Chapter 23

The foot has a wide range of normal motion including flexion, extension, inversion, and eversion. In addition, supination and pronation are part of the normal range of foot motion. The foot contains two arches: a longitudinal arch (midfoot) and a transverse arch (forefoot). Weight is normally distributed equally on the forefoot and the heel. Weight is not equally distributed on the metatarsal heads, as the first bears twice as much weight as the remaining four. The maximum weight applied to the foot occurs during the push-off phase of walking and running.

The foot contains 28 bones and 57 articulations (Figs. 23–1 and 23–2). Conceptually, the foot can be divided into three regions: the hindfoot (talus and calcaneus), the midfoot (navicular, cuneiforms, and cuboid), and the forefoot (metatarsals and phalanges).

###### Figure 23–1.

The foot is divided into a hindfoot, a midfoot, and a forefoot. Chopart's joint separates the hindfoot from the midfoot and Lisfranc's joint separates the midfoot from the forefoot.

###### Figure 23–2.

Medial (A) and lateral (B) views of the foot.

Foot fractures are common and account for 10% of all fractures. They are generally the result of one of three basic mechanisms of injury–direct trauma, indirect trauma, and overuse.

### Imaging

Routine radiographs of the foot include the anteroposterior (AP), oblique, and lateral views (Fig. 23–3). These radiographs can be difficult to interpret because bones overlap in all projections. The AP radiograph is used to best assess the medial two tarsometatarsal joints, while the oblique image provides the best view of the lateral three tarsometatarsal joints.1 This alignment is important and will be altered in patients with Lisfranc fracture–dislocations. The lateral radiograph is best for detecting calcaneus fractures.

###### Figure 23–3.

Normal radiographs of the foot. A. Anteroposterior (AP), B. oblique, and C. lateral images.

The radiologic diagnosis of foot fractures is frequently complicated by the secondary ossification centers and sesamoids (Fig. 23–4). Commonly seen sesamoids include the os trigonum, os tibiale externum, os peroneum, and os vesalianum. Sesamoids can be distinguished from fractures by their smooth sclerotic bony margins.

###### Figure 23–4.

The sesamoids of the foot. These bones are commonly confused for fractures.

### Calcaneus Fractures

The calcaneus ...

### MyAccess Sign In

Username
Password

Want access to your institution's subscription?

Sign in to your MyAccess Account while you are actively authenticated on this website via your institution (you will be able to tell by looking in the top right corner of any page – if you see your institution’s name, you are authenticated). You will then be able to access your institute’s content/subscription for 90 days from any location, after which you must repeat this process for continued access.

Ok

### About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess account, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

## Subscription Options

### AccessEmergency Medicine Full Site: One-Year Subscription

Connect to the full suite of AccessEmergency Medicine content and resources including advanced 8th edition chapters of Tintinalli’s, high-quality procedural videos and images, interactive board review, an integrated drug database, and more.

$595 USD ### Pay Per View: Timed Access to all of AccessEmergency Medicine 24 Hour Subscription$34.95

Buy Now

48 Hour Subscription \$54.95

Buy Now

### Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.