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Femoral Fracture Pattern and Its Role in Determining Direction of Impact in a Pedestrian Case
Author(s) -
Porta David J.,
Kress Tyler A.
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.902.22
Subject(s) - fracture (geology) , tension (geology) , geology , cadaver , pedestrian , oblique case , femoral shaft , anatomy , wedge (geometry) , bone fracture , orthodontics , compression (physics) , materials science , medicine , engineering , geotechnical engineering , intramedullary rod , mathematics , composite material , radiology , geometry , linguistics , philosophy , transport engineering
There is a long history of anatomical and biomechanical research on human cadaver long bones for the worthy goal of determining tolerance to impact. Such data can assist design engineers with the enhancement of safety features in motor vehicles, sporting equipment, etc. In addition to collecting valuable force data, details learned about anatomical fracture patterns can benefit investigators who reconstruct mechanisms of injury in forensic cases. For example, fracture pattern can be used to distinguish torsional versus bending type injuries. After hundreds of long bone impact experiments, and detailed observations on the resulting fracture patterns, it is clear that when an impact occurs to the diaphysis of a long bone, the fracture initiates on the opposite side. While the impact compresses the tissue on the contact side, the shaft of the bone is placed in tension on the opposite side. The result is fracture lines that radiate from the side in tension back toward the contact side which is in compression. When one or more of these tension lines travels the entire diameter of the bone, a fragment or fragments are formed and one can note a pattern‐ e.g. oblique, transverse, wedge, segment, etc. In addition to the basic fracture pattern, observation of the incomplete fracture/tension lines (which may not be visible on standard X‐ray) can sometimes be valuable. We present a case in which a pediatric pedestrian was struck and killed by a car and there were no witnesses to the event. Femoral fragments were retained from the autopsy. The question of direction of impact became important as an attempt was made to determine if the boy had run into traffic or if he was struck while walking parallel to the lane of travel. Tension lines on the femur indicated the boy was struck from the lateral aspect. In conclusion, the study of nearly microscopic fracture anatomy can be a useful endeavor when evidence of direction of impact might enhance injury reconstruction.