PMID- 30010420 OWN - NLM STAT- MEDLINE DCOM- 20190510 LR - 20190510 IS - 1538-957X (Electronic) IS - 1538-9588 (Linking) VI - 19 IP - sup2 DP - 2018 TI - Computational modeling and analysis of thoracolumbar spine fractures in frontal crash reconstruction. PG - S32-S39 LID - 10.1080/15389588.2018.1498090 [doi] AB - OBJECTIVE: This study aimed to reconstruct 11 motor vehicle crashes (6 with thoracolumbar fractures and 5 without thoracolumbar fractures) and analyze the fracture mechanism, fracture predictors, and associated parameters affecting thoracolumbar spine response. METHODS: Eleven frontal crashes were reconstructed with a finite element simplified vehicle model (SVM). The SVM was tuned to each case vehicle and the Total HUman Model for Safety (THUMS) Ver. 4.01 was scaled and positioned in a baseline configuration to mimic the documented precrash driver posture. The event data recorder crash pulse was applied as a boundary condition. For the 6 thoracolumbar fracture cases, 120 simulations to quantify uncertainty and response variation were performed using a Latin hypercube design of experiments (DOE) to vary seat track position, seatback angle, steering column angle, steering column position, and D-ring height. Vertebral loads and bending moments were analyzed, and lumbar spine indices (unadjusted and age-adjusted) were developed to quantify the combined loading effect. Maximum principal strain and stress data were collected in the vertebral cortical and trabecular bone. DOE data were fit to regression models to examine occupant positioning and thoracolumbar response correlations. RESULTS: Of the 11 cases, both the vertebral compression force and bending moment progressively increased from superior to inferior vertebrae. Two thoracic spine fracture cases had higher average compression force and bending moment across all thoracic vertebral levels, compared to 9 cases without thoracic spine fractures (force: 1,200.6 vs. 640.8 N; moment: 13.7 vs. 9.2 Nm). Though there was no apparent difference in bending moment at the L1-L2 vertebrae, lumbar fracture cases exhibited higher vertebral bending moments in L3-L4 (fracture/nonfracture: 45.7 vs. 33.8 Nm). The unadjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 9 of the 11 cases (sensitivity = 1.0; specificity = 0.6). The age-adjusted lumbar spine index correctly predicted thoracolumbar fracture occurrence for 10 of the 11 cases (sensitivity = 1.0; specificity = 0.8). The age-adjusted principal stress in the trabecular bone was an excellent indicator of fracture occurrence (sensitivity = 1.0; specificity = 1.0). A rearward seat track position and reclined seatback increased the thoracic spine bending moment by 111-329%. A more reclined seatback increased the lumbar force and bending moment by 16-165% and 67-172%, respectively. CONCLUSIONS: This study provided a computational framework for assessing thoracolumbar fractures and also quantified the effect of precrash driver posture on thoracolumbar response. Results aid in the evaluation of motor vehicle crash-induced vertebral fractures and the understanding of factors contributing to fracture risk. FAU - Ye, Xin AU - Ye X AUID- ORCID: 0000-0002-4750-9731 AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. FAU - Gaewsky, James P AU - Gaewsky JP AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. FAU - Jones, Derek A AU - Jones DA AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. FAU - Miller, Logan E AU - Miller LE AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. FAU - Stitzel, Joel D AU - Stitzel JD AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. FAU - Weaver, Ashley A AU - Weaver AA AUID- ORCID: 0000-0002-4383-0106 AD - a Wake Forest University School of Medicine , Winston-Salem , North Carolina. AD - b Virginia Tech-Wake Forest University Center for Injury Biomechanics , Winston-Salem , North Carolina. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20181010 PL - England TA - Traffic Inj Prev JT - Traffic injury prevention JID - 101144385 SB - IM MH - *Accidents, Traffic MH - Adult MH - Aged MH - Aged, 80 and over MH - Computer Simulation MH - Female MH - Humans MH - Lumbar Vertebrae/*injuries/pathology MH - Male MH - Middle Aged MH - Posture MH - Spinal Fractures/classification/etiology/*pathology MH - Thoracic Vertebrae/*injuries/pathology MH - Young Adult OTO - NOTNLM OT - Finite element model OT - crash reconstruction OT - design of experiment OT - thoracolumbar spine fracture EDAT- 2018/07/17 06:00 MHDA- 2019/05/11 06:00 CRDT- 2018/07/17 06:00 PHST- 2018/07/17 06:00 [pubmed] PHST- 2019/05/11 06:00 [medline] PHST- 2018/07/17 06:00 [entrez] AID - 10.1080/15389588.2018.1498090 [doi] PST - ppublish SO - Traffic Inj Prev. 2018;19(sup2):S32-S39. doi: 10.1080/15389588.2018.1498090. Epub 2018 Oct 10.