Sara Heltzel

Classifying and Standardizing Panfacial Trauma With a New Bony Facial Trauma Score

Importance The practice of facial trauma surgery would benefit from a useful quantitative scale that measures the extent of injury. Objective To develop a facial trauma scale that incorporates only reducible fractures and is able to be reliably communicated to health care professionals. Design and Setting A cadaveric tissue study was conducted from October 1 to 3, 2014. Ten cadaveric heads were subjected to various degrees of facial trauma by dropping a fixed mass onto each head. The heads were then imaged with fine-cut computed tomography. A Bony Facial Trauma Scale (BFTS) for grading facial trauma was developed based only on clinically relevant (reducible) fractures. The traumatized cadaveric heads were then scored using this scale as well as 3 existing scoring systems. Regression analysis was used to determine correlation between degree of incursion of the fixed mass on the cadaveric heads and trauma severity as rated by the scoring systems. Statistical analysis was performed to determine correlation of the scores obtained using the BFTS with those of the 3 existing scoring systems. Scores obtained using the BFTS were not correlated with dentition (95% CI, –0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (95% CI, –0.068 to 0.944; P = .08). Main Outcome Measures Facial trauma scores. Results Among all 10 cadaveric specimens (9 male donors and 1 female donor; age range, 41-87 years; mean age, 57.2 years), the facial trauma scores obtained using the BFTS correlated with depth of penetration of the mass into the face (odds ratio, 4.071; 95% CI, 1.676-6.448) P = .007) when controlling for presence of dentition and age. The BFTS scores also correlated with scores obtained using 3 existing facial trauma models (Facial Fracture Severity Scale, rs = 0.920; Craniofacial Disruption Score, rs = 0.945; and ZS Score, rs = 0.902; P < .001 for all 3 models). In addition, the BFTS was found to have excellent interrater reliability (0.908; P = .001), which was similar to the interrater reliability of the other 3 tested trauma scales. Scores obtained using the BFTS were not correlated with dentition (odds ratio, .482; 95% CI, –0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (odds ratio, .436; 95% CI, –0.068 to 0.944; P = .08). Conclusions and Relevance Facial trauma severity as measured by the BFTS correlated with depth of penetration of the fixed mass into the face. In this study, the BFTS was clinically relevant, had high fidelity in communicating the fractures sustained in facial trauma, and correlated well with previously validated models. Level of Evidence NA.

Blunt impacts to the back: Biomechanical response for model development

The development of advanced injury prediction models requires biomechanical and injury tolerance information for all regions of the body. While numerous studies have investigated injury mechanics of the thorax under frontal impact, there remains a dearth of information on the injury mechanics of the torso under blunt impact to the back. A series of hub-impact tests were performed to the back surface of the mid-thorax of four mid-size male cadavers. Repeated tests were performed to characterize the biomechanical and injury response of the thorax under various impact speeds (1.5m/s, 3m/s and 5.5m/s). Deformation of the chest was recorded with a 59-gage chestband. Subject kinematics were also recorded with a high-speed optoelectronic 3D motion capture system. In the highest-severity tests, peak impact forces ranged from 6.9 to 10.5 kN. The peak change in extension angle measured between the 1st thoracic vertebra and the lumbar spine ranged from 39 to 62°. The most commonly observed injuries were strains of the costovertebral/costotransverse joint complexes, rib fractures, and strains of the interspinous and supraspinous ligaments. The majority of the rib fractures occurred in the rib neck between the costovertebral and costotransverse joints. The prevalence of rib-neck fractures suggests a novel, indirect loading mechanism resulting from bending moments generated in the rib necks caused by motion of the spine. In addition to the injury information, the biomechanical responses quantified here will facilitate the future development and validation of human body models for predicting injury risk during impact to the back.

Pelvic restraint cushion sled test evaluation of pelvic forward motion

ABSTRACT Objective: This study was designed to evaluate the performance of a pelvic restraint cushion (PRC), a submarining countermeasure that deploys under the thighs when a crash is detected in order to block the forward motion of the pelvis. Methods: Sled tests approximating low- and high-speed frontal impacts were conducted with 4 female postmortem human subjects (PMHS) restrained by a lap and shoulder belt in the right front passenger seat. The subjects were tested with and without a PRC. Results: The PRC is effective in reducing forward motion of the PMHS pelvis and reduces the risk of injury due to lap belt loading in a high-speed frontal crash. Conclusions: Although small sample size limits the utility of the studys findings, the results suggest that the PRC can limit pelvic forward motion and that pelvic injury due to PRC deployment is not likely.