A hip fracture is a femoral fracture that occurs in the proximal end of the
femur, near the hip. The term "hip fracture" is commonly used
to refer to four different fracture patterns and is often due to
osteoporosis; in the vast majority of cases, a hip fracture is a fragility
fracture due to a fall or minor trauma in someone with weakened osteoporotic
bone. Most hip fractures in people with normal bone are the result of
high-energy trauma such as car accidents, falling from heights, or
sports injuries. In the UK, the mortality following a
fractured neck of femur is between 20% and 35% within one year in people aged
82, ± 7 years, of whom 80% were women. Signs and symptoms
The classic clinical presentation of a hip fracture is an elderly patient who
sustained a low-energy fall and now has pain and is unable to bear weight. On
examination, the affected extremity is often shortened and unnaturally,
externally rotated compared to the unaffected leg.
Risk factors Hip fracture following a fall is likely
to be a pathological fracture. The most common causes of weakness in bone are:
Osteoporosis. Homocysteine, a toxic 'natural' amino
acid linked to the cause of heart disease.
Other metabolic bone diseases such as Paget's disease, osteomalacia,
osteopetrosis and osteogenesis imperfecta. Stress fractures may occur
in the hip region with metabolic bone disease.
Benign or malignant primary bone tumours are rare causes of hip fractures.
Metastatic cancer deposits in the proximal femur may weaken the bone and
cause a pathological hip fracture. Infection in the bone is a rare cause of
hip fracture. Smoking.
Mechanism = Functional Anatomy=
The hip joint, an enarthrodial joint, can be described as a ball and socket
joint. The femur connects at the acetabulum of the pelvis and projects
laterally before angling medially and inferiorly to form the knee. Although
this joint has three degrees of freedom, it is still stable due to the
interaction of ligaments and cartilage. The labrum lines the circumference of
the acetabulum to provide stability and shock absorption. Articular cartilage
covers the concave area of acetabulum, providing more stability and shock
absorption. Surrounding the entire joint itself is a capsule secured by the
tendon of the psoas muscle and three ligaments. The iliofemoral, or Y,
ligament is located anteriorly and serves to prevent hip hyperextension.
The pubofemoral ligament is located anteriorly just underneath the
iliofemoral ligament and serves primarily to resist abduction,
extension, and some external rotation. Finally the ischiofemoral ligament on
the posterior side of the capsule resists extension, adduction, and
internal rotation. When considering the biomechanics of hip fractures, it is
important to examine the mechanical loads the hip experiences during low
energy falls. = Biomechanics=
The hip joint is unique in that it experiences combined mechanical loads.
An axial load along the shaft of the femur results in compressive stress.
Bending load at the neck of the femur causes tensile stress along the upper
part of the neck and compressive stress along the lower part of the neck. While
osteoarthritis and osteoporosis are associated with bone fracture as we age,
these diseases are not the cause of the fracture alone. In a study conducted in
Umea, Sweden, Bergsten et al. discovered that low energy falls from heights of
one meter or less were the leading cause of hip fracture in the elderly adult
population . Taking into account that falls were the leading cause of hip
fracture, Hwang et al. studied how the manner in which a fall occurs affects
the chances of hip fracture. In their study, they found three contributing
factors, with fall direction being the strongest predictor. During a sideways
fall, the chances of hip fracture see a 15-fold and 12-fold increase in elderly
males and females, respectively. This is likely due to a mechanical load
experienced by bones weakened by osteoporosis.
Diagnosis X-rays of the affected hip usually make
the diagnosis obvious; AP and lateral views should be obtained.
In situations where a hip fracture is suspected but not obvious on x-ray, an
MRI is the next test of choice. If an MRI is not available or the patient can
not be placed into the scanner a CT may be used as a substitute. MRI sensitivity
for radiographically occult fracture is greater than CT. Bone scan is another
useful alternative however substantial drawbacks include decreased sensitivity,
early false negative results, and decreased conspicuity of findings due to
age related metabolic changes in the elderly.
As the patients most often require an operation, full pre-operative general
investigation is required. This would normally include blood tests, ECG and
chest x-ray. = Types=
Prevention Hip protectors appear to decrease the
number of hip fractures among the elderly. They; however, are not often
used. Management
Most hip fractures are treated by implanting an orthosis. The surgery is a
major stress, particularly in the elderly. Pain is significant, resulting
in immobilization. Since prolonged immobilization can be more of a health
risk than the surgery itself, post-op people are encouraged to become mobile
as soon as possible, often with the assistance of physical therapy. Skeletal
traction pending surgery is not supported by the evidence. Regional
nerve blocks are useful for pain management in hip fractures.
If operative treatment is refused or the risks of surgery are considered to be
too high the main emphasis of treatment is on pain relief. Skeletal traction may
be considered for long term treatment. Aggressive chest physiotherapy is needed
to reduce the risk of pneumonia and skilled rehabilitation and nursing to
avoid pressure sores and DVT/pulmonary embolism Most people will be bedbound
for several months. Non-operative treatment is no longer an alternative in
developed countries with modern health care.
= Intracapsular fractures= For low-grade fractures, standard
treatment is fixation of the fracture in situ with screws or a sliding
screw/plate device. This treatment can also be offered for displaced fractures
after the fracture has been reduced... In elderly patients with displaced or
intracapsular fractures many surgeons prefer to undertake a hemiarthroplasty,
replacing the broken part of the bone with a metal implant. The advantage is
that the patient can mobilize without having to wait for healing.
In elderly patients who are medically well and still active, a total hip
replacement may be indicated. Traction is contraindicated in femoral
neck fractures due to it affecting blood flow to the head of the femur.
= Intertrochanteric fracture= An intertrochanteric fracture, below the
neck of the femur, has a good chance of healing. Treatment involves stabilizing
the fracture with a lag screw and plate device to hold the two fragments in
position. A large screw is inserted into the femoral head, crossing through the
fracture; the plate runs down the shaft of the femur, with smaller screws
securing it in place. The fracture typically takes 3–6 months
to heal. As it is only common in elderly, removal of the dynamic hip
screw is usually not recommended to avoid unnecessary risk of second
operation and the increased risk of re-fracture after implant removal. The
most common cause for hip fractures in the elderly is osteoporosis; if this is
the case, treatment of the osteoporosis can well reduce the risk of further
fracture. Only young patients tend to consider having it removed; the implant
may function as a stress riser, increasing the risk of a break if
another accident occurs. = Subtrochanteric fractures=
Subtrochanteric fractures may be treated with an intramedullary nail or a
screw-plate construction and may require traction pre-operatively, though this
practice is uncommon. It is unclear if any specific type of nail results in
different outcomes than any other type of nail.
= Rehabilitation= Rehabilitation has been proven to
increase daily functional status. It is unclear if the use of anabolic steroids
effects recovery. Complications
Nonunion, failure of the fracture to heal, is common in fractures of the neck
of the femur, but much more rare with other types of hip fracture. The rate of
nonunion is increased if the fracture is not treated surgically to immobilize the
bone fragments. Malunion, healing of the fracture in a
distorted position, is very common. The thigh muscles tend to pull on the bone
fragments, causing them to overlap and reunite incorrectly. Shortening, varus
deformity, valgus deformity, and rotational malunion all occur often
because the fracture may be unstable and collapse before it heals. This may not
be as much of a concern in patients with limited independence and mobility.
Avascular necrosis of the femoral head occurs frequently in fractures of the
neck of femur, because the blood supply is interrupted. It is rare after
intertrochanteric fractures. Hip fractures rarely result in
neurological or vascular injury. = Surgical=
Deep or superficial wound infection has an approximate incidence of 2%. It is a
serious problem as superficial infection may lead to deep infection. This may
cause infection of the healing bone and contamination of the implants. It is
difficult to eliminate infection in the presence of metal foreign bodies such as
implants. Bacteria inside the implants are inaccessible to the body's defence
system and to antibiotics. The management is to attempt to suppress the
infection with drainage and antibiotics until the bone is healed. Then the
implant should be removed, following which the infection may clear up.
Implant failure may occur; the metal screws and plate can break, back out, or
cut out superiorly and enter the joint. This occurs either through inaccurate
implant placement or if the fixation does not hold in weak and brittle bone.
In the event of failure, the surgery may be redone, or changed to a total hip
replacement. Mal-positioning: The fracture can be
fixed and subsequently heal in an incorrect position; especially rotation.
This may not be a severe problem or may require subsequent osteotomy surgery for
correction. = Medical=
Many people are unwell before breaking a hip; it is common for the break to have
been caused by a fall due to some illness, especially in the elderly.
Nevertheless, the stress of the injury, and a likely surgery, increases the risk
of medical illness including heart attack, stroke, and chest infection.
Blood clots may result. Deep venous thrombosis is when the blood in the leg
veins clots and causes pain and swelling. This is very common after hip
fracture as the circulation is stagnant and the blood is hypercoagulable as a
response to injury. DVT can occur without causing symptoms. A pulmonary
embolism occurs when clotted blood from a DVT comes loose from the leg veins and
passes up to the lungs. Circulation to parts of the lungs are cut off which can
be very dangerous. Fatal PE may have an incidence of 2% after hip fracture and
may contribute to illness and mortality in other cases.
Mental confusion is extremely common following a hip fracture. It usually
clears completely, but the disorienting experience of pain, immobility, loss of
independence, moving to a strange place, surgery, and drugs combine to cause
delirium or accentuate pre-existing dementia.
Urinary tract infection can occur. Patients are immobilized and in bed for
many days; they are frequently catheterised, commonly causing
infection. Prolonged immobilization and difficulty
moving make it hard to avoid pressure sores on the sacrum and heels of
patients with hip fractures. Whenever possible, early mobilization is
advocated; otherwise, alternating pressure mattresses should be used.
References: Prognosis
Hip fractures are very dangerous episodes especially for elderly and
frail patients. The risk of dying from the stress of the surgery and the injury
in the first thirty days is about 10%. At one year after fracture this may
reach 30%. If the condition is untreated the pain and immobility imposed on the
patient increase that risk. Problems such as pressure sores and chest
infections are all increased by immobility. The prognosis of untreated
hip fractures is very poor. = Post operation=
Among those affected over the age of 65, 40% are transferred directly to
long-term care facilities, long-term rehabilition facilities, or nursing
homes; most of those affected require some sort of living assistance from
family or home-care providers. 50% permanently require walkers, canes, or
crutches for mobility; all require some sort of mobility assistance throughout
the healing process. Among those affected over the age of 50,
approximately 25% die within the next year due to complications such as blood
clots, infections, and pneumonia. Patients with hip fractures are at high
risk for future fractures including hip, wrist, shoulder, and spine. After
treatment of the acute fracture, the risk of future fractures should be
addressed. Currently, only 1 in 4 patients after a hip fracture receives
treatment and work up for osteoporosis, the underlying cause of most of the
fractures. Current treatment standards include the starting of a bisphosphonate
to reduce future fracture risk by up to 50%.
Epidemiology Hip fractures are seen globally and are
a serious concern at the individual and population level. By 2050 it is
estimated that there will be 6 million cases of hip fractures worldwide. One
study published in 2001 found that in the US alone, 310,000 individuals were
hospitalized due to hip fractures, which can account for 30% of Americans who
were hospitalized that year. Another study found that in 2011, femur neck
fractures were among the most expensive conditions seen in US hospitals, with an
aggregated cost of nearly $4.9 billion for 316,000 inpatient hospitalizations.
Falling, poor vision, weight and height are all seen as risk factors. Falling is
one of the most common risk factors for hip fractures. Approximately 90% of hip
fractures are attributed to falls from standing height.
Given the high morbidity and mortality associated with hip fractures, and the
cost to the health system, in England and Wales the National hip fracture
database is a mandatory nationwide audit of care and treatment of all hip
fractures. = Population=
All populations experience hip fractures but numbers vary with race, gender, and
age. Women suffer three times as many hip fractures as men. In a lifetime, men
have an estimated 6% risk whereas postmenopausal women have an estimated
14% risk of suffering a hip fracture. These statistics provide insight over a
lifespan and conclude that women are twice as likely to suffer a hip
fracture. The overwhelming majority of hip fractures occur in white individuals
while blacks and Hispanics have a lower rate of them. This may be due to their
generally greater bone density and also because whites have longer overall
lifespan and higher likelihood of reaching an advanced age where the risk
of breaking a hip goes up. Deprivation is also a key factor: in England it has
been found that people in the poorest parts of the country are more likely to
fracture a hip and less likely to recover well than those in the least
deprived areas. = Age related=
Age is the most dominant factor in hip fracture injuries, with most cases
occurring in people over 75. The increase of age is related to the
increase of hip fractures incidences. Falls are the most common cause of hip
fractures, around 30-60% of older adults fall each year. This increases the risk
for hip fracture and leads to the increase risk of death in older
individuals, the rate of one year mortality is seen from 12-37%. For those
remaining patients who do not suffer from mortality, half of them need
assistance and cannot live independently. Also, older adults
sustain hip fractures because of osteoporosis, which is a degenerative
disease due to age and decrease in bone mass. The average age for suffering a
hip fracture is 77 years old for women and 72 years old for men. This shows how
closely age is related to hip fractures. References
External links Orthopedics.com article on hip fractures
Fractures of the Femoral Neck Wheeless Textbook of Orthopaedics
Intertrochanteric Fractures Wheeless' Textbook of Orthopaedics
National Hip Fracture Database National Hip Fracture Database
Proximal femoral fracture Musculoskeletal Radiology of Fractures
National Osteoporosis Society National Osteoporosis Society