Failure of a titanium endoprosthesis--a case report

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Medical device engineering

Background:

• Total hip arthroplasty (THA) is a common procedure for hip joint replacement.
• Titanium-based endoprostheses are widely used due to their biocompatibility and mechanical properties.
• Wear debris and component failure are critical concerns in THA longevity.

Observation:

• A titanium-head Thomson endoprosthesis required revision 2.5 years post-implantation.
• Significant metallosis and acetabular erosion were observed during revision surgery.
• The prosthesis stem and cement mantle remained in excellent condition.

Findings:

• The failure mode was primarily associated with the titanium head and its interaction with the acetabulum.
• Metallosis suggests adverse tissue reaction to wear particles from the bearing surface.
• Component integrity of the stem indicates the issue was localized to the articulating surfaces.

Implications:

• Titanium-alloy femoral heads may be prone to accelerated wear and subsequent metallosis in THA.
• Alternative bearing materials like cobalt-chrome or ceramic should be considered for titanium-stem THA.
• Further research is needed to optimize bearing surface materials for long-term THA success and patient outcomes.