In vivo wear of titanium-alloy hip prostheses

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Histopathology

Background:

• Total hip arthroplasty (THA) is a common procedure to address hip joint degeneration.
• Previous THA studies focused on stainless steel or cobalt-chromium alloys, noting debris generation.
• Titanium-alloy components are increasingly used in THA revisions.

Purpose of the Study:

• To investigate the presence and characteristics of wear debris in tissues from revision THA involving titanium-alloy femoral components.
• To compare the histological reactions to debris with findings from earlier studies using different alloy types.

Main Methods:

• Analysis of tissue and component samples from twenty revision total hip arthroplasties.
• Microscopic examination for metallic, polyethylene, and methylmethacrylate debris.
• Histological assessment of tissue reactions to implant debris.

Main Results:

• Minute amounts of metallic debris were identified in tissues from two patients.
• The quantities of polyethylene and methylmethacrylate debris were comparable to those found in studies of older hip prostheses.
• Histological reactions observed were consistent with those reported for stainless steel and cobalt-chromium alloy implants.

Conclusions:

• Titanium-alloy femoral components in revision THA can generate metallic debris, though in minute amounts in this cohort.
• The tissue response and debris profile in titanium-alloy THA revisions appear similar to those seen with older prosthetic materials.
• Further research may be warranted to fully understand long-term wear characteristics of titanium alloys in THA.