Femoral Neck Fractures - ED Central
Transcript of Femoral Neck Fractures - ED Central
FEMORAL NECK FRACTURES
Left: Casts of caryatids at the Erechtheion temple on the Acropolis, Athens. Right caryatid, in
marble, Fifth Century (c. 480) B.C, British Museum.
“Mighty indeed are the marks and monuments of our Empire which we have left. Future ages
will wonder at us, as the present age wonders at us now…”
Pericles, Fifth Century BC
The only surviving major written work on architecture from antiquity is that of the great
Roman architect Vitruvius. His “De architectura”, is a treatise written in both Latin and
Greek consisting of ten books which he dedicated to the Emperor Augustus. There would not
be a comparable work for over one thousand four hundred years, when the Renaissance master
Leon Battista Alberti updated and refined Vitruvius’ work.
Vitruvius insisted that all architecture should have three qualities, strength and durability,
usefulness and beauty. Noble sentiments, not always reflected in the current age! He believed
that architecture should imitate nature, as birds built their nests and bees built their hives, so
too did humans build from the natural materials around them. He studied the great Greek
architects of previous centuries and marvelled at their philosophies of ideal proportions,
according to mathematically precise principles. They developed three distinct architectural
orders, the Doric, the Ionian and the Corinthian, different approaches to creating buildings
that were not only precisely mathematically proportioned but also exquisitely beautiful.
Classical Greek architecture reached its apogee in the golden age of Pericles. The Greek
structures were the marvel and envy of the ancient world. Pericles himself had no doubt that
future generations far into the future would marvel at them. He was not mistaken. Even though
the millennia have taken a severe toll, there is no doubt that the monuments that have survived
from the age of Pericles were useful, durable and above all beautiful.
Vitruvius believed that a deep understanding of proportions was one of the noblest
achievements of architecture. He therefore strove to understand the greatest architecture of all
in nature - humanity, which in turn imitated the proportions of the gods themselves. He studied
the human body in terms of its proportions and by so doing arrived at what he considered to be
the ideal arrangement of the human body. This idea has survived to the modern age, thanks to
a brilliant man of the Renaissance who after studying the architectural texts of antiquity,
mathematically reconstructed a man in the Vitruvian ideal. His name was Leonardo da Vinci,
and one of his cultural legacies, was the Western ideal of what constitutes beauty, the
mathematically precise ideal proportions of his “Vitruvian Man”
Unfortunately a large percentage of humanity does not quite conform to the high standards of
classical proportion of the Age of Pericles. Despite this there does seem to be a primal cultural
image imprinted in the subconscious of what beauty is. Most can say when they see a beautiful
form, yet when pressed to explain exactly what it is that constitutes beauty they are hard
pressed to do so. Perhaps it is the relative proportions of the “ideal” body that the architects
of antiquity strove to imitate in their monuments and buildings.
When we see a patient with a fractured hip, the diagnosis is often immediately apparent. The
foreshortened and externally rotated limb presents a striking and immediately apparent
deviation from our subconscious template of the Vitruvian man. In more subtle cases this sign
may not be apparent. We may not even see evidence of fracture on plain radiography - but our
subconscious may detect a more subtle disturbance in the architecture of the bones. Our innate
sense of “perfect proportions” is somehow offended. A closer examination of Shenton’s line
may reveal the reason for this offense.
FEMORAL NECK FRACTURES
Introduction
Femoral neck fractures are an extremely common presentation to the ED.
Virtually all will require operation.
Femoral neck fractures in the elderly are associated with significant longer term morbidity and
mortality. Twelve month mortality rate is around 25% and most survivors do not return to the
level of mobility and independence they had before the fracture. 1
Pathophysiology
Femoral neck fractures occur for two important reasons:
1. Osteoporosis, especially in elderly females.
2. Pathological fracture, usually due to secondary metastatic deposits within the neck
of the femur.
Complications:
The most important complications will be:
1. Avascular necrosis of the femoral head. 2
Intracapsular fractures (1) are especially likely to result in avascular necrosis of the
femoral head. The main supply of penetrates the head close to the cartilage margin (2)
and arises from an arterial ring (3) that is fed from the lateral and medial femoral
circumflex arteries (4,5). A small portion of the head is inconstantly supplied via the
ligamentum teres, (6). Extracapuslar fractures are less likely to result in this
complication.
2 Complications relating to prolonged immobility before discovery that is commonly
seen in the elderly as a result of these fractures
Elderly patients with femoral neck fractures have often spent a prolonged period of
time on the ground unable to move due to their injury, before being discovered by
friends / relatives.
Important complications may follow from this including:
● Dehydration
● Rhabdomyolysis
● Pressure necrosis areas.
● Hypothermia
● Hypoglycemia
3. Post operative and rehabilitation complications, including:
● Pneumonia
● UTI
● Confusion
● Pressure sores
● Pulmonary embolism
Clinical Assessment
Important points of history:
1. Mechanism of injury.
● Or did some other problem cause the fall in the first place, such as vasovagal or
collapse due to other causes.
2. Mobility before this event
3. Social circumstances, eg nursing home or hostel or home, including ability to cope.
4. Medications and allergies.
5. Routine past history.
6. Establish how long a patient as been on the ground before being discovered.
Important points of examination:
1. Lower limb on the injured side may be shortened and externally rotated but these
classical signs may not be present with impacted or lesser degrees of fracture.
Typical appearance of a fractured right neck of femur. The injured limb is shortened and
externally rotated. 4
2. Hip is locally tender to palpation and passive movement produces pain.
3. Look for other injuries.
4. Look for possible complications of prolonged immobility as listed above.
5. Weight bearing:
● Note that the ability of a patient to weight bear, does not necessarily rule out the
possibility of a fracture. A subtle “hairline” type fracture may exist.
Important Clinical Scenarios to note:
1. Representations:
● Plain x-rays should still be done in the first instance in these cases even if initial
x-rays appeared to be normal, as with time displacement and/ or callus
formation will make the fracture more obvious.
2. Normal plain radiology:
Note that if a fracture is not seen on x-ray, an impacted or minor femoral neck fracture
is not necessarily excluded.
● If a patient has normal x -rays, yet continues to complain of hip pain and
especially if they are unable to weight bear, then there should be a more
aggressive search for a fracture.
● In these cases, CT or MRI scan should be done.
3. A common presentation to the ED is the elderly confused / demented patient who
presents in apparent pain or inability to walk or having fallen to the ground and is
unable to walk.
● Often there will be little (or no) indication that they are suffering from hip pain
and a high index of suspicion must be maintained in these cases for femoral
neck fracture.
● Pelvic and bilateral hip x-rays should be taken.
4. Occasionally subtle pelvic rami fractures are missed when hip fractures are suspected.
The clinician’s attention is focused solely on the hip and a subtle ramus fracture is
therefore missed.
● Pelvic rami fractures should always be carefully looked for, especially when no
hip fracture is apparent yet the patient complains of “hip” pain and cannot
weight bear.
Investigations
Blood tests
● FBE
● U&ES / glucose, (urgent potassium if rhabdomyolysis is suspected)
● X-match 2 units of blood.
● CK, if the patient has been on the ground for a prolonged period, (rhabdomyolysis)
CXR
● In all cases (as a pre-op assessment)
ECG
● As a pre-op assessment
● For hyperkalemia, if rhabdomyolysis is suspected.
Plain radiography:
The diagnosis is usually confirmed with pelvis x-ray and hip x-ray.
For a classification of fractured neck of femur, see Appendix 1 below.
Generally the fracture line will be obvious, but in more subtle cases look for:
● Asymmetry in Shentons’s line (below) on the A-P (as compared to its opposite side).
Shenton’s line is a line drawn alone the inferior margin of the neck of the femur
continuing onward to the inferior border of the superior ramus of the pubis.
This line should be a smooth continuous curve.
If it is not or if it is significantly different from its opposite side then a femoral neck
fracture should be suspected.
Shenton’s Line.5
● On the lateral, look for angulation of the head with respect to the neck (2 below) or
subtle discontinuity of the margins (3 below).
Also look for subtle:
♥ Disruptions in trabecular markings.
♥ Hyperlucent lines of impaction.
CT scan
● Beware the apparently normal x-ray in the elderly with hip pain. Subtle impacted
fractures can be difficult to detect on plain radiology.
● If clinical suspicion remains, then CT scan should be done to confirm the diagnosis.
MRI
● This may also be considered, especially for the detection of suspected occult femoral
neck fractures where plain radiography is not diagnostic, yet clinical suspicion remains
high.
● This is the best imaging modality. It has virtually 100% sensitivity and specificity,
however access is usually more limited than CT scan.
Left: Plain radiograph of the left hip of an 87 year old male suffering from hip pain 2 weeks
after a fall. Diffuse osteopenia is seen but without any evidence of fracture. Right: MRI
revealed a non-displaced fracture line of the inter-trochanteric region. 6
Bone scan
● This may also confirm the diagnosis, however whilst it is very sensitive for a
fracture it is not as specific as CT or MRI
● It should further be noted that bone scans take time to become positive. In the young
this may be only 24-48 hours, however in the elderly the scan may make take up to one
week to become positive.
Management
1 Analgesia:
● Opioid analgesia / anti-emetic as indicated.
2. Nil orally:
● Keep the patient fasted in the first instance, (until a definite theatre time has
been established).
3. IV fluids:
Fluids should be commenced because:
● Often there has been a prolonged “down time” until the patient has been found,
hence they will be dehydrated.
● Preoperative fasting. Time to operation may be prolonged.
The rate should be titrated to each patient’s individual needs.
4. Regional anaesthesia:
It should be noted that the hip joint receives nervous innervation from multiple nerves,
including the femoral, lateral femoral cutaneous and the obturator nerve. This makes
complete anaesthesia of the hip joint via regional techniques problematic, however
some good effect can be achieved with various techniques that will often reduce the
amount of parenteral analgesia required.
Techniques include:
Femoral nerve block:
● This will give some, but not complete, effect.
Femoral nerve 3 in 1 block:
● This is a modified femoral nerve block, whereby a little extra anaesthetic is used
together with pressure distal to the site of injection. The aim is to encourage the
spread of anaesthetic through fascial planes in order that some reaches the,
lateral femoral cutaneous and the obturator nerves.
Fascia Iliaca Block:
● A modified technique that aims to more carefully identify the fascial planes and
so to more precisely deliver the local anaesthetic agent.
5. DVT prophylaxis: 7
● Clexane prophylaxis should be given, 40mg SC (or 20mg in patients with renal
impairment), in accordance with local VTE prevention guidelines.
● If clexane is contra-indicated, aspirin may be used.
● Pressure gradient stockings should be used.
Note however that clexane contraindicates a spinal anaesthetic for a minimum
period of 12 hours. If a spinal anaesthetic is to be given within 12 hours then
clexane should not be commenced. Other DVT prevention strategies such as
mechanical calf stimulators can be used.
The exact timing of initiation of clexane for DVT prophylaxis must therefore be a
decision for the Anaesthetic Unit in conjunction with the Orthopaedic Unit. It will
depend on whether the patient is having their operation under a spinal anaesthetic
or under a general anaesthetic, as well as the timing of when the operation is to
take place.
6. There is no evidence to support the use of pre-operative traction. 1
7. Surgery:
● Virtually all cases will require operative fixation.
● Surgery should ideally occur within 36 hours to reduce the incidence of
complications such as confusion, pneumonia and pressure sores. 1
● Regional anaesthesia is recommended for most patients.
Disposition
● Orthopedic Unit admission
● Orthogeriatric/ Physiotherapy referral:
This is also essential to plan rehabilitation programs and longer term placement
strategies as needed. 1
“Vitruvian Man”, pen and ink, Leonardo da Vinci 1492, Gallerie dell’Accademia, Venice,
Italy
Appendix 1
Radiological Classification of NOF fractures
There are 2 classifications: Anatomical and Garden’s
Anatomical Classification
Above, named fractures about the hip.
Left, Classification of hip fractures.
Fractures in the blue area are intracapsular
and those in the red and orange areas are
extracapsular, (BMJ 1 July 2006)
Garden’s Classification
● Garden Type I Incomplete fracture. Lower cortex intact.
● Garden Type II Complete fracture, No angulation or displacement.
● Garden Type III Complete fracture, Rotation and angulation.
● Garden Type IV Displaced fracture.
Garden I Garden I I Garden III Garden IV
Appendix 2
A left pertrochanteric fractured neck of femur in a 77 yr old female.
References
1. Chilov MV, Cameron ID, March LM, Evidence based guidelines for fixing broken
hips, MJA 2003, 179:489-493.
2. McRae R, Practical Fracture Treatment, 3rd
ed 1994, p.260-67.
3. Pitfalls in Orthopedic Radiography Interpretation. Michelle Lin, MD FAAEM Assistant
Clinical Professor of Medicine, UC San Francisco San Francisco General Hospital
Emergency Services 2008.
4. Fergusun D.G, Fodden D.I Accident and Emergency Medicine, Churchill Livingston,
1993
5. From: www.imagingpathways.health.wa.gov.au
6. Images in Clinical Medicine: Occult Hip Fracture. NEJM 359; 26, December 25, 2008
7. Mak JCS, Cameron I.D and March L.M. Evidence-based guidelines for the
management of hip fractures in older persons: an update. MJA 2010; 192: 37–41
Further reading:
“On Beauty, A History of a Western Idea”, edited Umberto Ecco, Seeker and Warburg,
London 2004
Dr J Hayes
Dr S.Pincus, Staff Specialist RMH.
Dr J.Briedis/ Mr. R. Hau
Reviewed 30une 2011.