title: Pontomedullary lacerations and concomitant head and neck injuries: their underlying mechanism. A prospective autopsy study.
abstract: It is a well-documented fact that pontomedullary lacerations (PML) occur as a result of severe craniocervical injury, but their underlying mechanism has yet to be fully clarified. The aim of this prospective study has been to give greater insight into the underlying mechanism of PML through determining the site of blunt head-impact, as well as the presence of concomitant head and neck injuries in cases of brainstem PML. A total of 56 cases with partial PML have been analysed for this study. The case group was composed of 40 men and 16 women, averaging in age 44.2 ± 19.2 years and consisting of 7 motorcyclists, 4 bicyclists, 18 car occupants, 16 pedestrians, and 10 victims of falls from a height, as well as 1 victim of a fall from standing height. The presented study has shown that there are several possible mechanisms of PML. Impact to the chin, with or without a skull base fracture, most often leads to this fatal injury, due to the impact force transmission either through the jawbone or vertebral column; most likely in combination with a fronto-posterior hyperextension of the head. Additionally, lateral head-impacts with subsequent hinge fractures and PML may also be a possible mechanism. The jawbone and other facial bones are able to act as shock absorbers, and their fracture may diminish the energy transfer towards the skull and protect the brain and brainstem from injury. The upper cervical spine can act as damper and energy absorber as well, and may prevent any occurrence of fracture to the base of the skull.
authors.affiliation: Institute of Forensic Medicine, University of Belgrade - School of Medicine, 31a Deligradska Str, 11000 Belgrade, Serbia. vladinmejl@yahoo.com
authors.forename: Vladimir
authors.initials: V
authors.lastname: Živković
authors.forename: Slobodan
authors.initials: S
authors.lastname: Nikolić
authors.forename: Veljko
authors.initials: V
authors.lastname: Strajina
authors.forename: Dragan
authors.initials: D
authors.lastname: Babić
authors.forename: Danijela
authors.initials: D
authors.lastname: Djonić
authors.forename: Marija
authors.initials: M
authors.lastname: Djurić
mesh_terms: D000058:Accidental Falls / Q000401:mortality; D000063:Accidents, Traffic / Q000401:mortality; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D002423:Cause of Death; D002574:Cervical Vertebrae / Q000293:injuries; D016009:Chi-Square Distribution; D006259:Craniocerebral Trauma / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D005260:Female; D049429:Forensic Pathology / Q000379:methods; D006801:Humans; D022125:Lacerations / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D008297:Male; D008337:Mandibular Fractures / Q000209:etiology / Q000473:pathology; D008526:Medulla Oblongata / Q000293:injuries*; D008875:Middle Aged; D009104:Multiple Trauma; D019838:Neck Injuries / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D011149:Pons / Q000293:injuries*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055771:Serbia; D020205:Skull Fracture, Basilar / Q000209:etiology / Q000473:pathology; D016103:Spinal Fractures / Q000209:etiology / Q000473:pathology; D014949:Wounds, Nonpenetrating / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D055815:Young Adult