Development of metal/metal hip resurfacing

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Medical device development

Background:

• Metal-on-metal hip resurfacing technology has evolved since the early 1990s.
• Early designs faced challenges including high wear, metallosis, and osteolysis, particularly when metal microstructure was altered by heat treatments.
• Previous iterations utilized hybrid fixation with specific component combinations.

Purpose of the Study:

• To introduce and evaluate the Birmingham Hip Resurfacing (BHR) implant.
• To assess the clinical performance and failure rates of the BHR implant.
• To highlight improvements in implant design and material processing compared to earlier metal-on-metal hip resurfacing systems.

Main Methods:

• Development of the BHR implant incorporating lessons from prior designs.
• Utilizing hybrid fixation with a porous ingrowth acetabular component.
• Employing an as-cast metal microstructure without post-casting heat treatments.

Main Results:

• The BHR implant has demonstrated a total failure rate of less than 1.0% in over 1,000 procedures performed in the last 4 years.
• This success contrasts with earlier issues of wear, metallosis, and osteolysis observed in hip resurfacing components.
• The improved design and material processing of the BHR appear to mitigate previous complications.

Conclusions:

• The Birmingham Hip Resurfacing implant represents a significant advancement in metal-on-metal hip resurfacing.
• The implant's design, fixation method, and material microstructure contribute to its low failure rate and clinical success.
• BHR offers a promising option for patients requiring hip resurfacing, with improved safety and efficacy profiles.