Histological characteristics of periprosthetic tissue around metal on metal hip prostheses

Abstract

Background:The most noteworthy advantage of metal-on-metal (MoM) total hip prostheses is low were rate and avoidance of polyethylene (PE) particles. The aim of the present study was to evaluate the histological characteristics of the tissue around MoM THR and to determine if perivascular lymphoid aggregates are characteristic findings in periprosthetic tissue around MoM prostheses.Material and methods: Tissue samples from 26 revised THRs with MoM articulation and 36 samples from two control groups: metal on polyethylene (MoPE) and ceramic on polyethylene (AloPE) were analysed. Histopathological and immunohistochemical analyses of periprosthetic tissue samples were performed in order to determine general cellular features. Semi-quantitave rating method to classify the numbers of macrophages, giant cells, lymphocytes, as well as extend of necrosis was used. In the second part of the study tissue form 544consecutive THRs were analysed and cases with Oxford ALVAL scoring system 2+ and 3+ were selected regardless the type of prosthesis.