Complications
Absent circulation: Absent circulation to the limb is rarely life-threatening. Muscle necrosis can take up to six hours to occur after circulation has been lost. However, the sooner circulation is restored, the less the damage to tissues, and it should be restored as soon as possible. This is usually by reduction of a fracture or dislocation which restores normal anatomy and relieves any distortion of a blood vessel.
Acute compartment syndrome: (ACS) is a condition in which increased pressure within a limited space comprises the circulation and function of the tissues within that space (McCaffrey, 2009). ACS can have significant morbidity if not diagnosed and managed early. The increasing pressure within the compartment can be accommodated up to a critical threshold, after which the microcirculation is unable to meet the metabolic demands of the tissue, resulting in ischemic necrosis.
ACS must be recognized and treated early via fasciotomy to prevent complications such as:
- Neurological deficit
- Ischemic contracture
- Infection
- Crush syndrome
- Amputation
- Death
Making the clinical diagnosis of ACS can be difficult in the pre-hospital setting. Signs and symptoms of ACS include:
- Severe pain out of proportion to the injury
- Pain on passive movement
- Tense swelling
Late signs include:
- Paraesthesia
- Paresis
- Pulseless
According to Elliot & Johnstone (2003) the most reliable findings in making the initial diagnosis of ACS include, severe pain that is out of proportion to the clinical situation, pain activated by passive stretching of the muscles within the affected compartment, sensory abnormality, and motor deficit.
Early diagnosis of ACS can be difficult, and a high index of suspicion is needed.
Management includes appropriate resuscitation, analgesia, the removal of constricting devices and referral to an appropriate emergency department as a matter of urgency. Early referral is necessary for assessment, observation, pressure monitoring and fasciotomy , if indicated.
There is often still a distal pulse present (albeit weak) until quite late in ACS. Weakness and paralysis of the limb are also late signs. A high index of suspicion is based on the injury, pain beyond that expected for that injury and increased pain on passive stretching.
Neurological Injury: any nerve that is anatomically near to an injured area can be damaged by a fracture e.g. a fracture of the fibula neck can damage the common, deep or superficial peroneal nerves, If the deep peroneal nerve is damaged this can lead to weakness in ankle and toe dorsiflexion and to reduced sensation in the 1st/2nd web space. Damage to the superficial peroneal nerve causes weakness of ankle eversion and altered sensation along the lateral dorsum of the foot. It is important to assess the neurological status (motor and sensory) of the limb, especially pre- and post-reduction of a fracture or dislocation.
The risk is of neurological injury is higher if near a dislocated joint.