Development and validation of a model for quantifying glenohumeral ligament strains during function.
Analysis of the function of glenohumeral ligaments (GHLs) during physical joint manipulations is hindered by an inability to adequately image these tissues during the movements. This restricts functional biomechanics studies only to the manoeuvres that may be replicated cadaverically. There is, however, a clinical imperative to be able to investigate complex manoeuvres that exacerbate symptoms but cannot be easily conducted physically in the laboratory. The aim of this study was to develop and validate an algorithm for a computer simulation model that allows the quantification of glenohumeral ligament lengths during function. Datasets of the humerus and scapula pair were segmented to provide individual surface meshes of the bones and insertion points of each glenohumeral ligament on both bones. An algorithm was developed in which the glenohumeral ligament attachment-to-attachment length was divided into two straight lines, plus an arc overlaying the spherical wrapping portions. The model was validated by simulating two classical cadaveric studies from the literature and comparing results. Predictions from the model were qualitatively similar to the results of the two cadaveric studies by a factor of 91.7% and 81.8%, respectively. Algorithm application will allow investigation of functional loading of the glenohumeral ligaments during simulated complex motions. This could then be used to provide diagnostic understanding and thus, inform surgical reconstruction.
Department of Bioengineering, Imperial College London, UK. hippolite.amadi00@imperial.ac.uk
Hippolite O
HO
Amadi
Anthony M J
AM
Bull
Roger J H
RJ
Emery
D000465:Algorithms; D001696:Biomechanical Phenomena; D002102:Cadaver; D003198:Computer Simulation; D006801:Humans; D006811:Humerus / Q000502:physiology; D008023:Ligaments, Articular / Q000502:physiology*; D008953:Models, Anatomic; D012540:Scapula / Q000502:physiology; D012785:Shoulder Joint / Q000502:physiology*