Chapter 27. Bone and joint injuries
Bone and joint injuries range from the relatively trivial to the life-threatening. The <C>ABC system must be followed. Only when life-threatening injuries have been excluded or treated should limb injuries be assessed.
Mechanism of injury
Fractures
Fractures may be classified in several ways. Injuries may be:
• Closed (simple), if the skin and soft tissues overlying the injury are intact, or
• Open (compound) if bacteria could have entered the wound through damaged skin.
When fractures are treated, wherever possible the normal anatomical alignment should be re-established. This reduces pain and bleeding and helps to prevent damage to adjacent structures. It is perfectly acceptable to reduce a bony fragment back into a wound in order to achieve this.
Fracture anatomy
After a bone has been fractured, the fragments may remain in their normal anatomical relationship to one another (undisplaced) or their relative positions may change (displaced).
 |
| Figure 27.1. |
| A classification of fractures. |
Fractures in children
Even although fracture patterns may differ in children, potential injuries should be assessed and managed in the same way as adults.
Dislocations
Dislocations may occur when similar forces are placed on joints, but the soft tissue structures fail before the surrounding bone fractures.
There are some injuries where fracture and dislocation occur at the same time; e.g. posterior dislocation of the hip with a fracture of the posterior lip of the acetabulum (hip socket). In this case, the acetabulum is fractured by the femur as it passes posteriorly, striking the lip.
General examination
The majority of fractures and dislocations are not immediately life-threatening, but exceptions include fractures of the pelvis, multiple closed fractures or compound fractures of long bones, where serious haemorrhage may occur.
Fractures of the skull and face may lead to airway obstruction or be associated with life-threatening neurological injuries. Fractures may co-exist with injuries to the vital thoracic or abdominal organs.
Limb-threatening injuries are much more likely. Many fractures and dislocations can lead to lifelong disability and thus are very important for the individual patient.
The multiply injured patient may require immediate transfer to hospital without full assessment or treatment of such injuries.
Examination of bones and joint must be systematic if injuries are to be identified (see box below).
Look – The part should be inspected for swelling, deformity and overlying wounds. Are there any pre-existing scars? The joint should be compared with the normal side
Feel – Is the injured part painful and if so, where? Is there any protective muscle spasm? Are the pulses distal to the injury intact?
Move – Can the patient move the injured part?
If there is a fracture then the sensation of grating of the bone ends may be experienced (‘crepitus’). This is extremely painful for the patient and deliberate attempts to elicit crepitus should be avoided.
Assess the limb for vascular injury. The palpation of a distal pulse alone is not sufficient. It is important to assess capillary refill in order to assess tissue perfusion.
The nail bed is compressed for 5 seconds. The pressure is released and the time taken for the return of the normal pink colour is measured. If this is greater than 2 seconds, then tissue perfusion is abnormal. The capillary refill test is best performed in good light and a warm environment.
A neurological assessment of sensation and muscle power should be made in order to determine whether there is a possibility of any nerve damage.
General treatment considerations
All patients who have sustained a long-bone injury should be given oxygen via a Hudson mask with a non-rebreathe valve and a reservoir bag at a rate of 15 L/min.
Analgesia
Entonox is excellent for fractures and dislocations sustained as sports injuries. Intravenous opiate analgesia will be required for significant fractures.
Compound fractures and serious wounds
Infection of a fracture is a disaster for the patient. Osteomyelitis can be controlled, but rarely cured. Good wound care starting at the scene of an accident will help reduce the incidence of this complication.
The fracture must be stabilised to avoid further damage to the soft tissues. Some form of immobilisation or splinting is required. Traction splinting will reduce blood loss, but must not be applied excessively if traction injuries to the nerves are to be avoided.
The wound should be covered in a sterile dressing, soaked in 0.9% saline or aqueous iodine solution. Life-threatening bleeding should be controlled by direct pressure.
Splinting a fracture or dislocation to prevent movement of the injured part is one of the best and simplest forms of pain relief
Simple splintage
Simple splintage of the lower limb may be achieved by securely fastening the injured part to the opposite uninjured leg using triangular bandages or a purpose-built splint.
The limb may be placed in a box splint which should be well padded and should be of the appropriate size for the injured limb.
Vacuum splints are even more effective.
Immobilise the joints above and below the fracture
Traction splintage
Traction splintage is generally employed for femoral shaft fractures. Modern traction splints work on the principle of traction at the ankle and countertraction via a ring at the ischial tuberosity, except for the Sager® splint (a padded T-bar that fits between the legs) which exerts countertraction on the symphysis pubis.
The principle is to reduce the fracture and overcome the deforming force of the surrounding muscles which are in spasm. The restoration of the normal length and shape of the limb also has the advantage of reducing blood loss by up to 20–30%.
Splints that apply traction to one (e.g. the Hare®, Donway® or Trac-Ill® splints) or both lower limbs (e.g. the Sager® splint) are effective.
Adequate splintage of a fractured limb will result in:
• Pain relief
• Reduction of blood loss
• Prevention of further soft tissue damage
• A reduced incidence of fat embolism.
Bone and joint injuries in specific regions
Skull, facial skeleton and cervical spine
Patients who have sustained a fracture to the skull or facial bones have sustained a serious head injury. The airway may be compromised, either directly owing to instability of the facial skeleton (e.g. an unstable fracture of the mandible) or owing to secondary factors such as swelling, bleeding or loss of consciousness. All patients with a head injury should be assessed for injury to the cervical spine.
There is a 5% chance of significant cervical spine injury in the unconscious patient
The airway must take priority, but all reasonable precautions to prevent cervical spine movement must be taken. Neck collars which are combined with immobilisation on a spinal board effect the most secure immobilisation when properly applied.
Pressure necrosis of the skin and soft tissues can be caused by even short periods on a spinal board.
Scoop stretchers can be used when transferring patients from the floor to a stretcher or bed.
The patient’s clothing must be checked for sharp or lumpy objects such as coins or wallets as these will quickly lead to the development of pressure sores in the immobilised patient. This is particularly important in the unconscious patient.
The upper limb
Fractured clavicle
Cause
Fall on the outstretched hand (FOOSH), when the forces transmitted up the upper limb may indirectly result in a fracture, or from a direct blow.
Signs and symptoms
Pain occurs at the site of the fracture whenever the upper limb is moved. The patient often supports the injured arm at the elbow in an attempt to reduce movement of the limb. There is usually swelling at the site of the fracture, which typically occurs at the junction of the outer (lateral) third and inner (medial) two-thirds of the bone.
Treatment
The upper limb should be immobilised in a broad arm sling. A collar and cuff should not be used, as this will act to separate the bony ends of the fracture due to the weight of the arm.
Potential problems
This is usually a straightforward injury to treat. The sling will often control the pain as it prevents movement at the fracture site. As with all limb injuries, there is a chance of damage to important vascular and neurological structures close to the fracture site. The subclavian artery and vein are in close proximity to the clavicle and although injury to them is rare, it can be serious. Similarly, the nerves that supply the upper limb may be injured, particularly when the fracture has been caused by direct rather than indirect force. Direct injury to this region may also result in chest injury and the assessment must not be confined to the clavicle.
Always check distal neurovascular function
Fractured scapula
Cause
Usually due to a direct blow, most commonly after a fall from a motorcycle, from a blunt weapon during an assault or accidentally during a sporting event with a stick or bat (e.g., a hockey stick). The scapula is surrounded by muscle and this is an unusual injury, considerable force being required.
Signs and symptoms
Pain occurs over the site of the fracture and may be made worse with movement of the upper limb.
Treatment
Immobilisation of the upper limb in a broad arm sling will reduce the discomfort.
Potential problems
There may be associated injuries to the thoracic cage and ribs and these need careful examination.
Dislocation of the sternoclavicular joint
Cause
Fall on the outstretched hand (FOOSH) or by direct injury to the anterior aspect of the shoulder, levering the medial end of the clavicle away from its usual articulation with the manubrium of the sternum.
Signs and symptoms
There is pain localised at the medial end of the clavicle, made worse by movement of the upper limb. There may be swelling and deformity over the sternoclavicular joint.
Treatment
The vast majority of these injuries are subluxations or partial dislocations. They are best treated in a broad arm sling.
Potential problems
Occasionally there is severe displacement. If the medial end of the clavicle has been dislocated posteriorly, then the major vessels are in danger of injury. The patient should be examined for signs of chest injury and shock. If there is evidence of shock, they should be considered to have a severe, potentially life-threatening injury and evacuated to hospital immediately. Intravenous access can be achieved in transit and any delay in reaching hospital should be avoided. Occasionally posterior dislocation of the sternoclavicular joint may produce airway obstruction: the clavicle should be pulled forwards, as a matter of urgency.
Dislocation of the acromioclavicular joint
Cause
Usually a fall onto the point of the shoulder. It is a common injury in rugby football. This injury results from partial or complete disruption of ligaments between the clavicle and the acromion and in severe cases also the ligaments between the clavicle and the underlying coracoid process of the scapula.
Signs and symptoms
Pain at the lateral end of the clavicle, made worse by attempting to carry any weight with the affected arm. There will be a variable amount of local swelling and usually a step is visible between the lateral end of the clavicle and the acromion (this is the expanded anterolateral process of the scapula which forms a bony roof over the shoulder joint and muscles and normally articulates with the clavicle).
Treatment
The upper limb should be immobilised in a broad arm sling.
Potential problems
The mechanism of injury should lead to a high level of suspicion of associated injuries to the cervical spine and nerves in the brachial plexus.
Anterior dislocation of the shoulder
Cause
Usually caused by forced external rotation of the glenohumeral joint (the joint between the humerus and the glenoid process of the scapula). Typically, this results from a fall or a mistimed rugby tackle. If the shoulder has previously been dislocated, then less force is required to produce a recurrent injury.
Symptoms and signs
The patient will be supporting the forearm with the elbow flexed. The shoulder will look abnormal (square contour) compared with the other side, with a loss of the usual rounded contour of the upper arm. The lateral edge of the scapula may well appear prominent. It is important to assess the sensory portion of the axillary nerve which provides sensation to the ‘regimental badge’ area of skin on the lateral aspect of the proximal arm.
Treatment
Treatment should be directed at immobilising the upper limb during transfer to hospital for relocation of the joint. An acceptable method is to allow the patient to sit upright and support the arm, perhaps resting it on a pillow. The sooner the joint is relocated the better.
Potential problems
The longer the joint is dislocated, the more permanent damage is done to the articular surface of the bone and to the soft tissues. All the nerves of the upper limb can be at risk. Damage to the major blood vessels may occur and proper examination and reexamination of the distal limb circulation is essential. Severe fractures and fracture-dislocations of the surgical neck of the humerus may mimic simple anterior dislocation.
Posterior dislocation of the shoulder
Cause
Often a fall on the outstretched hand with the arm internally rotated or a direct blow to the anterior aspect of the shoulder. An electric shock, epileptic fit or chronic muscle spasticity such as is seen in cerebral palsy can also cause posterior dislocation.
Symptoms and signs
These are similar to those of anterior dislocation, with pain, swelling and local deformity.
Treatment
The arm should be immobilised and the patient transported to hospital.
Potential problems
The nerves in the brachial plexus are particularly susceptible to damage due to pressure from the humeral head. Recognition and early relocation are essential. The X-ray changes are very subtle and this injury can be easily missed in hospital.
Inferior dislocation of the shoulder
Cause
Inferior dislocation is extremely rare but can follow a violent convulsion or an electric shock.
Symptoms and signs
The arm is held extended above the head and the injury is extremely painful. The condition is often bilateral.
Treatment
Analgesia and support during the transfer to the hospital are all that is required.
Potential problems
Fitting the patient onto the stretcher may be difficult.
Fracture of the proximal humerus
Cause
Usually either a fall onto the outstretched hand (FOOSH) or a direct fall onto the upper arm, particularly in elderly patients and those with osteoporosis. The fracture can occur in younger patients following direct violence.
Symptoms and signs
There is pain at the upper end of the arm. The patient will usually be supporting the arm at the elbow with the other hand. There may be obvious deformity. Swelling is almost immediate, but the severe bruising which accompanies this injury may not be apparent for several days and can track distally down the lateral aspect of the arm.
Treatment
The arm is supported in a broad arm sling initially. Once the diagnosis has been confirmed in the accident and emergency department, the sling should be changed to a ‘collar and cuff.’ This allows the weight of the arm to apply traction to the fracture and tends to reduce the fractured bone into its normal anatomical position.
Potential problems
As with all fractures, the surrounding nerves and blood vessels can be injured directly at the time of the fracture.
Fracture of the shaft of the humerus
Cause
The shaft of the humerus may be fractured through direct injury such as a fall onto the arm or a blow from a blunt weapon. Indirect force can cause these fractures, although the fracture pattern may be different.
Symptoms and signs
The arm is painful and may be supported at the elbow by the other hand. There may be obvious angular deformity, but rotational malalignment is not always obvious. There may be significant swelling and bruising. It is essential to examine the distal portions of the limb to exclude vascular and neurological injury.
Treatment
The arm should be supported in a broad arm sling.
Potential problems
The radial nerve runs in a groove, closely applied to the humeral shaft posteriorly. It may be damaged directly or secondarily due to swelling (compartment syndrome). Loss of radial nerve function may lead to weakness of the muscles that extend the wrist and as a result the patient will demonstrate ‘wrist drop’ (inability to extend the wrist). The arterial blood supply to the upper limb is via just one vessel at this point, the brachial artery. This artery may suffer direct injury or may be constricted owing to a compartment syndrome.
Supracondylar fracture of the humerus
Cause
Supracondylar fractures of the distal portion of the humerus just proximal to the elbow joint are common in childhood. They are typically caused by a fall onto the outstretched hand. The fractures can range from an undisplaced crack to a completely displaced injury with vascular and neurological damage.
Symptoms and signs
There is pain at the elbow after a fall. The child will support the elbow with the other hand. There may be obvious swelling and deformity and serious interference with the blood supply to the distal part of the limb.
Treatment
Buy Membership for Emergency Medicine Category to continue reading. Learn more here
