Prospective and contemporaneous medical and economic cost studies of 144 victims of motor vehicle crashes admitted to a regional level I trauma center with multiple injuries (ISS > or = 16) revealed 122 non-ejected patients, of whom 102 required extrication (EXTRIC) from the vehicle for physical or medical reasons and 20 who did not (N group). There were no differences in age (EXTRIC, 34 +/- 17 years; N, 41 +/- 24 years), type of crash (Frontal: 57% EXTRIC, 60% N; Lateral: 32% EXTRIC, 35% N) restraint use (35% EXTRIC, 35% N), or mortality (29% EXTRIC, 30% N). However, the estimated maximum speed before the crash was higher in EXTRIC patients (50 +/- 16 mph vs. 46 +/- 18 mph N, p < 0.04), as was the change in velocity (delta V) on impact (EXTRIC 30 +/- 15 mph; N, 24 +/- 8 mph, p < 0.01). Brain injuries (51% EXTRIC vs. 35% N) and lower extremity injuries were more numerous in EXTRIC patients (59% vs. 20% N, p < 0.003) and the number of splenic, lower extremity, and pelvic injuries associated with shock was greater in EXTRIC patients, p < 0.02; as were postinjury complications. As a result, operating room costs from orthopedic and plastic surgery increased professional charges in the EXTRIC group versus the N group ($20,000, EXTRIC; $17,000, N) and critical care costs ($13,000, EXTRIC; $4,000, N) with total costs of $72,000 and $77,000, respectively. The lower extremity injuries in EXTRIC patients were primarily a result of body part contacts with intrusions (CIs) of the car occupant compartment structures [73% with vs. 24% without (p < 0.0001)]. In lateral MVCs, brain injuries were also more commonly associated with CIs of the side window frame or A pillar (72% CI vs. 25% no CI; p < 0.035); but as a whole in MVCs in which extrication was necessary, lower extremity injuries from instrument panel or toepan CIs appeared more frequent than those resulting from contacts only (p < 0.0001). In EXTRIC patients, 69% of those in shock had CI injuries, and 80% of the deaths in the EXTRIC group were associated with CI injury. These data suggest that measures designed to prevent CIs by strengthening car passenger compartment structures may reduce the incidence of severe brain and lower extremity injuries and may reduce the need for extrication after MVCs.