Definition

A fractured neck of femur (FNOF) involves a fracture occurring in the location of the femoral neck (the weakest area of the femur). FNOF is primarily an injury of older people but may also occur in younger people with a history of violent trauma. 

They are very common, with an incidence of 75,000 in the UK, set to rise to 100,000 by 2020. There is huge morbidity and mortality associated with this injury, with a 10% one-month mortality rising to 33% at one year. This is mostly due to patients being elderly and having multiple co-morbidities. Understandably this has large cost implications, currently costing the NHS up to 2 million pounds a year.

The fractured neck of femur best practice tariff was introduced due to variable care provision across the country. Sub-optimal care leads to longer hospital stays and poorer outcomes for patients. The best practice tariff aims to standardise treatment, to ensure best possible patient outcomes.


Causes

Osteoporosis / osteopenia

Trauma – often falls in the elderly

Pathological fractures –   primary bone tumours or metastatic deposits leading to fracture


Diagnosis 

Common findings in the history

Fall (however may be atraumatic, particularly in pathological fractures)

Pain:

  • May be felt in the hip, groin and knee
  • May be an exacerbation of pre-existing pain from another cause (e.g osteoarthritis)

Reduced mobility/sudden inability to weight bare

 

Examination findings

  • Classically the affected leg is shortened, ABducted and externally rotated
  • Exacerbation of pain on palpation of the greater trochanter
  • Pain is exacerbated by rotation of the hip

If you have a suspicion that the hip is fractured you should avoid vigorous examination as there is a risk of displacing the fracture.

 

Right extracapsular intertrochanteric fractured neck of femur

Investigations

X-rays:

  • AP Pelvis
  • Lateral hip
  • Usually sufficient to make the diagnosis

 

If you have a high clinical suspicion and no X-ray diagnosis:

  • Gold standard is an MRI of the hip joint
  • This is often not quickly available, so CT is more commonly used in practice

Don’t forget that these patients often die from their co-morbidities.

Investigate and treat these co-morbidities (e.g. anaemia, AF, infections etc).


Management

Pre-op

Regardless of the specific type of fracture, the initial management steps are the same.

  • Adequate analgesia (if available make use of regional anaesthesia techniques such as nerve blocks)
  • IV access
  • Bloods – group and save, FBC, U&E, LFTs, bone profile, coagulation
  • Correct any blood abnormalities – anaemia, dehydration, coagulopathy
  • Diagnose and treat co-morbidities – e.g. heart failure, pneumonia etc
  • Document pre-morbid state – e.g. could they mobilise independently prior to injury?
  • Screen for cognitive impairment – part of the best practice tariff – prognostically significant

Patients should be under joint care with a geriatrician.

 

Surgery

Surgery needs to take place within 36 hours of admission.

  • Fractures are classified as extracapsular or intracapsular.
  • This is an important distinction because the management and risk of complications differ.
  • The main blood supply of the femoral head traverses under the capsule and along the femoral neck. As a result, the possibility of developing avascular necrosis of the femoral head is much more likely in intracapsular fractures (even more so in those involving displacement).

 

Intracapsular

Grouped into four different types according to Garden classification

  • Group I & II refer to undisplaced intracapsular fractures
  • Group III & IV refer to displaced intracapsular fractures

 

Undisplaced intracapsular fractures (I & II)

  • Often impacted and likely to unite with bed rest
  • However, prolonged bed rest is associated with significant complications (thromboembolic disease/pneumonia etc)
  • As a result, the aim is to stabilise these fractures, to prevent displacement, usually with screws through the neck into the head of the femur

 

Displaced intracapsular fractures (III & IV)

  • High risk of avascular necrosis
  • Unlikely to unite
  • Hemi-arthroplasty is often recommended in the elderly, due to the risk of subsequent necrosis of the femoral head
  • Patients with pre-existing joint disease who are still fairly active and have a reasonable life expectancy should have a total hip replacement
  • In younger patients reduction and screws may be used, in an effort to preserve the patients own femoral head for as long as possible

 

Extracapsular

  • As the name suggests, these fractures do not involve the capsule
  • As a result, the risk of avascular necrosis is much less
  • They can be further divided into displaced and nondisplaced, however, management is largely the same
  • In reality, undisplaced extracapsular fractures could quite easily be managed conservatively
  • However given the previously mentioned urgency to mobilise early, these fractures receive operative intervention

 

The most common surgical method of management involves a dynamic hip screw:

  • In this procedure, a screw is placed through the femur and into the femoral head
  • A plate is then attached along the femoral shaft which attaches to the screw
  • These fractures tend to collapse, so the plate allows the screw to slide along it
  • Collapse, despite sounding less than ideal, actually leads to a much more stable structure

 

Dynamic hip screw

 

 

Post-op

If no contraindications present, day one mobilisation will be attempted.

Thromboprophylaxis – e.g. low molecular weight heparin

Daily physiotherapy

Ongoing MDT approach with orthogeriatric input.

 

Medications review:

  • Review bone protection – Vitamin D / Calcium supplements and Bisphosphonates
  • If the fracture was due to a fall,  review medications for iatrogenic causes

Complications

Infection

Bleeding

Increased risk of thromboembolic events – deep vein thrombosis / pulmonary embolism

Avascular necrosis of the femoral head


References

Hip Fractures: The management of hip fractures in adults. Nice clinical guidance June 2011.

Surgical Talk. Revision in Surgery. 2005. Andrew Goldberg, Gerald Stansby


 

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