CoCrMo metal release in metal‐on‐highly crosslinked polyethylene hip implants

Abstract

Increasing cases of adverse local tissue reactions (ALTRs) associated with metal release have been observed in patients with metal‐on‐highly crosslinked polyethylene (MoP) hip implants, the most common design in total hip replacements. Studies have demonstrated the metal release from fretting corrosion at the head–neck junction, but rarely investigated tribocorrosion associated metal release at articulating surfaces in MoP hip implants. The objective of this study is to investigate both tribocorrosion at the articulating surfaces and fretting corrosion at the head–neck junction in CoCrMo femoral heads, as well as their association with metal species released in periprosthetic tissues and body fluids in MoP hip systems. Twenty‐three patients with ALTRs associated with MoP implants were included. Systematic analyses were performed on the wear damage in articulation, corrosion at the head–neck junction and their correlation with degradation products observed in synovial fluid, periprosthetic tissues, and serum. Results showed that tribocorrosion at the articulating surfaces contributed to the elevated concentration of both Co and Cr ions in serum, while fretting corrosion at the head–neck junction mainly released Co ions to serum. Both tribocorrosion at the articulating surfaces and fretting corrosion at the head–neck junction released particles rich in chromium and phosphate, the dominant particles found in synovial fluids and tissues. This study provides strong evidence that tribocorrosion at the articulating surfaces in MoP hip implants could result in significant metal release. This information should be taken into account when studying the mechanisms of ALTRs and developing strategies of preventing metal release in total hip replacements.

Metal Release from a Biomedical CoCrMo Alloy in Mixed Protein Solutions Under Static and Sliding Conditions: Effects of Protein Aggregation and Metal Precipitation

“…7b. This agrees with a previous study [37], which showed that tribocorrosion and fretting corrosion could induce the formation of particles, which contain more chromium. Also, these Cr and phosphate-enriched particles were mainly found in the synovial fluid [37].…”

Perivascular lymphocytic aggregates in hip prosthesis‐associated adverse local tissue reactions demonstrate Th1 and Th2 activity and exhausted CD8+ cell responses

“…2 ALTRs are presumed to be caused by a delayed hypersensitivity reaction to metallic corrosion or wear. [3][4][5][6] Both MoM and MoP-associated ALTRs are histologically characterized by synovial ulceration, necrosis, and mononuclear cell infiltration. 7 This immune infiltrate can vary from a diffused distribution of macrophages to the presence of organized perivascular lymphocytic aggregates that resemble tertiary lymphoid structures composed of highly organized, densely packed T and B cells.…”

The number of lymphocytes increases in the periprosthetic tissues with increasing time of implant service in non-metal-on-metal total joint arthroplasties: A role of metallic particles?

“…In fact, higher frequency of T lymphocytes is not only a domain of MoM pairs, it was also observed in the tissues around MoP total joint arthroplasties 36,37 . Modular connections, where fretting corrosion develops, are the main source of metallic particles and ions in non-MoM total joint arthroplasties 7,38 . A higher presence of CD4+ T lymphocytes was seen in dual modular neck hip prostheses 39 .…”