Background: Bony fractures of the tibia and fibula are frequently encountered in car accidents involving a pedestrian and a moving vehicle. The morphological analysis of the external, but mostly of the internal surface of the fracture is fundamental for the forensic examiner in the reconstruction of the impact dynamics; there are two methods to perform this analysis: fractography, the gold standard method, or micro-CT, a recently introduced method whose applications in forensic traumatology are arousing great interest. Aim of the study: The aim of the present study is to analyse experimentally produced leg fractures by both fractography (gold standard) and micro-CT (virtual fractography) in order to calculate the accuracy of the micro-CT with respect to the gold standard method and the positive predictive value of the internal fracture surface characteristics observed using the two methods, with the aim of establishing whether micro-radiological analysis can be a valid alternative to the gold standard technique. Materials and Methods: 55 amputated human legs donated to science were divided into four groups, one for each direction of force application, and impacted using a three-point bending experiment, resulting in 92 fractured bone samples. These samples were analysed by both fractography and micro-CT, observing the presence of the chip fragment and the five parameters characterising the internal fracture surface. The data obtained from this evaluation were reported in comparison tables between micro-CT and fractography and subjected to statistical analysis. Results: our findings suggest that the accuracy of micro-CT is slightly lower than the gold standard, but is, nevertheless, quite high. In the reconstruction of the correct impact dynamics, the positive predictive value of the five internal surface parameters (bone mirror, bone hackle, arrest ridges, wake feature, cantilever curl) detected at micro-CT was the same or even higher than the one of the parameters observed in fractography, both when considered in the four groups relating to the impact directions (anterior, posterior, medial and lateral) and in the entire sample pool. Conclusions: On the basis of the results obtained, it is possible to state that virtual fractography has an adequate accuracy and has proved effective in analysing the parameters present at the level of the fracture margins; this suggests that micro-CT can be used as an alternative to fractography for the correct reconstruction of the impact dynamics of bony leg fractures in forensic traumatology.
Background: Nell’investimento di pedone sono di frequente riscontro le fratture biossee di tibia e perone. L’analisi morfologica della superficie esterna, ma soprattutto interna di frattura è fondamentale per il medico legale nella ricostruzione della dinamica d’impatto; la suddetta analisi può essere condotta mediante la frattografia, metodica gold standard, oppure tramite micro-TC, metodica di recente introduzione le cui applicazioni in traumatologia forense stanno suscitando forte interesse. Scopo dello studio: obiettivo del presente studio è analizzare fratture biossee di gamba prodotte sperimentalmente sia tramite frattografia (gold standard), sia tramite micro-TC (frattografia virtuale) al fine di calcolare l’accuratezza di quest’ultima rispetto alla metodica gold standard e il valore predittivo positivo delle caratteristiche di superficie interna di frattura osservate tramite le due metodiche, con lo scopo di stabilire se l’analisi microradiologica possa costituire una valida alternativa alla tecnica gold standard. Materiali e Metodi: 55 gambe umane amputate e donate alla scienza sono state suddivise in quattro gruppi, uno per ogni direzione di applicazione della forza, e impattate, tramite un esperimento three point bending, ottenendo così 92 campioni ossei fratturati. Tali campioni sono stati analizzati sia in frattografia che in micro-TC, osservando la presenza del chip fragment e dei cinque parametri che caratterizzano la superficie interna di frattura. I dati ottenuti da questa valutazione sono stati riportati in tabelle di confronto tra micro-TC e frattografia e sottoposti ad un’analisi statistica. Risultati: è emerso che l’accuratezza della micro-TC è lievemente inferiore rispetto al gold standard, ma risulta, tuttavia, piuttosto elevata. Nella ricostruzione della corretta dinamica d’impatto, il valore predittivo positivo dei cinque parametri di superficie interna (bone mirror, bone hackle, arrest ridges, wake feature, cantilever curl) rilevati alla micro-TC è risultato sostanzialmente sovrapponibile o addirittura superiore a quello dei parametri osservati in frattografia, sia quando considerati nei quattro gruppi relativi alle direzioni d’impatto (anteriore, posteriore, mediale e laterale), sia nell’intero pool campionario. Conclusioni: sulla base dei risultati ottenuti, è possibile affermare che la frattografia virtuale abbia un’accuratezza adeguata e si sia dimostrata efficace nell’analizzare i parametri presenti a livello dei margini di frattura; ciò suggerisce che la micro-TC possa essere utilizzata in alternativa alla frattografia ai fini della corretta ricostruzione della dinamica di produzione di fratture biossee di gamba in traumatologia forense.
Potenzialità e limiti della frattografia virtuale nella ricostruzione della dinamica d'impatto di fratture biossee di gamba.
TODESCO, GIORGIA
2022/2023
Abstract
Background: Bony fractures of the tibia and fibula are frequently encountered in car accidents involving a pedestrian and a moving vehicle. The morphological analysis of the external, but mostly of the internal surface of the fracture is fundamental for the forensic examiner in the reconstruction of the impact dynamics; there are two methods to perform this analysis: fractography, the gold standard method, or micro-CT, a recently introduced method whose applications in forensic traumatology are arousing great interest. Aim of the study: The aim of the present study is to analyse experimentally produced leg fractures by both fractography (gold standard) and micro-CT (virtual fractography) in order to calculate the accuracy of the micro-CT with respect to the gold standard method and the positive predictive value of the internal fracture surface characteristics observed using the two methods, with the aim of establishing whether micro-radiological analysis can be a valid alternative to the gold standard technique. Materials and Methods: 55 amputated human legs donated to science were divided into four groups, one for each direction of force application, and impacted using a three-point bending experiment, resulting in 92 fractured bone samples. These samples were analysed by both fractography and micro-CT, observing the presence of the chip fragment and the five parameters characterising the internal fracture surface. The data obtained from this evaluation were reported in comparison tables between micro-CT and fractography and subjected to statistical analysis. Results: our findings suggest that the accuracy of micro-CT is slightly lower than the gold standard, but is, nevertheless, quite high. In the reconstruction of the correct impact dynamics, the positive predictive value of the five internal surface parameters (bone mirror, bone hackle, arrest ridges, wake feature, cantilever curl) detected at micro-CT was the same or even higher than the one of the parameters observed in fractography, both when considered in the four groups relating to the impact directions (anterior, posterior, medial and lateral) and in the entire sample pool. Conclusions: On the basis of the results obtained, it is possible to state that virtual fractography has an adequate accuracy and has proved effective in analysing the parameters present at the level of the fracture margins; this suggests that micro-CT can be used as an alternative to fractography for the correct reconstruction of the impact dynamics of bony leg fractures in forensic traumatology.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/48120