Fracture neck of Femur: Diagnosis and
What is a femoral neck fracture?
A fracture through the intra articular part of the
femoral neck is usually referred to by the term femoral
Another term is intracapsular proximal femoral
fracture. About 80% of these fractures are displaced.
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
ANATOMY OF NECK OF FEMUR
Neck connects head with shaft
and is about 3.7 cm long.
It makes angle with the shaft
130+/- 7 degree( less in female
due to their wider pelvis).
It facilitate movements of hip joint.
It is strengthened by calcar
femorale (bony thickening along
2 borders and 2 surfaces
Upper border –concave and horizontal meets the shaft at
Lower border – straight and oblique meet the shaft at
Anterior surface- flat .meet shaft at intertrochanteric line
. Entirely intra capsular.
Posterior surface- convex from above downwards and
concave from side to side.meets shaft at intertrochanteric
crest.it is crossed by horizontal groove for tendon of
Crock described the arteries of the proximal end
of the femur in three groups
(a) an extracapsular arterial ring located at the base of
the femoral neck;
(b) ascending cervical branches of the extracapsular
arterial ring on the surface of the femoral neck (known
as retinacular arteries)
(c) the arteries of the ligamentum teres
The extracapsular arterial ring is formed
posteriorly by a large branch of the medial
femoral circumflex artery and anteriorly by
branches of the lateral femoral circumflex artery .
The superior and inferior gluteal arteries also
have minor contributions to this ring
b) The ascending cervical arteries can be
divided into four groups
(anterior, medial, posterior, and lateral) based on
their relationship to the femoral neck.
lateral group provides most of the blood
supply to the femoral head and neck.
The artery of the
ligamentum teres is a
branch of the obturator
or the medial femoral
circumflex artery only
small & variable
amount of femoral
head is nourished by
artery of ligamentum
Most fracture are displaced with
distal fragment – externally rotated, adducted,
and proximall migrated.
These displacement are less marked than in
intertrochanteric fracture because the capsule of hip
joint is attached to distal fragment and prevent extreme
rotation and displacement of distal fragment.
Basicervical (base of the neck fracture)
This is based on the angle of fracture from the
Type I: 30 degrees
Type II: 50 degrees
Type III: 70 degrees
As the fracture progresses from type 1 to type 3, the
obliquity of the fracture line increases, thus the shear
force at the fracture site increases.
This is based on the degree of valgus
Type I: Incomplete/valgus impacted
Type II: Complete and nondisplaced on AP and
Type III: Complete with partial displacement;
trabecular pattern of the femoral head does not line up
with that of the acetabulum
Type IV: Completely displaced; trabecular pattern of
the head assumes a parallel orientation with that of the
Orthopaedic Trauma Association (OTA)
B1 group fracture is nondisplaced to minimally
displaced subcapital fracture
B2 group includes transcervical fractures through the
middle or base of the neck
B3 group includes all displaced nonimpacted
MECHANISM OF INJURY
Low-energy trauma (most common in older patients)
- Direct: A fall onto the greater trochanter (valgus
impaction) or forced external rotation of the lower
extremity impinges an osteoporotic neck onto the
posterior lip of the acetabulum (resulting in posterior
- Indirect: Muscle forces overwhelm the strength of the
High-energy trauma- accounts for femoral neck
fractures in both younger and older patients, such as
motor-vehicle accident or fall from a significant
Cyclical loading-stress fractures: These are seen in
athletes, military recruits, ballet dancers; patients with
osteoporosis and osteopenia are at particular risk.
Situations in which femoral neck fracture may be
missed Stress fractures- elderly patient with unexplained pain
in the hip should be considered to have stress fracture
until proven otherwise.
Undisplaced fracture-impacted fracture may be
difficult to visualise on plain x-ray.
Painless fracture-a bed ridden patient may develop a
Multiple fractures-patient with a femoral shaft
fracture may also have a hip fracture which is
easily missed unless the pelvis is x- rayed.
the preferred initial
imaging modality in
evaluating femoral neck
fractures because of its
availability, ease of
with surgical results
over many years of use.
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.
CT plays an increasingly important role in evaluating the
hip after a fracture.
CT is exquisite useful for imaging abnormalities of the
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 CT scanners
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.
The fracture line can be visualized as linear low-signalintensity 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
Its higher costs, and the exclusion of
patients with cardiac pacemakers and certain
metal hardware in their body.
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
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.
Fractures at this level have a poor capacity for union
due to the following factors.
Interference with the blood supply to the proximal
Difficulty in controlling the small proximal fragment.
The lack of organisation of the fracture haematoma
due to the presence of the synovial fluid.
Surgical Treatment :
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 radiological control.
The more recent method of internal fixation of the
fracture is the use of multiple compression screws.
Fracture neck of femur in older patients
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 Pins.
Dynamic Hip Screw:
•Most commonly used
device for both stable
and unstable fracture
•Plate angle is variable
130 to 150 degrees.
•Has to be positioned
centrally in the femoral
•Use of radiological
views to know the exact
Total hip joint
Broad treatment guidelines
• More than 70 years
• Young adults
Multiple Moore`s pinning
• DHS = dynamic hip screws
• THR = total hip replacement
• Multiple Moore`s
Thromboembolism : - leading cause of death within
first 7 days ( 40 % )
Failure of union of this fracture still occurs due to
improper reduction of imperfect internal fixation.
Nonunion rate 85 – 95 %
If there is no evidence of radiological healing taking
place between 6 and 12 months at treatment on a
radiograph , it is declared as nonunion.
Causes : Inaccurate reduction
Poor internal fixation
Avascularity of femoral head
Clinical features : Unable to bear the weight on the affected side
Wasting of the muscles
Minimal shortening of the affected lower limb
Avascular necrosis of the head of the femur is an
unpredictable complication met with after any type of
The patient presents with pain in the hip and limping.
There is limitation of all movements of the hip with
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.