Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue

Abstract

BackgroundThe identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination.MethodsThe cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles.ResultsAll implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis.ConclusionsThe HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

Solochrome cyanine: A histological stain for cobalt-chromium wear particles in metal-on-metal periprosthetic tissues

“…Co-Cr metal wear particles have been subcategorised into larger conventional metallic particles generated by adhesion/abrasion and smaller (mainly nano-size) corrosion metal particles which are produced by tribocorrosion, the process of degradation of the surface of metal implants due to the combined action of mechanical loading and electrochemical corrosion [3, 4, 14]. Corrosion metal particles are abundant in MoM periprosthetic tissues and have a shape which varies from round/globular to rod/needle-like ultrastructurally [2, 11, 28, 29]; these particles can appear green-yellow or yellow-brown histologically and have been shown by energy dispersive X-ray spectroscopy to have a variable metal composition with a discrete Cr-peak [13, 28, 29].…”

“…Co-Cr particles are too tiny to be visible under the light microscope but small aggregates of these particles or shards of the metal implant can be identified histologically in MoM periprosthetic tissues [12, 13]. In routinely stained (haematoxylin-eosin) histological sections, Co-Cr particles within the cytoplasm of phagocytic cells may appear translucent/pink, slate blue/grey, green/yellow or brown/black in colour; this variable morphology may reflect differences in particle size/aggregation and/or corrosion and can make it difficult to identify Co-Cr particles with certainty in histological preparations [12–14]. Non-MoM total hip arthroplasties that employ a modular Co-Cr femoral stem also generate metal wear debris and uncommonly this can cause similar (MoM-associated) pathology and complications [15, 16].…”

“…Accurate identification of implant-derived wear particles in periprosthetic tissues is important in the histological assessment of implant failure [12–14]. Co-Cr particles need to be distinguished from wear particles derived from other metal or polymer implant components as well as endogenous metal/ non-metal tissue products such as haemosiderin and fibrin.…”

Recurrent arthrocele and sterile sinus tract formation due to ceramic wear as a differential diagnosis of periprosthetic joint infection — a case report

“…However, wear-induced ceramic particles are difficult to detect by conventional histology, if at all, as the size ranges from 20 to 100 nm and only in some cases up to several micrometers (Perino et al. 2018).…”

Histopathologische Differenzialdiagnostik von Kristall-Arthritiden

“…Der Partikelalgorithmus (▶ Abb. 2) führt in einer systematischen Weise die in der Literatur bereits beschriebenen histopathologischen Kennzeichen der Partikeltypen zusammen [3]. Dieser basiert auf 3 verschiedenen histopathologischen Grundkriterien und stellt die pathogenetisch wesentlichen Partikeltypen und Abgrenzung zu partikelartigen Artefakten gegenüber: 1. endogene kristallische Partikel, 2. exogene Gelenkprothesen-Material-Typen und 3. partikelartige Artefakte.…”