Table 2.

Morphologic and material-related factors of special note in the review process

Morphologic indices of local biologic reactions	Material and design factors
Necrosis and/or apoptosis	CoCr particles and/or ions
Diffuse lymphocytes	Corrosion products
Perivascular lymphocytes	Other metal particles (eg, titanium)
Plasma cells	PE particles
Actual vasculitis	Ceramic particles
Macrophages and giant cells	PMMA and/or contrast (barium, zirconium)
Eosinophils	Monoblock versus modular heads/sleeves
Acute inflammation (neutrophils)	Other modularity
Normal (not inflamed)

CoCr = cobalt-chromium; PE = polyethylene; PMMA = polymethylmethacrylate.