Age‐Dependent Fracture Characteristics of Rigid and Compliant Surface Impacts on the Infant Skull—A Porcine Model*^,†

Abstract

This study documents skull fracture characteristics on infant porcine specimens under known impact conditions with respect to age and interface. A single impact causing fracture was conducted on the skull of porcine specimens aged 2-28 days (n = 76). Paired rigid and compliant impacts at the same energy were conducted at each specimen age. Impact force, impact duration, and fracture length were recorded. Energy required to initiate skull fracture increased with specimen age. For a given energy, impact of the skull with a compliant interface caused more fracture damage than with a rigid interface for specimens aged under 17 days, but less damage for specimens aged 24-28 days. The documentation of energy required to cause fracture and resulting fracture propagation with respect to impact interface and age may be of critical importance in forensic investigations of infant skull trauma.

How hard is hard enough? An investigation of the force associated with lateral blunt force trauma to the porcine cranium

“…Porcine bone is believed to be a suitable human bone substitute in fracture research and has been used as a model in many forensic studies [3,[15][16][17]34,35]. Isolated porcine heads were used in the current study.…”

“…Those studies which have investigated lateral impact biomechanics have utilised a variety of different methodologies including: static compression tests [11] (as cited in [7]), drop tests [3,[12][13][14][15][16][17], free fall tests [18][19][20], impacts with a pneumatic/ hydraulic piston [21,22], gas gun tests [23,24] and pendulum set ups [25]. Specimens utilised in these tests have also varied greatly, comprising of intact human cadavers, intact cadaver heads, dry human skulls and porcine specimens.…”

The importance of nonlinear tissue modelling in finite element simulations of infant head impacts

“…Further, both the experimental and the simulated impact surface area suggest an overall increase with age, which is consistent with animal drop tests using infant porcine specimens (Baumer et al. 2010). …”

“…This observation is consistent with experimental findings using infant porcine skull, where fractures initiated at bone–suture interfaces (Baumer et al. 2010). While in the studies using human PMHS by Weber (1984, 1985) only the fracture patterns were depicted and no discussion on the initiation of fractures was provided.…”

Biomechanical and Remodeling Factors in the Interpretation of Fractures in Juveniles

“…In their experimental study of the fracture process in young pigs aged 2-28 days, Baumer et al [84] explored factors of age as well as surface characteristics of the impacting object. They found that the energy required to initiate a fracture increased with increasing age.…”