A skull fracture is a break in one or more of the eight bones that form the cranial portion of the skull, usually occurring as a result of blunt force trauma. If the force of the impact is excessive, the bone may fracture at or near the site of the impact and cause damage to the underlying physical structures contained within the skull such as the membranes, blood vessels, and brain, even in the absence of a fracture.
While an uncomplicated skull fracture can occur without associated physical or neurological damage and is in itself usually not clinically significant, a fracture in healthy bone indicates that a substantial amount of force has been applied and increases the possibility of associated injury. Any significant blow to the head results in a concussion, with or without loss of consciousness.
A fracture in conjunction with an overlying laceration that tears the epidermis and the meninges, or runs through the paranasal sinuses and the middle ear structures, bringing the outside environment into contact with the cranial cavity is called a compound fracture. Compound fractures can either be clean or contaminated.
There are four major types of skull fractures:
Linear fractures are the most common, and usually require no intervention for the fracture itself. Depressed fractures are usually commnuted, with broken portions of bone displaced inward—and may require surgical intervention to repair underlying tissue damage. Diastatic fractures widen the sutures of the skull and usually affect children under three. Basilar fractures are in the bones at the base of the skull.
Gravel et al., conducted a study to develop and validate a clinical decision rule to identify skull fracture in young children with head trauma and no immediate need for head tomography.
They performed a prospective cohort study in 3 tertiary care emergency departments in the province of Quebec. Participants were children less than 2 years old who had a head trauma and were not at high risk of clinically important traumatic brain injury (Glasgow Coma Scale score < 15, altered level of consciousness or palpable skull fracture). The primary outcome was skull fracture. For each participant, the treating physician completed a standardized report form after physical examination and before radiologic evaluation. The decision to order skull radiography was at the physician's discretion. The clinical decision rule was derived using recursive partitioning.
A total of 811 patients (49 with skull fracture) were recruited during the derivation phase. The 2 predictors identified through recursive partitioning were parietal or occipital swelling or hematoma and age less than 2 months. The rule had a sensitivity of 94% (95% confidence interval [CI] 83%-99%) and a specificity of 86% (95% CI 84%-89%) in the derivation phase. During the validation phase, 856 participants (44 with skull fracture) were recruited. The rule had a sensitivity of 89% and a specificity of 87% during this phase.
The clinical decision rule developed in this study identified about 90% of skull fractures among young children with mild head trauma who had no immediate indication for head tomography. Use of the rule would have reduced the number of radiologic evaluations by about 60% 1).