ABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
ABSTRACT
Metal-on-metal (MoM) hip arthroplasties produce abundant implant-derived wear debris composed mainly of cobalt (Co) and chromium (Cr). Cobalt-chromium (Co-Cr) wear particles are difficult to identify histologically and need to be distinguished from other wear particle types and endogenous components (e.g., haemosiderin, fibrin) which may be present in MoM periprosthetic tissues. In this study we sought to determine whether histological stains that have an affinity for metals are useful in identifying Co-Cr wear debris in MoM periprosthetic tissues. Histological sections of periprosthetic tissue from 30 failed MoM hip arthroplasties were stained with haematoxylin-eosin (HE), Solochrome Cyanine (SC), Solochrome Azurine (SA) and Perls' Prussian Blue (PB). Sections of periprosthetic tissue from 10 cases of non-MoM arthroplasties using other implant biomaterials, including titanium, ceramic, polymethylmethacrylate (PMMA) and ultra-high molecular weight polyethylene (UHMWP) were similarly analysed. Sections of 10 cases of haemosiderin-containing knee tenosynovial giant cell tumour (TSGCT) were also stained with HE, SC, SA and PB. In MoM periprosthetic tissues, SC stained metal debris in phagocytic macrophages and in the superficial necrotic zone which exhibited little or no trichrome staining for fibrin. In non-MoM periprosthetic tissues, UHMWP, PMMA, ceramic and titanium particles were not stained by SC. Prussian Blue, but not SC or SA, stained haemosiderin deposits in MoM periprosthetic tissues and TSGT. Our findings show that SC staining (most likely Cr-associated) is useful in distinguishing Co-Cr wear particles from other metal/non-metal wear particles types in histological preparations of periprosthetic tissue and that SC reliably distinguishes haemosiderin from Co-Cr wear debris.
Subject(s)
Benzenesulfonates , Coloring Agents/pharmacology , Equipment Failure Analysis/methods , Hip Joint/pathology , Metal Nanoparticles/analysis , Metal-on-Metal Joint Prostheses , Staining and Labeling/methods , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Hip/instrumentation , Azurin/chemistry , Azurin/pharmacology , Benzenesulfonates/chemistry , Benzenesulfonates/pharmacology , Chromium/chemistry , Coloring Agents/chemical synthesis , Coloring Agents/chemistry , Eosine Yellowish-(YS)/chemistry , Eosine Yellowish-(YS)/pharmacology , Ferrocyanides/chemistry , Ferrocyanides/pharmacology , Giant Cells, Foreign-Body/drug effects , Giant Cells, Foreign-Body/pathology , Hematoxylin/chemistry , Hematoxylin/pharmacology , Hip Joint/chemistry , Hip Joint/drug effects , Hip Prosthesis , Histological Techniques/methods , Humans , Macrophages/drug effects , Macrophages/pathology , Metal-on-Metal Joint Prostheses/adverse effects , Polyethylenes/analysis , Polyethylenes/chemistryABSTRACT
Reduction of a permethylpentalene zirconium(iv) chloride complex [η8-Pn*Zr(µ-Cl)3/2]2(µ-Cl)2Li·THFx with KC8 in benzene results in activation of the aromatic solvent to yield an "inverted sandwich" complex, [η8-Pn*Zr]2(µ-η6:η6-C6H6) (1). The reactions in toluene, cumene, o-xylene and m-xylene also yield analogous solvent activated triple-decker sandwich complexes, which have been structurally characterised by single-crystal X-ray diffraction. Edge energies in the Zr K-edge XANES spectra are not distinguishable between 1 and formally Zr(ii) and Zr(iv) reference compounds, suggesting a broad edge structure. DFT calculations best describe the bonding in 1 as highly covalent with frontier molecular orbitals showing almost equal contributions from benzene and the Zr-permethylpentalene fragments.
