Fig. 4

Metallic non-ferrous particles. a Conventional black metallic particulate debris (black arrows) in MoP implant (H&E × 400), birefringent PE debris is evident as blue, granular and needle-shaped particles under polarized light in inset (× 400). b Macrophagic and giant cell reaction to conventional particulate metallic debris with irregular macroparticles in multinucleated giant cells (blue arrows) with empty lacunae of methyl methacrylate orthopedic cement (black arrow) (H&E × 200), CoCr femoral head with a large band of abrasion (white arrow) secondary to edge loading due to subluxation on the distorted and cemented Ti acetabular rim (green arrow) in inset. c Oxidized metallic particulate debris in MoM HRA implant macrophages filled with tribocorrosion nanoparticle aggregates and rod/needle-shaped larger abrasion microparticles (black arrows) (H&E × 400); femoral head with osteolytic cavity (white arrow) and neo-synovium with charcoal-gray color, indicative of conventional metallic debris from edge loading in inset. d Deposits of large aggregates of greenish corrosion products in enlarged trochanteric bursa of a MoM THA implant with MAS generated at head/neck junction by mechanically assisted fretting/crevice corrosion (H&E × 100), details of particles with green (CoCrMo), red (blood-derived) and black (Ti) layers in inset (H-E × 400). e Macrophagic infiltrate containing predominantly tribocorrosion metallic nanoparticles in MoM HRA implant, semithin section (toluidine blue × 400); macrophagic infiltrate in inset (H&E × 400). f Macrophage infiltrate containing predominantly tribocorrosion metallic nanoparticles (white arrow) and microplate of corrosion product from head-neck junction in a multinucleated giant cell (black arrow) of a MoM THA implant with MAS, semithin section (toluidine blue × 400); macrophage infiltrate in inset (H&E × 400). g Macrophage infiltrate containing irregular metallic nanoparticle aggregates in a non-MoM THA with CoCr DMN, semithin section (toluidine blue × 400) and giant cell with a large aggregate of nanoparticles/corrosion product (white arrow), semithin section, in the upper right inset (toluidine blue × 400), macrophage infiltrate in the lower right inset (H&E × 400). h Microplates of corrosion particle aggregates generated at fixation device screw-plate interface (H&E × 100). Metallic plate and metallic screws with corrosion observed at the screw head/threaded body junction (white arrow) in inset