arthroscopic debridement. Osteochondral allografts and microfracture surgery can be used as well.
Normal Ankle in Cross Section |
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The axial section CT scan of the forefoot exemplifies the normal anatomy of the distal tibia, fibula, tibio-talar joint. The talus is central to the stability of the joint Courtesy Ashley Davidoff MD 72583c01 |
The Talus from Above |
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The 3D reconstructed CT scan of the forefoot exemplifies the normal anatomy of the distal tibia, fibula, tibio-talar joint, talo navicular joint, and navicular cuboid. The cuneiforms are also well visualized. This patient does have an avulsion fracture off the navicular but it is not obvious on this view. Courtesy Ashley Davidoff MD 72585 |
References
Davis MF, Davis PF, Ross DS. Expert Guide to Sports Medicine. ACP Series, 2005.
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Wheeless’s Textbook of Orthopaedics: Injuries to the Talus (http://www.wheelessonline.com/ortho/injuries_of_the_talus)