Extension-Type Spinal Fractures on Flat Surfaces: Forensic Autopsy Findings From Two Cases

Extension-distraction injuries of the spine, classified as B3 in the AOSpine Trauma Classification system, are generally attributed to hyperextension mechanisms. However, under specific biomechanical conditions, such injuries may occur even on flat surfaces not typically associated with high-energy trauma. We present two forensic autopsy cases of extension-type vertebral fractures occurring in flat-surface settings. The first case involved a man in his 50s who sustained a thoracic vertebral fracture and cardiac rupture after being compressed dorsally in the prone position by a 1,000-kg brush cutter. The second case involved a man in his 90s with kyphosis who sustained a lumbar extension-type fracture during cardiopulmonary resuscitation after collapsing outdoors. These cases highlight the importance of considering posture and biomechanical forces in the forensic evaluation of spinal fractures.