Fracture.
of the upper femur
Epidemiology
Fractures of the upper end of the femur are both common and serious. In
children a slipped upper femoral epiphysis (a fracture of the epiphyseal plate)
will lead to a lifetime of pain and disability. In adults a fracture of the
upper end of the femur is a very high-velocity injury which is difficult to
treat. In the elderly fractured neck of femur is the ‘bread-and-butter’ of
orthopaedic trauma practice, with over 100 000 cases of fractured neck of femur
each year in Britain alone.
Subcapital
fractured neck of femur
This is a very common fracture in the elderly osteoporotic patient. The
sclerosis produced by osteoarthritis tends to protect the patient from this
fracture so the hip joint itself is usually healthy at the time of the accident.
The problem with this fracture is that the majority of the blood supply to the
femoral head travels up the femoral neck. A subcapital fractured neck of femur (Fig.
23.14) may destroy the blood supply to the femoral head. The older the
patient, and the more displaced the fracture, the less likely the head is to
recover its blood supply.
History
Some patients actually give a history of feeling the femur break and
then falling as a result of this, while others appear to break the femur as a
result of the fall. Either way, they complain of severe pain in the hip and are
usually unable to walk.
Examination
The leg may appear shortened and externally rotated.
Investigation
On an AP X-ray the fracture may be difficult to see, but it will be
shown more clearly on the lateral view as the head may displace posteriorly. On
the AP X-ray the only clue to the presence of a fracture may be a discontinuity
in the trabecular lines running up the femoral neck into the head.
Treatment
The Garden
classification divides these fractures into four grades (see Fig. 23.15 and
Table 23.5):
•
grade 1 is an incomplete fracture of the neck;
•
grade 2 is a complete fracture of the neck without displacement;
•
grade 3 has moderate displacement of less than half the diameter of the
femoral neck;
•
grade 4 is a complete off-ended femoral head as seen in the AP or lateral
X-ray.
In
grade 1 fractures it is generally agreed, whatever the age group, that the
treatment of choice is AO screws or other pins introduced up the femoral neck to
hold the femoral head in position. In grade 4 fractures, whatever the age group,
it is unlikely that the femoral head will survive. In patients under 50 years of
age they should be taken to theatre as quickly as possible to reduce and pin the
head as quickly as possible, and fix with screws (Fig.
23.16). The hope is that
the femoral head will revascularise before it collapses. In patients older than
this, the chance of survival of the femoral
Problems
If the femoral head is retained reduction can be difficult to achieve
and if pins are used they may displace into the acetabulum. Avascular necrosis
is then a risk depending on the age of the patient, the degree of displacement
and the time to reduction. If the head is replaced then dislocation, bleeding
and infection are early complications, as well as damage to the nerves around
the hip when replacing the joint. Late complications are loosening of the
replacement, and sometimes the acetabulum can be eroded away by the implant,
creating a protrusio-type arthritis (Fig 23.18 and
Fig
23.19).
• Common in osteoporosis
• Treatment depends on displacement and age
• Complication — avascular necrosis