Local Biological Reactions and Pseudotumor-Like Tissue Formation in relation to Metal Wear in a Murine In Vivo Model

Abstract

Metal wear debris and released ions (CoCrMo), which are widely generated in metal-on-metal bearings of hip implants, are also found in patients with metal-on-polyethylene bearings due to the mechanically assisted crevice corrosion of modular taper junctions, including head-neck and neck-stem taper interfaces. The resulting adverse reactions to metal debris and metal ions frequently lead to early arthroplasty revision surgery. National guidelines have since been published where the blood metal ion concentration of patients must consistently be monitored after joint replacement to prevent serious complications from developing after surgery. However, to date, the effect of metal particles and metal ions on local biological reactions is complex and still not understood in detail; the present study sought to elucidate the complex mechanism of metal wear-associated inflammation reactions. The knee joints in 4 groups each consisting of 10 female BALB/c mice received injections with cobalt chrome ions, cobalt chrome particles, and ultra-high-molecular-weight polyethylene (UHMWPE) particles or PBS (control). Seven days after injection, the synovial microcirculation and knee joint diameter were assessed via intravital fluorescence microscopy followed by histological evaluation of the synovial layer. Enlarged knee diameter, enhanced leukocyte to endothelial cell interactions, and an increase in functional capillary density within cobalt chrome particle-treated animals were significantly greater than those in the other treatment groups. Subsequently, pseudotumor-like tissue formations were observed only in the synovial tissue layer of the cobalt chrome particle-treated animals. Therefore, these findings strongly suggest that the cobalt chrome particles and not metal ions are the cause for in vivo postsurgery implantation inflammation.

Effect of Chromium and Molybdenum Increment on the Crystal Structure, Nanoindentation, and Corrosion Properties of Cobalt‐Based Alloys

“…[ 24 ] Although the presence of Cr, Co, and Mo is essential for certain metabolic activities in the human body, [ 25 ] the increment from a certain level is ought to be unfavorable due to potential biological inflammatory reactions and pseudotumor‐like tissue formation associated with wear phenomena. [ 24,26 ] Such corrosion of debris and its monitoring is part of ongoing studies. [ 27 ]…”

Metal wear debris generation in primary total knee arthroplasty: is it an issue?

“…However, the effects of metal wear debris (metal particles and ions), which is around 1/10 th of the total wear debris, have been underestimated. 4 Metal wear can cause local and systemic adverse effects (3,4,(6)(7)(8)(9)(10).…”

The Expression Levels of Toll-like Receptors after Metallic Particle and Ion Exposition in the Synovium of a Murine Model

“…Numerous studies for Co28Cr6Mo implants have been conducted in vivo and in vitro and indicated that Co28Cr6Mo nanoparticles were cytotoxic and prompted cell apoptosis, and at higher dose, necrosis, with inflammatory reactions [30]. Furthermore, utilizing Co28Cr6Mo particles and ions, researchers once demonstrated that Co28Cr6Mo particles could induce more intense sterile inflammatory responses than Co28Cr6Mo ions in the synovial membrane in vivo [31]. According to some studies, wear debris-induced inflammation might be mitigated by specific pharmacological blockade of one or more of these TLRs [11,32].…”