Fractured Neck of Femur

Contributors

  • Andrew Roberton

Fractured Neck of Femur

Introduction

Hip fracture is the most common serious injury in the elderly population and the most common reason for being admitted to an orthopaedic ward.  It is a major cause of mortality and morbidity.

  • Approximately 75,000 hip fractures treated each year in the UK.
  • More common in women.
  • One-year mortality after hip fracture is estimated to be as high as 30%.
  • It has been estimated that hip fracture costs the NHS £1.4 billion per year.
  • It is an example of a fragility fracture (most often secondary to osteoporosis) – accounting for as many as 87% of all fragility fractures.
  • Neck of femur fractures are intracapsular hip fractures.

Clinical Features

History

  • Usually a fall accompanied by pain.
  • Be aware that injuring force can be trivial.
  • In a younger patient, considerable force (e.g. motor vehicle collision) is usually involved.

Examination

  • External rotation and shortening of affected limb.
  • Adduction may also accompany these findings.
  • Important to look for other injuries.

X-ray

  • Anteroposterior (AP) and lateral views of hip should be ordered and are able to demonstrate most fractures.
  • Pay particular attention to Shenton’s lines if not an obvious fracture.
    • 2 important findings from the x-rays:

             1.  Fracture/No fracture?

             2.  Displaced/Non-displaced?

      Classification

      • “Garden’s” classification (not commonly used in clinical practice) classifies femoral neck fractures from stage 1 to 4.

       

      Treatment

      Initial treatment:

      • Assess vital signs and treat appropriately.  Patients may well have been on the ground for some time and be hypothermic and dehydrated.
      • Relieve pain with analgesia (morphine).
      • Prepare for theatre including cross-matching blood.  Patients can lose as much as 2 litres of blood as a result of a hip fracture

      Definitive treatment:

      Treatment is almost always surgery.  Conservative management is rarely considered. It is important to consider that the majority of neck of femur fractures occur in the elderly population.  The consequence of not operating would mean extended bed rest.  The resulting immobility can have disastrous consequences such as thromboembolism and development of pneumonia.  Therefore speed is always of the essence in treating neck of femur fractures.

      Surgical options include:

      1.   Internal fixation: for undisplaced fractures.  This includes:

      • Dynamic hip screw (DHS)
      • Cannulated screws

      2.   Arthroplasty: for displaced fractures.  This includes:

      • Total hip arthroplasty
      • Hemiarthroplasty

        The important issue to consider in deciding the surgical option is the risk of developing avascular necrosis.  See picture "Blood supply to femoral neck" below.  Briefly, there are 3 main supplies to the femoral neck:

        1. Intramedullary vessels

        2. Circumflex arteries branching into retinacular arteries

        3. Artery to head of femur within ligamentum teres - provides only a very small supply of blood

         

        In displaced fractures, there is greater likelihood of disruption to the intramedullary and circumflex/retinacular vessels supplying the femoral head.  Therefore arthroplasty is best option in most displaced neck of femur fractures.

        Also important to consider:

          - Venous thromboembolism prophylaxis

          - Early mobilisation post-surgery (same day or day after surgery)

          - Multidisciplinary team approach to rehabilitation

          - Prevention of further hip fractures through:

              >Preventing falls

              >Treatment of osteoporosis

            Blood supply to femoral neck

            Complications

            General complications

            • Thromboembolism
            • Pneumonia
            • Bed sores

             

            Specific complications

            • Avascular necrosis - occurs in approximately 30% of displaced fractures and 10% of non-displaced.
            • Non-union - as many as 1/3 of neck of femur fractures may not unite
            • Malunion - where union occurs in a faulty position. E.g. union with angulation, rotation or shortening.  Treating underlying osteoporosis may help prevent this.
            • Osteoarthritis

            Further reading

            Solomon L, Warwick DJ, Nayagam S. (2005) Injuries of the Hip and Femur. In: Solomon L, Warwick DJ, Nayagam S. (Ed.) Apley's Concise System of Orthopaedics and Fractures. 3rd ed. (pp362-365) London: Hodder Arnold.

            Collier J, Longmore M, Turmezei T, Mafi AR. (2010) Orthopaedics and Trauma. In: Collier J, Longmore M, Turmezei T, Mafi AR (Ed.) Mini Oxford Handbook of Clinical Specialties. 8th ed. (pp 752-753) Oxford: Oxford University Press.

            http://orthopedics.about.com/cs/hipsurgery/a/brokenhip_2.htm

            http://emedicine.medscape.com/article/825363-overview

            http://www.sign.ac.uk/pdf/sign111.pdf

            http://www.nhfd.co.uk/

            http://www.patient.co.uk/health/Hip-Fracture.htm