Introduction
- Fractures occur when the forces acting on a bone exceed its ultimate strength.
- The type of fracture occurring is dependent on the magnitude, rate and direction of the force applied to it, and also the shape, size and structure of the bone involved.
- Separation of the fracture fragments, and therefore the degree of instability, is dependent on the severity of the fracture and any restraining forces from surrounding tissues and their attachments.
- Signs: vary according to site, type, degree of instability, severity of fracture, whether 'open' or 'closed'.
- Treatment: coaptation, external or internal fixation may be necessary – dependent upon site, type, severity of fracture Fracture: internal fixation Fracture: external fixation.
- Prognosis: dependent upon site, type, severity, method of repair,age and co-morbidities.
Presenting signs
- Functional compromise.
General
- History of trauma or suspected trauma Trauma: overview, however minimal or apparently non-traumatic can occur in pathological or fatigue fractures.
- Pain.
- Swelling.
Specific
- Dependent upon site.
- Instability.
- Crepitus – dependent upon distraction of fracture fragments (ends).
- Signs of predisposing condition.
Acute presentation
- Shock Shock.
- Collapse.
- Bleeding ± wounds.
Age predisposition
Physeal
- Young animal <12 months (skeletally immature).
Pathological
- More commonly, but not exclusively middle-aged and older.
Cost considerations
- Internal fixation Fracture: internal fixation.
- External skeletal fixation Fracture fixation: external skeltal fixator.
- Coaptation Fracture fixation: casts.
- Conservative.
Special risks
- The more severe the fracture, the greater the causal forces (usually), and the associated damage to surrounding tissues and other systems.
- Forelimb fractures more likely to have associated thoracic trauma Thorax: trauma.
Pathogenesis
Etiology
- Direct trauma, eg road traffic accident (most common), gun shot.
- Compression, eg fall from height.
- Shearing forces, eg trapped limb.