Injuries to the hip and femur are common, occurring most often
in the elderly population. There are more than 300,000 hospitalizations
annually in the U.S. for hip fracture; it is estimated that incidence
may double by the year 2040 due to the aging population.1,2 Age,
race, and gender are important factors in hip injuries, with incidence
doubling for each decade past the age of 50 years old. The incidence
is approximately two to three times higher in women than in men.
Morbidity and mortality is substantial, with the majority being
due to prolonged immobilization, deep venous thrombosis, and pulmonary embolus.
It is estimated that 20% of seniors who sustain hip fractures
die within 1 year; the greatest risk is in the first 6 months after
the injury. Nearly another 20% require nursing home care,
costing an estimated $2.8 billion per year.1,3–6 Though
some recent data suggest an overall decline in incidence and mortality
in the U.S., hip and femur injuries remain a major source of morbidity
and mortality world-wide.6 Advanced age and comorbidities
are important risk factors for increased mortality.7,8
The hip is a ball-and-socket joint formed by the femoral head
and the acetabulum. The fibrous capsule that surrounds the joint
on all sides is exceedingly strong. It attaches around the acetabulum
proximally and runs to the intertrochanteric line distally on the
anterior surface. Posteriorly, it falls short of the intertrochanteric
crest and inserts on the neck of the femur. It is weakest posteriorly.
The femoral head is joined to the shaft by the obliquely angled
femoral neck, with the intersection at the intertrochanteric line
formed by the greater and lesser trochanters. Blood is supplied
to the femoral head mainly from the medial and lateral femoral circumflex
arteries that form an extracapsular ring and course inside the capsule
at its insertion to the proximal femur. Less important blood supply
includes branches of the obturator and gluteal arteries, with a
small contribution from the foveal artery at the ligamentum teres.
Hip fractures are classified as femoral head and neck (intracapsular),
trochanteric, intertrochanteric, and subtrochanteric (extracapsular) (Figures 270-1 and 270-2 and Table 270-1). The prognosis for successful
union and restoration of normal function varies considerably with
the fracture type. The vast majority of fractures occur in older
patients with osteoporosis or other bony pathology secondary to
systemic disease. Younger patients are more likely to have femoral
shaft fractures or hip dislocation secondary to high-energy trauma.
Fracture of proximal femur. Fractures of the proximal femur
are traditionally classified as intracapsular and extracapsular.
(Reproduced with permission from Greenspan A: Orthopedic
Radiology. Philadelphia, JB Lippincott, 1988, p. 517.)
270-1 Proximal Femur Fractures: ...