Page 93 - Clinical relevance of current materials for cranial implants

The absorbed energy upon hitting a flat surface was calculated using the following:
Where E is the absorbed energy [in joules], m is the mass [in kilograms], which was assumed to be 2.25 kg, half of the mass of the patient’s head (4.5 kg 21) as it is supported at one side, and v is the speed [in meters per second]. Using these equations, the corresponding speed was calculated at which an impact with a flat and hard surface would cause the maximum tensile stress required for fracture.
AB4 Figure 3: A)The fractured PMMA cranioplasty and B) 3D models created from the computed tomography data
from the shards surrounding the suspected point of failure.
In vivo fractured PMMA cranioplasty
Figure 4: Simplified model of the cranioplasty before fracture.
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