This is a general introduction to fractures.  The aim is to familiarise yourself with the process of identifying fractures, both clinically and radiologically, and understand the different management options available.

What is a Fracture?

A fracture is defined as a disruption in bone continuity.  The degree of disruption can vary from a crack in the cortex to multifragmentation.  Fractures are often associated with local tissue trauma.  Again, the severity can vary; from mild oedema to vascular compromise.   Fractures are common, and most people will sustain one across a lifetime.  There is a typical 3 peak incidence, childhood, young adulthood and in the elderly.

How do fractures occur?

Bone is a relatively brittle material; it maintains sufficient strength to withstand regular day to day activities.  Fractures are a result of trauma to bone, when applied force exceeds bone strength.  The degree of force typically relates to the outcome, greater force results in greater severity of injury, conversely less severe injuries result from lower applied force.  When fractures occur at abnormally low impact they are termed ‘pathological’.

Classification of Fractures

> Open and Closed

  • Open (Compound)- Skin surface or body cavities are breached as a result of the fracture.  They are associated with greater local tissue trauma and risk of bone infection.
  • Closed (Simple)-No breach of skin or body cavities.  Variable degrees of local tissue trauma.

 

> Complete and Incomplete

  • Complete- Two or more bone fragments
  • Incomplete-  Periosteal continuity is maintained

 

Fracture Patttern

The mechanism of injury often determines the fracture pattern:

 

> Sudden trauma

  • Direct trauma(at fracture site) typically produces a complete fracture in adults with an oblique / transverse pattern.  In peadiatics this can sometimes produce an incomplete buckle (Greenstick) fracture. 
  • Indirect (away from fracture site), can produce a spiral pattern. 

 

> Repetitive stress

Causes mechanical strain and fatigue, a stress fracture can result, categorised as an incomplete fracture.  

 

See image below for examples of different fracture patterns.

Fracture Patterns

Identifying Fractures- Clinically

    • History

    Almost always a good history of the injury (either elicited from the patient, parent or witness) will indicate if a fracture is likely. 

    It will be common for the patient to report an inability to use the injured limb.

    Ensure you take details of the trauma, fall, and landing as relevant.

    Think about the mechanism of injury and force distribution, fractures may not always be at the site of impact.

    Associated numbness, weakness and bleeding are important- You need to determine if the affected limb is neurovascularly intact.

    Enquire about previous injuries.

     

    • Examination

    Don't focus your examination entirely on the suspected fracture. 

    Examine the person as a whole for any complications and associated injury. Don't overlook ABC.

    Always compare limbs- that's why we have two.

     

    LOOK:

    General Inspection

    1. Shock/ Heamorrhage/ Associated damage related to CNS and vicera

     

    Local Inspection

    1. Skin- Colour change/ Pallor/ bruising/ wounds/ scars
    2. Shape- Swelling/ Obvious deformity
    3. Position- Joints (above and below)/ bones
    4. Is there any shortening of the limb?

     

    FEEL

    1. Skin- Temperature/ moist
    2. Pulse (To assess vascular involvement)
    3. Peripheral neurological status
    4. Tenderness- Often severe and easily located

     

    MOVE ( ! If appropriate)

    1. Active
    2. Passive

     

    NB: When examining for spinal fractures, the patient must be log-rolled and a full peripheral nervous system examination performed.

     

    Identifying Fractures- Radiologically

    • Plain Film Radiograph (X-Ray)

    X-Rays of a suspected fracture are mandatory and usually diagnositic.  Medical practioners have a low threshold for requesting x-ray if the history or clincal exam is sugestive of bone injury.

    Always remember the rule of two:

    1. Two views. At 90 degrees, usually anterior-posterior and lateral. Displacement of fractures can only be interpreted accurately when seen in two planes. 
    2. Two joints. The joints above and below, this allows assessment of angulation and rotation. 
    3. Two occasions. Some fractures are not easily visible immediately after trauma.  For example scaphoid fracture is best viewed 10 days post injury by x-ray where bone reabsorption makes the fracture more evident. 
    4. Two limbs. If required for comparison.

     

    Special views of certain injuries are preferred.  These include Scaphoid views and Mortis view at the ankle.

     

    • Computed Tomography (CT)

    Usually required when the fracture is multifragmetory, it allows assessment of the fracture pattern.  CT is most useful in planning surgical management of complex fractures and identifying articular involvement.

     

    • Magnetic Resonance Imaging (MRI)

    Not frequent in the diagnosis of fractures, but commonly used for assessing for Avascular Necrosis (AVN) and soft tissue injury.

     

    • Radionuclide Scanning

    This imaging identifies areas of new bone formation and is most helpful in diagnosing stress fractures.

     

    Bone Healing

    Fracture repair can be roughly divided into healing with or without callus formation.  Repair with callus will occur where there is a degree of movement at the fracture site, where there is no movement direct repair takes place. 

     

    • Healing with callus

    5 Stages:

    1. 1. Injury and tissue death- Cellular invasion at the fracture site causes vascular constriction and haematoma formation.  The fracture surface with damaged tissue becomes deprived and dies. 
    2. 2. Acute inflammation and granulation-  <8hours.  Within the bone, cellular proliferation occurs, granulation tissue is formed and capillaries begin to grow into the area. 
    3. 3. Callus formation- Proliferating cells develop into chondroblasts and oesteoblasts. Fracture callus forms as a mixture of immature bone and hyaline cartilage bridging the fragments of bone and acting as a splint.  This process is stimulated by movement at the fracture site. 
    4. 4. Endochondral ossification- Immature bone is replaced by lamellar bone.  Once completed the bone would have regained the majority of its original strength. 
    5. 5. Remodeling- Continued bone reabsorption and formation at the fracture site occurs over many months returning to its original structure.

     

    • Direct repair

    Where there is no movement stimulating callus formation, bone is laid down directly across the fracture site.  This occurs where rigid fixation is chosen.  Mechanical stability is provided by the implant, and callus is not required as a splint.  Oestoclasts begin to degrade bone debris with oestoblasts follow behind laying down new bone. 

     

     

      When a bone is able to withstand normal stresses it is functionally repaired.  However remodeling will continue after this point, as will restoration of bone density. 

      Complete repair of bone can take considerable time.  The rate is dependent on the type of bone, type of fracture, health of tissue and patient age.  The healing process in children is almost half that of an adult.

       

      Management of Closed Fractures

      Diagnosis is often simple but management options are more complex.  Three principles are used when treating fractures: Reduction, Stabilisation, and Rehabilitation. 

       

      • Reduce

      Due to the force of impact or surrounding muscle groups, the normal alignment of the affected bone may be compromised.  If this is the case and the alignment of the bone is not satisfactory, the position of the fragments will need to be altered in order to maximise bone healing in the correct position.

      Not all fractures result in misalignment, and in these circumstances reduction will not be indicated. Figure 3 demonstrates some examples of deformities that may need to be reduced. 

      Soft tissue swelling post injury can cause difficulty in reduction and for this reason there should be no unnecessary delay.

       

      > Closed reduction:

      If the degree of displacement is minimal, or in most peadiatric fractures, the option of closed reduction is preferred.  This can be with: Repositioning in a regular clinical setting with analgesia or Manipulation Under Anaesthetic (MUA), where the patient is taken to theatre and the fracture is reduced by the surgeon with the assistance of x-ray.

       

      > Open reduction:

      Surgical intervention is required if closed reduction fails, or if initially the degree of displacement is significant.  Open reduction is usually the first stage to internal fixation (Open Reduction and Internal Fixation ORIF)

       

      • Stabilise

      The theory behind stabilising the fracture is to hold the bone fragments in a good position for healing, prevent excessive movement that could hamper fracture union (this may require joint immobilsation proximal and/or distally) and reduce pain.  There is no hard and fast rule for which fracture should be stabilised by which method.  Each fracture is individual and should be managed as such, also taking into account patient factors.

      Stabilisation falls into two broad categories, Conservative and Operative. Methods of fracture stabilisation are discussed respectively.

       

      > Conservative

      1) Casting, usually with Plaster of Paris (POP).  This acts as a splint to maintain the either original or post reduction position.

      2) Traction, a calculated force is applied to the long axis of the bone, causing opposing fragments to separate and align in the correct position.  This is enabled with specialised equipment using weights to generate the traction force.  Traction can be applied in one of two methods: Skin traction where the device is applied superficially, around the skin; or secondly where per cutaneous pins, are directly attached to the the distal bone fragment.

       

      >Operative

      Usually termed Open Reduction and Internal Fixation (ORIF)

      1) Krishner Wires, also known as K-Wires. Per cutaneous insertion, across the fracture site to maintain alignment.  K wires are only temporary, and can be removed once union is established. Metaphysial fractures, and fractures of short bones (ie metacarpal) are often managed with this type of fixation.

      2) Plates and Screws, usually used in conjunction.  Plates provide mechanical stability as well as ensuring maintainance of alignment.  There is many design of plate, tailored for specific regions and fracture pattern.  Screws can also be used independently, across a fracture site.

      3) Intramedullary nailing, most commonly used in long bones.  A nail is passed along the long axis of the bone, within the cortex, acting as an internal splint. 

      4) External Fixation, provides stability away from the fracture site, without interruption of soft tissue structures.  Per cutaneous screws are applied to the proximal and distal fragments of the bone, and attached to a external frame.

      5) Hemi and Total Arthroplasty, partial and total joint replacement.  This is not a common management of fracture but can be considered in certain intra-articular circumstances and at the femoral neck where there is a risk of Avascular Necrosis (AVN).

       

         

        • Rehabilitate

        Once the fracture has been stabilised and the healing process is underway, attention is diverted to functional improvement and a return to normality.  Early mobilisation is often encouraged, providing stability is not compromised.  This aids in avoiding joint stiffness, loss of muscle power and oedema.

        Rehabilitation is tailored according to both the injury and patient circumstance. Multidisciplinary input is used in varying degrees, this can including the expertise of Physiotherapists and Occupational Therapists if necessary. 

        Management of Open Fractures

        Open fractures are a surgical emergency.

         

        • All wounds communicating (or thought to be communicating) with the fracture are considered contaminated regardless of appearance and size.  Once the patients condition is stable, initial fracture management is to ensure no infection is established.  Appropriate IV antibiotics are prescribed as soon as practically possible.  British Orthopaedic Association guidelines recommend- Co-Amoxiclav-1.2g or Cefuroxime-1.5g 8 hourly until wound debridement. (IF Penicillin allergic Clindamycin-600mg 6 hourly) ideally within 3 hours of injury.  

         

        • Repeated neurovascular assessment is essential, particularly following any necessary immediate  reduction or stabilisation.  Vascular compromise requires immediate surgery in order to restore circulation; Nerve damaged is recommended left alone.

         

        • Combined Orthopaedic and Plastic surgical intervention is optimal in regard to both soft tissue and bone injuries.  

         

        • Early surgical intervention with wound debridement is often required.  This procedure ensures the wound is cleaned and devitalised tissue is excised. 

         

        • Long term fracture stabilisation is only now considered, followed by rehabilitation.

         

        Complications Of Fractures

        Complications that can potentially result from a fracture are divided into local and general effects, but also according to their onset: Early (within hours), Intermediate (days- weeks), Late (weeks-months).

        References

        British Orthopaedic Association www.boa.co.uk

        Crash Course: Rheumatology and Orthopaedics; Annabel Coote, Paul Haslam;  2nd edition; Mosby; 2004.

        Consise System of Orthopaedics and Fractures; Graham Apley, Louis Solomon; 2nd edition; Butterworth Heinemann; 1994.

        Essential Orthopaedics and Trauma; David Dandy, Dennis Edwards; 4th edition; Churchill Livingstone; 1999.

        Wheeless' Textbook of Orthopaedics; www.wheelessonline.com

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