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design seems to solved completely this issue. This study sustains PSNA, DBSNG, PGRD asreliable measures to predict scapular notching. Besides eccentric SMR glenosphere seems toincrease R.O.M. mostly in flexion, abduction and adduction.FiguresFigure 1 Figure 2Thursday, October 7, 2010, 10:20-11:00Session A3: Bearing Mobility IssuesPost-Cam Kinematics in TKP*Hendrik Delport - AZ Nikolaas - Sint Niklaas, BelgiumWard Bartels - Catholic University - Leuven, BelgiumScott A. Banks - University of Florida - Gainesville, FL, USAJos Van der Sloten - Catholic University - Leuven, BelgiumJohan Bellemans, - Catholic University - Leuven, Belgium*Email: hendrik.delport@telenet.beIn general TKA can be divided into two distinct groups : cruciate retaining and cruciatesubstituting. The cam and post of the latter system is in fact a mechanical substitution of theintricate posterior cruciate ligament.In our previous work we and many other investigatorshave focused on the movement of the femoral component relative to the tibial tray. Littleinformation is available about the relative movement between the cam part of the femoralcomponent and the post of the tibial insert.In this study we determine the distance and thechanges in distance between the cam of the femoral component and the tibial post duringextension, flexion at 90° and full flexion.The secondary purpose is to analyse possibledifferences between FBPS and MBPS TKA.Methods :12 subjects’ knees were imaged using fluoroscopy from extension over 90° to maximumkneeling flexion. The images were digitized. The 3-dimensional (3D) position and orientationof the implant components were determined using model-based shape-matching techniques,manual matching, and image-space optimization routines. The implant surface model wasprojected onto the geometry-corrected image, and its 3D pose was iteratively adjusted to matchits silhouette with the silhouette of the subject’s TKA components. The results of thisshapematching process have standard errors of approximately 0.5° to 1.0° for rotations and 0.5mm to 1.0 mm for translations in the sagittal plane.Joint kinematics were determined from the3D pose of each TKA component using the 3-1-2 Cardan angle convention. This processresulted in a distance map of the femoral and tibial surfaces, from which the minimumseparations were determined for the purpose of this study between cam and post (fig1.).Separation distances between the tibial polyethylene (PE) insert’s post and the femoralfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]