Forensic Epidemiologic and Biomechanical Analysis of a Pelvic Cavity Blowout Injury Associated with Ejection from a Personal Watercraft (Jet‐Ski)

Abstract

Jet-propelled personal watercraft (PWC) or jet-skis have become increasingly popular. The means of propulsion of PWC, which is a jet of water forced out of small nozzle at the rear of the craft, combined with a high risk of falling off of the seat and into close proximity with the water jet stream, raise the potential for a unique type of injury mechanism. The most serious injuries associated with PWC falls are those that occur when the perineum passes in close proximity to the jet nozzle and the high-pressure water stream enters the vaginal or rectal orifice. We describe the forensic investigation into a case of an anovaginal "blowout" injury in a passenger who was ejected from the rear seat position of a PWC and subsequently suffered life-threatening injuries to the pelvic organs. The investigation included a biomechanical analysis of the injury mechanism, a summary of prior published reports of internal pelvic injuries resulting from PWC falls as well as other water sports and activities, and a comparison of the severity of the injuries resulting from differing mechanisms using the New Injury Severity Score (NISS). The mean (± standard deviation [SD]) NISS values for reported PWC injuries [not including the NISS of 38 in this case study] were 11.2 (± 9.5), while the mean value for reported water-skiing falls was half that of the PWC group at 5.6 (± 5.2). It was concluded that the analyzed injuries were unique to a PWC ejection versus other previously described non-PWC-associated water sport injuries. It is recommended that PWC manufacturers help consumers understand the potential risks to passengers with highly visible warnings and reduce injury risk with revised seat design, and/or passenger seat "deadman" switches.

Pediatric and adolescent injury in aquatic adventure sports

“…32 When falling behind a fast moving PWC, (while the jet is propelling water to the rear of the craft), children have sustained forcible water ingress into the vagina or rectum, sometimes even fatally. 33 In Egypt, a 10 year old girl suffered severe blunt force neck trauma when she struck a rope tied between two boats while driving a PWC at high speed. 34 Handlebar straddle injuries occur when a PWC collides with a stationary object.…”

“…50 Falling off a fast moving PWC is the most common cause of immediate injury, 31 either by collision with a stationary object, another watercraft or by ingress of water into bodily cavities. 33 On the other hand, there may be some considerable delay between riding the PWC and symptom onset. For example, a 16 year old girl suffering bilateral lower extremity fractures following a PWC incident showed no evidence of head trauma, yet 30 hours later she became comatose.…”

Hydrostatic Injury Surgical Planning

“…Fortunately, rectal injuries seem to be less likely than vaginal injuries, thought to be due to the lack of sphincter at the vaginal opening. 5 …”

“…3 Without these protective measures in place, the resulting injuries are believed to occur due to over distention of the lumen of the affected organ. 2–5 Vaginal rupture has previously been shown to occur at 10 pounds per square inch, and a mere 20% thrust level in current personal watercraft can exceed 80 pounds per square inch, dependent upon proximity to the exposed orifice. 5 There are currently no cases in the literature describing injury from direct force of the water jet alone or detailing urethral injuries which would suggest that the supposed mechanism of injury is likely.…”

Reparación laparoscópica de lesión rectal por traumatismo hidrostático. Reporte de caso y revisión de la bibliografía.

“…1 Los casos descriptos de traumatismos hidrostáticos son escasos y la mayoría de ellos causaron lesiones ginecológicas. 2 Los THR inicialmente publicados fueron causados por enemas 1 o por esquí acuático. 3 Luego de una extensa búsqueda bibliográfica, se hallaron 16 casos de THR por caída de moto acuática y solo uno donde la laparoscopía tuvo lugar en el algoritmo de manejo.…”