One of the most frequent regions in the human body to sustain trauma is the foot. Ten percent of all fractures are located in the feet. This is because of their flexibility and the absence of structural protection provided by large muscles and soft tissues.
When diagnosing a patient with foot trauma, we must take into consideration direct and indirect trauma, fatigue and insufficiency fractures, as well as pathological fractures secondary to accompanying diseases such as diabetes or metastatic disease.
The radiologist must be familiar with injury morphology and ligamentous patterns of injury as well. Prompt recognition of the specific patterns of foot dislocation and fracture allows early and accurate treatment with increased likelihood of good outcome.
Educational Goals / Teaching Points
Review the foot anatomy; To understand the biomechanics of foot fractures; Discuss the anatomical considerations in foot fractures; To discuss the radiological diagnostic methods which can be used when foot fractures are suspected
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The foot is a complex structure to evaluate using conventional radiography. The foot is made up of 26 bones, 33 joints, 107 ligaments, and 19 muscles which make error-free reports difficult. The bones of the foot are divided into three categories: tarsal, metatarsal, and phalanges.
The tarsal bones of the foot are organised into three rows: proximal: the talus and the calcaneus, (hindfoot) intermediate: the navicular, and distal: the cuboid and the three cuneiform (midfoot). The forefoot contains the metatarsals and the phalanges.
Fractures that may occur in the hind and midfoot include that of the calcaneus, talus, navicular, cuneiforms, cuboid. Injuries, both fractures and dislocations, may be seen in the Lisfranc and Chopart joints, and finally, fractures and dislocations of the metatarsals and phalanges may occur. Moreover, the presence of sesamoid bones and anatomical variants may compound the problem of recognising fractures.
Delays in fracture diagnosis are not rare; found to be up to 6.5 to 7.8% of patients in one study. This occurs because of their subtlety and a lack of typical signs and symptoms apart from swelling and pain.
X-ray examination is the most common type of examination in foot injuries. Many authors conclude that x-rays are accurate in detecting foot fractures and dislocations. MDCT is more sensitive and more specific than radiography but not as cost effective and exposes the patient to higher levels of radiation. MRI is better for stress injury diagnosis; however, it is not as easily accessible in all locations.
Failure to recognise these injuries can lead to complications causing difficulty with ambulation as well as persistent and possibly long-term pain.
An understanding of foot anatomy and the biomechanics of injury allows the radiologist to more easily recognize fractures and dislocations of feet.