This study was conducted to delineate the biomechanics of injury to the human cervical spine under compression-extension forces encountered in an automotive environment. In vitro dynamic loading experiments were conducted using unembalmed human cadaver cervical spines. Dynamic loading was applied using an electrohydraulic testing device at the superior end. Applied load and deformation data together with the distal generalized force histories were recorded at a sampling rate of 10,000 Hz using a modular digital data acquisition system. The mean failure compressive forces, moments, deflections, stiffness and energy capacities were 3.8 kN, 154 Nm, 15 mm, 152 N/mm, and 71 J respectively. Spinal trauma included anterior longitudinal ligament tears and posterior element fractures, with and without disruptions of the facet joints. The quantification of the strength and the documentation of trauma to the human cervical spine under dynamic loads offers the treating physician and the biomechanist a better understanding of the mechanism of injury under compression-extension forces. Since soft tissue damage from plain films are always inferential, evidence of posterior bony trauma to the human cervical spine may imply inherent anterior instability. (A)
Abstract