A new trichrome technique for PMMA embedded percutaneous implants for the study and characterization of epithelial integration

Abstract

Poly(methylmethacrylate) (PMMA) embedding is routinely used in histomorphometry to analyze the periprosthetic tissue response to the presence of an implant in situ. However, the embedment process can limit the variety of stains that can be successfully used to highlight different tissue types within the periprosthetic tissue. In this study, a new staining protocol, the modified trichrome method, was developed to simultaneously label the collagen fiber matrix, epithelial tissue morphology, vascular network, granulation tissue, and fibrous capsule that surround the percutaneous implant. The new staining technique was compared to established histological evaluation protocols, namely Masson’s trichrome and hematoxylin and eosin (H&E) protocols. The newly developed staining protocol for analyzing implant–soft tissue integration was significantly more effective in identifying cellular and tissue structures than previously established techniques. The detail found with the modified trichrome allows a high degree of structural quantification. The ultimate goal of the present research is to improve the long term soft tissue integration of implants made from different biomaterials. The modified trichrome can benefit translational studies through a more accurate quantification of both skin attachment mechanism and cellular response to the presence of percutaneous biomaterials.

Keywords:

• Hematoxylin
• Neutral red
• Percutaneous
• PMMA
• Trichrome

This material is based upon a research study supported by NIH grant no. IRC1AR058356-01. The study is also supported, in part, by the office of Research and Development Rehabilitation R&D Services, DVA SLC Health Care System and the Department of Orthopaedics, University of Utah School of Medicine. Acknowledgement is given to the Albert and Margaret Hofmann Chair and Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT, USA.