QUANTITATIVE TRAUMATOMECHANICS OF PELVIC FRACTURE

Quasistatic loading of the isolated pelvis and of the pelvis in situ i s reported; dynamic loading with an impactor and on 90 degrees car/car side impact are then considered. The isolated pelvis was loaded later ally at the ala of the ilium and the pelvis in situ in the anterior-po sterior direction in the area of the symphysis with universal dynamome ter; the loading profile was a rigid disk 150 mm in diameter. Some dyn amic tests were performed with an impactor with rigid disk 80 mm in di ameter as impact surface; the impact was applied against the trochante r major area at a velocity of 30-35 km/h. Otherwise, the pelvic area w as stressed by impact through the intrusion of the car side or by impa ction of the pelvis against a rigid wall. In the tests conducted with isolated pelves, forces of 850-4850 N were measured; pelvic fractures were observed, specifically fractures of the acetabular margin, pubic bone, and ischium, and comminuted fractures of the symphysis and the i liosacral. In the impactor tests, forces of 6.5-11 kN were enough to c ause, pelvic fracture except in one case, and fractures of the femoral neck were found in some cases in addition. With quasistatic anterior- posterior loading of the pelvis in situ, forces of 4700-10 000 N were measured in cases in which fractures were found.