Injuries to the foot

The foot is very susceptible to crush injuries. Even if there are no fractures, the damage to the soft tissues causes swelling and stiffness, and is very slow to heal. Prevention is always better than cure, and in Britain all workers are obliged to wear steel-tipped toe-capped boots if there is a possibility of a heavy object landing on or running over their feet. Degloving injuries occur where there is a shearing force on the foot, such as occurs when a wheel of a vehicle runs over the foot. The injury may appear trivial with no fractures on X-ray and merely a blotchy area of skin over the dorsum of the foot. If this skin is insensate, then it is almost certainly been stripped from its underlying blood and nerve supply. Over the next few days the area will demarcate and necrose. In some cases the degloving is complete at the time of the accident (see Fig. 23.49), and it is clear that amputation is the only option. Minor degloving injuries require excision of all dead tissue and immediate grafting if the foot is salvageable.

Frostbite

The toes are particularly susceptible to frostbite, which may be quite painless initially and may not be noticed by the patient. Once again, prevention is far better than cure, and experienced climbers go to great lengths to make sure that frostbite is not setting in. Once it has occurred demarcation occurs over a period of days and, provided that the tissues do not become infected, simple excision of the necrotic areas can be performed when the boundary between dead and living tissue is clear (Fig. 23.50).

Fractures of the hind foot

The talus

Most of the surface of the talus is intra-articular, and so any fracture needs to be perfectly reduced if osteoarthritis is to be avoided. An extra complication is that the blood supply to the proximal half of the talus travels up the neck of this bone. A fracture across the neck leads to avascular necrosis in the same way as a fracture across the waist of the scaphoid bone. These fractures need early reduction and careful monitoring for the onset of avascular necrosis.

The calcaneum

Patients landing on their heels from a great height are likely to suffer a series of fractures passing through the body, including fractures of one or both heel bones. The bone tends to split and to crush. If the fracture is not reduced then the hind foot is greatly widened when it heals, making shoe fit difficult. The fracture lines commonly extend into the subtalar joint, and lead to pain and stiffness in the subtalar joint (Fig. 23.51). This makes walking difficult, especially on rough ground such as building sites. Open reduction and internal fixation of these fractures are extremely difficult because the anatomy of the fracture is difficult to see on ray and there is commonly massive bone loss in the body of the calcaneum (Fig. 23.52). Wounds in the hind foot are slow to heal and swelling may make closure of the wound difficult anyway. The technique should only be attempted in units with considerable experience and with special equipment for reduction and holding of fractures.

Fractures and dislocations of the midfoot

This injury, sometimes named a Lisfranc fractive, is commonly seen following head-on road traffic accidents where the feet are jammed between the pedals of the car. These injuries are a blend of fractures and dislocations combined with massive soft-tissue swelling. If they are not reduced the arch of the foot is lost and the foot becomes stiff and painful. Reduction is best performed under an image intensifier and Kirschner wires are used to transfix the midfoot to hold fractures and dislocations reduced (Fig. 23.53).

Fractures and dislocations of the toes

These injuries are common, and if they are stable when reduced can be treated symptomatically or with a buddy strapping (tapping the injured toe to the adjacent toe). If the fracture or dislocation is unstable then the toe can be held by transfixing it with a wire driven through from the distal phalanx into the metatarsal head.