Published online Nov 18, 2014. doi: 10.5312/wjo.v5.i5.660
Revised: June 20, 2014
Accepted: July 12, 2014
Published online: November 18, 2014
Core tip: Valuable lessons have been learnt from the era of metal-on-metal total hip arthroplasty. We present a review of the concepts introduced by Willert and Semlitsch in 1977, along with further developments made in the understanding of periprosthetic tissue reactions to metallic debris. We propose that periprosthetic tissue reactions be thought of as (1) gross (metallosis, necrosis, cyst formation and pseudotumour); (2) histological (macrophage-dominated, lymphocyte-dominated or mixed); and (3) molecular (expression of inflammatory mediators and cytokines such as interleukin-6 and tumor necrosis factor-alpha). Taper corrosion and modularity is discussed, along with future research directions in this area.