The structure of the head and neck of femur is developed for the
transmission of body weight efficiently, with minimum bone mass, by
appropriate distribution of the bony trabeculae in the neck. The
tension trabeculae and compression trabeculae along with the strong
calcar femorale on the medial cortex of the neck of the femur form
an efficient system to withstand load bearing and torsion under
normal stresses of locomotion and weight bearing.
In old age, osteoporosis of the region occurs. The incidence of
fracture neck of femur is higher in old age.
Blood supply to the head and neck of femur
The profunda femoris artery arising from the femoral artery
gives off medical circumflex femoral artery. This gives off the
lateral epiphyseal and superior and inferior metaphyseal arteries.
The lateral epiphyseal arteries are important and supply the
laterial 2/3 of the femoral head. The superior metaphyseal artery
supplies the superior aspect of the femoral neck. The inferior
metaphyseal artery supplies the inferior part of the neck and the
adjacent part of the head derived from the metaphysis.
The medial epiphyseal artery supplies a circumfoveal sector of the
head. It is a continuation of the artery of the ligamentum teres
which arises from the acetabular branch of the obturator artery.
Femoral neck fractures that are intracapsular and may threaten
any or all of the three sources of blood to the femoral head:
- the cervical vessels in the retinaculum of the joint capsule -
usually damaged if the fracture is displaced
- intramedullary vessels - always torn
- from the ligamentum teres - usually contributes minimally in
the elderly and not uncommonly, may be non-existent
In addition to the damage to the blood supply, the intracapsular
nature of the fracture hinders recovery from the injury:
- intra-articular bone has only a thin periosteum and has no
contact with soft tissues - the response to injury - callus
formation - is weak
- blood remains inside the joint capsule, increasing
intracapsular pressure and further damaging the femoral head;
synovial fluid hinders clotting
Incidence and Mechanism
The fracture of the neck of femur is common in the elderly. It
does occur occasionally in young adults and even in children. It
occurs more frequently in women. In India, the incidence of
fracture neck of femur in children is higher than in the Western
The fracture may result either from rotation violence at the hip due
to tripping over something on the floor and falling or a direct
violence over the lateral aspect of the hip by a fall on the side.
Two broad groups of fractures are recognised in the neck
(1) Intracapsular fractures (2) Extracapsular fractures.
This is diveded according to the level of the fracture line in
the neck as follows.
There are all grouped as Trochanteric fractures of various
NECK OF FEMUR
This is also called a high fracture neck of femur. In this
group, the proximal fragment often loses part of its blood supply
and hence, the union of this fracture is difficult. This is a
serious injury in the elderly patient. In the very old and
debilitated person, it can precipitate a crisis in the precarious
metabolic balance. It can become a terminal illness due to uremia,
lung infection, bed sores etc, and be fatal.
This classification relies only upon the appearance of the hip
on the AP radiograph. It is used to determine the appropriate
- stage I : incomplete fracture of the neck (so-called abducted
- stage II : complete without displacement
- stage III: complete with partial displacement: fragments are
still connected by posterior retinacular attachment; there is
malalignment of the femoral trabeculae
- stage IV : this is a complete femoral neck fracture with full
displacement: the proximal fragment is free and lies correctly in
the acetabulum so that the trabeculae appear normally aligned
are classified along two continuums: the Pauwels and Linton
Type I has an obliquity ranging from 0 to 30 degrees
Type II has an obliquity ranging from 30 to 50 degrees
Type III has an obliquity of 70 or more degrees
The greater the
obliquity in the fracture, the higher the chances of either delayed
or nonunion. This woman's fracture is Pauwels Type II and therefore
has an intermediate chance of delayed or nonunion.
Stage I: Incomplete fracture
Stage II: Complete but undisplaced fracture
Stage III: Complete, partially displaced fracture
Stage IV: Displaced and totally free fracture
The patient is usually an elderly person with a history of a
fall and inability to walk. On inspection, the injured led lies in
a position of external rotation and there is shortening of the leg.
The attachment of the capsule to the distal fragment prevents
excessive external rotation of the leg. On palpation, there is
tenderness over the anterior and lateral aspects of the hip joint.
The greater trochanter is elevated on the injured side. All
movements are extremely painful except in the rare case of an
impacted type of fracture.
An anteroposterior view of the whole pelvis to show both
the hips must be taken. It shows the level and the type of
fracture. The subcapital and transcervical fractures are divided
into three types according to the obliquity of the line of fracture
(Pauwel). This is expressed as the angle formed by the line of the
fracture with the horizontal line (Pauwel's angle).
Type I: Pauwel's angle is less than 30 degrees, the fracture line
is nearer the horizontal.
Type II: The angle is between 30 and 70 degrees.
Type III: The angle is more than 70 degrees and the fracture line is
nearer the vertical.
In the more vertical fractures, the action of the gluteal and
adductor museles produces a shearing force on the fracture
line and hence nonunion is commoner. Thus, prognosis is worse in
Type III and good in Type I.
(Following imaging info from http://www.emedicine.com)
Radiography is the preferred initial imaging modality in
evaluating femoral neck fractures because of its near universal
availability, ease of acquisition, and documented correlation with
surgical results over many years of use.
However, radiography has some limitations. Spiral fractures are
difficult to assess on a single view. Comminution is also not as
easily demonstrated as it is with CT. Some stress fractures are
simply not visible on plain images at all. However, radiography will
likely remain the mainstay in the evaluation of these injuries in
the near future, and cross-sectional imaging will play an increasing
but supplementary role.
False Positives/Negatives: Some femoral neck fractures are not
visible on radiographs obtained during the initial evaluation. If
the clinical suspicion is strong, these cases can be further
evaluated with MRI, which shows bone marrow edema, or nuclear
medicine bone scanning, which shows increased tracer uptake. The
latter is much less expensive than MRI and nearly as sensitive. The
major drawback of bone scanning is in the first 48-72 hours after
trauma, when its sensitivity is lower than that of MRI.
CT plays an increasingly important role in evaluating the hip
after a fracture. CT is exquisite useful for imaging abnormalities
of the bone itself. Because of its superior resolution,
cross-sectional capabilities, and amenability to image
reconstruction in the coronal and sagittal planes, CT is useful for
assessing fracture comminution preoperatively and in determining the
extent of union (or lack thereof) postoperatively.
Degree of Confidence: CT is the most useful test for evaluating bony
injury. However, axial fractures in the plane of the images can on
occasion be missed with CT. This potential is decreased with the use
of images reconstructed in orthogonal planes and newer multidetector
MRI is both sensitive and specific in the detection of
femoral neck fractures, because it can show both the actual fracture
line and the resulting bone marrow edema. The superior contrast of
MRI when appropriate pulse sequences are used, the intrinsic spatial
resolution, and the ability to image in multiple planes (coronal,
axial, and less commonly, sagittal) makes MRI the premiere imaging
modality, especially in the setting of stress fractures, which can
appear normal on initial plain images.
Popular pulse sequences include coronal and axial T1-weighted and
T2-weighted fat-suppressed sequences, although several other bone
marrow sequences can also be used. In practice, a large field of
view is usually used so that both hips and the bony pelvis can be
imaged simultaneously. Intravenous contrast enhancement is not
routinely used in the assessment of fractures. The fracture line can
be visualized as linear low-signal-intensity areas surrounded by
bone marrow edema, which is hypointense relative to normal marrow on
T1-weighted images or hyperintense on T2-weighted images.
Drawbacks of MRI include its longer imaging time, its relative lack
of widespread availability, its higher costs, and the exclusion of
patients with cardiac pacemakers and certain metal hardware in their
body. With continued technological advances the imaging time has
decreased, as have the costs, making MRI more cost-effective.
MRI is the most sensitive modality in detecting bone marrow changes
related to avascular necrosis, even when radiographic findings are
normal; therefore, MRI is the imaging modality of choice in this
regard. When avascular necrosis is detected after surgical fixation
for a femoral fracture, the patient can become a candidate for
placement of a prosthesis. More importantly, MRI can be used to
detect early stages of ischemic necrosis in the femoral head, where
interventions can be initiated before further damage can occur. Such
damage may include femoral head collapse, secondary osteoarthritis,
MRI is currently the best imaging modality for detecting femoral
neck fractures. Several facts must be kept in mind, however. The
normal bone marrow of the pelvis and hips can have a patchy
intermediate-signal-intensity appearance corresponding to the
persistence of red marrow. Also, the subchondral area of the femoral
head can sometimes have a thin rim of red marrow. These normal
variants should not be confused with fractures.
Fractures and contusions should not be confused with idiopathic
transient osteoporosis of the hip. This is an uncommon, self-limited
disease that affects middle-aged men and pregnant women. It appears
as osteopenia on plain radiographs and as areas of decreased T1
signal intensity and increased T2 signal intensity which generally
extends from the femoral head to the intertrochanteric line on MRI.
Usually, only one hip is affected at a given time. To complicate
matters, transient osteoporosis can predispose patients to a
fracture if proper care (eg, protected weight bearing) is not
implemented. ULTRASOUND Section 7 of 12
Author Information Introduction Differentials X-ray Cat Scan MRI
Ultrasound Nuclear Medicine Angiography Intervention Pictures
Ultrasonography does not play a significant role in the
routine evaluation of hip fractures. However, it has been used in
research to evaluate the degree of distention of the hip joint
capsule after fractures and in the study of elevated intracapsular
pressures. Sonograms can also depict the presence of an
intracapsular hematoma, which is mildly echogenic, as distinguished
from synovial fluid, which is anechoic
Findings: Approximately 80% of fractures can be visualized 24 hours
after trauma, as seen by diffusely increased tracer uptake. By 3
days after trauma, 95% of fractures are visualized, and maximal
fracture sensitivity is found at 7 days; this knowledge may be
helpful in equivocal cases. Given the high sensitivity of nuclear
medicine studies, they can be used to diagnose suspected femoral
neck fractures not confirmed by means of plain radiography.
Nuclear medicine studies with technetium-99m methylene diphosphonate
(99mTc-MDP) have also been found to be effective in predicting
healing complications related to femoral neck fractures. Stromqvist
et al have demonstrated that 99mTc-MDP bone scans of the hips
performed within 2 weeks after fixation surgery for femoral neck
fractures have an excellent prognostic value for future fracture
redisplacement, nonunion, or segmental femoral head collapse.
Although sensitive, bone scintigraphy is not specific for fractures.
Other processes such as infection, inflammation, or tumor formation
can also demonstrate increased uptake. However, in the right
clinical setting (eg, known trauma), it is highly sensitive for the
detection of fractures.
Fractures at this level have a poor capacity for union due to
the following factors.
a) interference with the blood supply to the proximal fragment.
b) difficulty in controlling the small proximal fragment.
c) the lack of organisation of the fracture haematoma due to the
presence of the synovial
Two essential principles to be followed in the surgical
management of this fracture are
(a) perfect anatomical reduction. (b) rigid internal fixation.
The earlier method of stabilising the fracture was by internal
fixation with Smith Petersen Trifin nail. The fracture is reduced
by manipulation with the patient in a special orthopaedic table.
The fracture is internally fixed with an S.P. Nail under
The more recent method of internal fixation of the fracture is the
use of multiple compression screws
Dynamic Hip Screw
In older patients above 60 years, such fractures are treated by
removing the head of the femur and replacing it by metal prosthesis
like Austin Moore's prosthesis. This enables the patient to be
ambulant and start early weight bearing.
Fracture neck of femur in Children
The fracture is reduced by manipulation and the leg immobilised
in full plaster spica in abduction for 8-10 weeks. When indicated
internal fixation could be done with multiple thin Austin Moore's
Complications of Fracture Neck of Femur
The important complications are: a) Non-union b) Avascular
necrosis of head of femur.
Failure of union of this fracture still occurs due to improper
reduction of imperfect internal fixation. When this occurs, the
patient complains of pain and develops instability on walking. The
condition is treated by intertrochanteric osteotomy (McMurray) in
the younger age group and replacement arthroplasty in the elderly.
In the very old patient with poor general condition, the
only treatment possibly may be to keep the leg between sand bags and
attend to the general care of the patient. As soon as the general
condition is restored and the local pain relieved, physiotherapy is
started. Movements of the hip are encouraged and the patient is got
up on crutches about three weeks after the injury. Gradual weight
bearing will lead to painless nonunion. This end result is
practicable and is still useful in our country, in places where good
surgical and hospital facilities are not available.
Avascular necrosis of the head of the femur is an unpredictable
complication met with after any type of internal fixation. The
patient presents with pain in the hip and limping. There is
limitation of all movements of the hip with muscle spasm.
Radiography shows patchy areas of increased density in the head of
the femur. Treatment in the early stages is by rest, traction and
weight relieving caliper. When indicated, osteotomy or replacement
arthroplasty is done.
TROCHANTERIC FRACTURE OF FEMUR
(Extra Capsular Fracture neck of femur)
These are also called low fractures and are again classified as
(i) Stable, (ii) Unstable fractures. In this group, the blood
supply to the proximal fragment is not interfered with and there is
a greater area of contact between the two fragments; hence the
fractures unite easily. While union is the rule, it is common to
see these fractures malunited with a coxa vara deformity.
The normal neck shaft angle is about 115 degrees. When the angle
is reduced to nearer
90 degrees, the deformity is called Coxa Vara.
These fractures occur in the elderly and the nature of the
violence is the same as in the intracapsular fracture.
On examination, the injured leg lies externally rotated and is
obviously shorter. The degree of external rotation is greater than
in the intra capsular fracture. There is marked local swelling and
echymoses over the trochanteric area. All movements of the hip are
extremely painful and limited. This has to be differentiated from
common More common
Causative violence Minimal rotation
violence Lateral violence
Minimal Fully externally
Nil Marked local
Common Does not occur
Stable Type: There is a single
fracture line and it is a two piece fracture.
Unstable Type: This is a comminuated
fracture with multiple fractures at the trochanteric level
The principle of the treatment is reduction of the fracture and
maintenance of the fragments in good position till union occurs.
This consists of the application of continuous skeletal
traction. For cases with marked coxa vara, continuous skeletal
traction through the upper tibia is applied and the leg is
immobilised in the Bohler Braun splint and the foot end of the bed
is raised. Traction with 12 to 15 Ibs is sufficient. The coxa vara
gets corrected and the fracture unites in about 12 weeks. When the
coxa vara is not marked, skin traction in Thomas' splint will
be sufficient. Excepting the fact that the patient occupies a
hospital bed for about 3 months, there is no other serious defect in
this conservative method and the results are highly satisfactory.
This consists of manipulative reduction and internal fixation.
The internal fixation is done by a nail plate as shown in the
figure. The McLauglin two piece nail plate has been commonly used.
The use of a single piece angled nail plate (Jewett) has been found
to be mechanically superior and gives good results. More recently
the use of compression hip screw and plate system has enabled
earlier mobilisation of the hip and weight bearing.
The main complication is malunion with coxa vara and
shortening. If the coxa vara is gross, it can be corrected by
The death rate within one year of fractured neck of femur is
typically reported as between 20% and 35%.Performance indicators
based on mortality after hospital admission for such fractures have
been promoted.The only measure of mortality in routine hospital
statistics, however, is “in-hospital mortality”—death during the
initial admission for the fracture. We analysed inpatient statistics
that had been linked to death registration data in the former Oxford
NHS health region (population 2.5 million) from 1994 to 1998. (BMJ. 2002
October 19; 325 (7369): 868–869)
Exploring the Outcomes of Fractured Neck of Femur
Identifying the Key Actors
The outcomes of
interventions for fractured neck of femur can be explored in five
types of service (prevention, access to hospital setting and initial
diagnosis, actual treatment episode and subsequent hospital based
recovery, recovery in the community, longer term recovery) and at
four possible time periods (prior to fracture, early treatment,
first three months, longer term).
There are a wide range of groups whose outcomes need to be
considered, including the patient, carer, clinicians, managers and
purchasers. Some will have a major interest throughout - the
user/patient - while others will be primarily interested in shorter
term outcomes (for example, the hospital team) or in longer term
outcomes (the potential carer, the primary care team and other
health and social services).
Examples of the desired outcomes for the user,
hospital team and purchaser are outlined in Table 1. As many
patients with hip fracture may have other (pre-existing) ill-health
problems, their assessment and implications for achieving best
desirable outcomes need to be explored. From the patient's
perspective, getting the process right may be most
critical, suggesting the key role for measurement of satisfaction
with the care, treatment and achieved outcome. For patients with
pre-existing co-morbidity, desired outcomes will relate to potential
change in their level of dependency and thus possible consequences
for (informal) carers.
When Should the Outcomes be Measured?
time periods will depend on the particular use for the outcomes
data. Within routine patient care, achieved outcomes need to be
assessed at discharge, in the subsequent three months and, for those
with pre-existing or consequent co-morbidity, in the longer term, as
part of the ongoing provision of care. It is important to measure
and record pre-fracture mobility as a baseline measurement for
comparison with the situation post-fracture.
Matching Measures to Desired Outcomes
pre-fracture and post-fracture mobility are central to any
assessment of outcomes. These can be assessed by use of a measure of
physical aspects of daily living (Freeman et al, 1995), a measure of
instrumental/extended activities of daily living (shopping, use of
public transport), use of a walking scale or short mobility scores
(Keene et al, 1993), together with the use/need for walking aids
(both prior and subsequent to the injury). The range of measures
that have been used in research and audit studies are summarised in
Table 2. Some key points to note are:
- Measures of impairment and disability predominate, both
because they are easy to measure and valuable for assessing
- There may be a useful role for multi-dimensional health
profiles in broadening the focus of measurement to the
consequences of the fracture for the individual user, especially
as few of the measures address explicitly patient
defined/specified desired outcomes.
- Mortality and the ability to return home (defined as the
patient's usual address) have been used as prime indicators at a
population level (CRAG, 1994; Department of Health, 1993). Ability
to return home will depend on a number of factors including
walking ability, available formal health and social service
support and informal carer support, and, for those coming from
residential accommodation, the ability of the residential home to
meet any additional (higher dependency) needs of the patient.
- For patients with pre-existing co-morbidity, changes in
dependency must be assessed. Pre-existing and subsequent levels of
handicap and implications for (informal) carers need to be (re-)
For patients with pre-existing co-morbidity, a fractured hip may
accentuate the level of dependency; for others, the fracture may
form a transition point towards greater dependency. In both
situations, the consequences for informal carers (friend, neighbour
or relative) must be recognised, suggesting the need for the
assessment of long term disability and handicap. Possible scales
include the London Handicap scale or the Functional Autonomy
Measurement Scale (Harwood et al, 1994). Alternatively, the
individual components of handicap could be assessed, most
particularly any lack of mobility and its subsequent implications,
mental health and social functioning or isolation.
There is a range of factors that need to be taken into account in
interpreting aggregate outcomes data for fractured neck of femur.
- pre-fracture ADL/walking ability
- existing patient co-morbidity and level of frailty
- type of fracture (intracapsular or extracapsular)
- level of support at home
- other characteristics of the patient (age, socio-economic
status, source of admission).
Information needs to be collected on these potentially
confounding variables, to allow for their control in any comparative
analysis and to enable sound interpretation of the indicators. If
length of stay targets (a process measure) are set by purchasers,
these also need to be adjusted for case severity adjustment. Setting
inappropriate targets will reduce the quality and impair the patient
outcome (Beech et al, 1995).