Non-uniformity of contact stress on polyethylene inserts in total knee arthroplasty.
This study examined tibiofemoral contact stresses in 15 commercially available TKR designs, using digitally imaged pressure-sensitive film. The objectives were (1) to determine the correlation between minimization of spatial mean contact stress and minimization of the amount of overloaded (>10 MPa) polyethylene contact area, and (2) to ascertain the difference in contact stresses for machined versus moulded polyethylene inserts. The data showed that there was no statistically significant (design rank-order) correlation of spatial mean contact stress with overloaded polyethylene area. The data also showed that machining cutter preparation of the polyethylene insert caused substantial local contact stress non-uniformities that corresponded to the pattern of grossly visible machining marks.
Bristol
RE
R
Departments of Orthopaedic Surgery, Mechanical Engineering, and Biomedical Engineering, University of Iowa, Iowa City IA, USA.
Fitzpatrick
DC
D
Brown
TD
T
Callaghan
JJ
J