Foot fracture

Any bone in the foot may break, but only talus, calcaneus, and 5th metatarsal fractures were included in the lecture. However, I was asked regarding toe fractures on the exam so I’ve included those as well.

The talus is a so-called free-floating bone in the foot and ankle joint, referring to how it doesn’t have any tendons or muscles attaching to it. Its blood supply is vulnerable to injury. Fractures of the talus may involve the talar neck, body, the posterior, medial, or lateral processes, or be transchondral (Flake fracture). Talar neck fractures are at highest risk of causing avascular necrosis. Talar fractures occur due to fall or high energy trauma. These fractures are classified according to Hawkin. Treatment is surgical and urgent (< 6 hours).

The calcaneus forms the heel of the foot. Fractures of the calcaneus are uncommon but are usually severe and have high risk of complications, especially intraarticular ones. Often occuring due to falls, they’re often bilateral. A plantar ecchymosis may be present. Treatment may be conservative or surgical. It’s sometimes called the “lover’s fracture” or “Don Juan fracture”.

The fifth metatarsal is one of the most common sites of fracture of the foot. They’re predisposed to poor healing due to poor blood supply. Fractures can occur in three different areas. A Jones fracture is a proximal fracture of the second zone of the metatarsal base. They’re treated conservatively, except intraarticular and Jones fractures.

Etiology

Talus fracture can occur due to plantarflexing or dorsiflexing forces, as well as axial forces, usually due to falls from significant height or high energy trauma.

Calcaneus fracture also typically occurs from axial force, usually fall from significant height.

Fifth metatarsal fracture occur due to direct trauma, stress, inversion, or crush.

Fractures of the toes may occur due to direct trauma.

Classification

Talus fractures are classified according to the Hawkin classification.

Fracture	Description
Type I	Nondisplaced vertical fractures of the neck
Type II	Displaced fractures + subluxation or dislocation of the subtalar joint
Type III	Fractures with dislocation of both the subtalar and ankle joints

The risk for avascular necrosis increases for each type, ranging from 10% in type I fractures to 90% of Type III fractures.

Calcaneus fractures are classified as extraarticular (1/4 of cases) or intraarticular.

Fifth metatarsal fractures come in three types:

Tuberosity avulsion fracture
Jones fracture (proximal fracture within 1,5 cm of the tuberosity, the second zone)
Midshaft fracture

Clinical features

Typical features of talus and calcaneus fracture are classic signs of fracture, including pain, swelling, and inability to bear weight. In case of talus fracture, the patient may be tender at or below the ankle. Calcaneal fractures may cause a plantar ecchymosis, and the heel may appear to be widened due to the deformity. Fractures of the fifth metatarsal may cause pain along the lateral margin of the foot.

Calcaneus fractures are usually severe, causing severe swelling and pain. Possible early complications include compartment syndrome and skin necrosis. Due to the mechanism (fall from height) calcaneus fractures are often bilateral.

Diagnosis and evaluation

X-ray should often be followed up by CT for talus or calcaneus fractures. X-ray alone is usually sufficient for 5th metatarsal fractures and toe fractures.

Treatment

Talus fractures are treated surgically to prevent avascular necrosis, preferably within 6 hours. Dislocated fractures should be reduced immediately. Surgical treatment involves screw fixation followed by casting.

Calcaneus fractures may be treated conservatively or surgically, depending on their severity and whether they’re intra or extraarticular. Surgical treatment may involve ORIF (with plate fixation) or the Zadravecz technique.

Fifth metatarsal avulsion fractures are treated conservatively (unless intraarticular). Jones fractures are treated with screw fixation or non-weightbearing cast. 5th metatarsal shaft fractures are treated conservatively with cast fixation.

Toe fractures are treated conservatively, with the exception of dislocated fractures of the first toe, which are treated surgically.