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.