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
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
Fractures and
dislocations of the midfoot
This injury, sometimes
named a Lisfranc fractive, is commonly seen following head-on road traffic
accidents where the
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.