title: Head and neck injury patterns in fatal falls: epidemiologic and biomechanical considerations.
abstract: Fatal falls often involve a head impact, which are in turn associated with a fracture of the skull or cervical spine. Prior authors have noted that the degree of inversion of the victim at the time of impact is an important predictor of the distribution of skull fractures, with skull base fractures more common than skull vault fractures in falls with a high degree of inversion. The majority of fatal fall publications have focused on skull fractures, and no research has described the association between fall circumstances and the distribution of fractures in the skull and neck. In the present study, we accessed data regarding head and neck fractures resulting from fatal falls from a Swedish autopsy database for the years 1992-2010, for the purposes of examining the relationships between skull and cervical spine fracture distribution and the circumstances of the fatal fall. Out of 102,310 medico-legal autopsies performed there were 1008 cases of falls associated with skull or cervical spine fractures. The circumstances of the falls were grouped in 3 statistically homogenous categories; falls occurring at ground level, falls from a height of <3 m or down stairs, and falls from ≥3 m. Only head and neck injuries and fractures that were associated with the fatal CNS injuries were included for study, and categorized as skull vault and skull base fractures, upper cervical injuries (C0-C1 dislocation, C1 and C2 fractures), and lower cervical fractures. Logistic regression modeling revealed increased odds of skull base and lower cervical fracture in the middle and upper fall severity groups, relative to ground level falls (lower cervical <3 m falls, OR = 2.55 [1.32, 4.92]; lower cervical ≥3 m falls, OR = 2.23 [0.98, 5.08]; skull base <3 m falls, OR = 1.82 [1.32, 2.50]; skull base ≥3 m falls, OR = 2.30 [1.55, 3.40]). C0-C1 dislocations were strongly related to fall height, with an OR of 8.3 for ≥3 m falls versus ground level. The findings of increased odds of skull base and lower cervical spine fracture in falls from a height are consistent with prior observations that the risk of such injuries is related to the degree of victim inversion at impact. The finding that C0-C1 dislocations are most common in falls from more than 3 m is unique, an indication that the injuries likely result from high energy shear forces rather than pure tension, as previously thought.
authors.affiliation: Department of Public Health & Preventive Medicine, Oregon Health & Science University, Portland, OR, USA; Section of Forensic Medicine, Umeå University, Umeå, Sweden; Department of Forensic Medicine, Aarhus University, Aarhus, Denmark. Electronic address: forensictrauma@gmail.com.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Freeman
authors.affiliation: Section of Forensic Medicine, Umeå University, Umeå, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Eriksson
authors.affiliation: Department of Public Health & Preventive Medicine, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Wendy
authors.initials: W
authors.lastname: Leith
mesh_terms: D000058:Accidental Falls / Q000401:mortality*; D000328:Adult; D017677:Age Distribution; D001269:Atlanto-Occipital Joint / Q000293:injuries / Q000473:pathology; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000293:injuries* / Q000473:pathology; D016208:Databases, Factual; D005260:Female; D049429:Forensic Pathology; D006801:Humans; D004204:Joint Dislocations / Q000401:mortality / Q000473:pathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017678:Sex Distribution; D012887:Skull Fractures / Q000401:mortality / Q000473:pathology*; D016103:Spinal Fractures / Q000401:mortality / Q000473:pathology*; D013548:Sweden / Q000453:epidemiology
keywords: Autopsy; Biomechanics; C0–C1 dislocation; Cervical spine fracture; Falls; Skull base fracture; Skull vault fracture