“…Analysis of recent literature also shows that the application of Neer’s classification is not standardized [ 11 , 12 ]. While other classification systems have been proposed and utilized, currently no classification system defines a spatial reference frame in which to describe displacements [ 13 , 14 , 15 , 16 , 17 , 18 ]. Meanwhile, displacements of each fragment can occur in independent planes with associated rotations and translations in three dimensions.…”