Development of a computational technique to measure cartilage contact area

In vitro assessment of the contact mechanics of reverse-engineered distal humeral hemiarthroplasty prostheses

“…Joint congruency may have decreased and changes in contact distribution would reflect a new equilibrium joint alignment. Previous studies have reported that the cartilage thickness distributions across the ulnohumeral and radiocapitellar joints are not uniform (Rafehi et al, 2012;Schenck et al, 1994;Tillmann, 1978;Willing et al, 2013Willing et al, , 2014. This means neglecting the cartilage thickness would have a varied result throughout the different contact regions.…”

“…The CT data was imported into Mimics v14.12 (Materialise, Leuven, Belgium), and the distal humeral bone geometry was extracted using threshold based segmentation, which included any voxel with an attenuation value of 250 HU or greater Willing et al, 2013Willing et al, , 2014. Models were wrapped, exported in the stereolithography (STL) format, and remeshed using a radial basis function in Matlab (The Mathworks, Natick, MA, USA).…”

“…Bone models included all voxels with an attenuation value of 250 HU or greater. Cartilage models included all voxels with an attenuation value of −700 HU or greater Willing et al, 2014;Yeung et al, 2013). The attached fiducial markers were also segmented from the CT scan data, and a sphere fit algorithm was used to calculate the centroid of each fiducial in the CT scan data, and the fiducial digitization data.…”

“…The attached fiducial markers were also segmented from the CT scan data, and a sphere fit algorithm was used to calculate the centroid of each fiducial in the CT scan data, and the fiducial digitization data. All of the models were registered to the experiment data using a fiducial-based registration method Lapner et al, 2014;Willing et al, 2013Willing et al, , 2014. Model positions were further refined via alignment to their corresponding surface digitizations using an ICP alignment procedure.…”

Sensitivity study of the morphometric fitting on the pressure field inside ankle joints

“…Although several studies of other human joints are reported in the literature, studies centred on the morphology of the bones building the ankle or talo-crural joint are scarce. Only a few works deal with ankle joint geometrical measurements [1][2][3]. The ankle joint may be modelled as bearing from an engineering point of view [4] where the tibia and fibula form the mortise (socket) into which the talus fits thus forming the hinge joint.…”