Correlation between pre-operative periprosthetic bone density and post-operative bone loss in THA can be explained by strain-adaptive remodelling

Periprosthetic adaptive bone remodelling after total hip arthroplasty can b e simulated in computer models, combining bone remodelling theory with fini te element analysis. Patient specific three-dimensional finite element mode ls of retrieved bone specimens from an earlier bone densitometry (DEXA) stu dy were constructed and bone remodelling simulations performed. Results of the simulations were analysed both qualitatively and quantitatively. Patter ns of predicted bone loss corresponded very well with the DEXA measurements on the retrievals. The amount of predicted bone loss, measured quantitativ ely by simulating DEXA on finite element models, was found to be inversely correlated with the initial bone mineral content. It was concluded that the same clinically observed correlation can therefore be explained by mechani cally induced remodelling. This finding extends the applicability of numeri cal pre-clinical testing to the analysis of interaction between implant des ign and initial state of the bone. (C) 1999 Elsevier Science Ltd. All right s reserved.